Add openai codex support

internal/client/client_models.go

@@ -0,0 +1,159 @@
+// Package client defines the data structures used across all AI API clients.
+// These structures represent the common data models for requests, responses,
+// and configuration parameters used when communicating with various AI services.
+package client
+
+import "time"
+
+// ErrorMessage encapsulates an error with an associated HTTP status code.
+// This structure is used to provide detailed error information including
+// both the HTTP status and the underlying error.
+type ErrorMessage struct {
+	// StatusCode is the HTTP status code returned by the API.
+	StatusCode int
+
+	// Error is the underlying error that occurred.
+	Error error
+}
+
+// GCPProject represents the response structure for a Google Cloud project list request.
+// This structure is used when fetching available projects for a Google Cloud account.
+type GCPProject struct {
+	// Projects is a list of Google Cloud projects accessible by the user.
+	Projects []GCPProjectProjects `json:"projects"`
+}
+
+// GCPProjectLabels defines the labels associated with a GCP project.
+// These labels can contain metadata about the project's purpose or configuration.
+type GCPProjectLabels struct {
+	// GenerativeLanguage indicates if the project has generative language APIs enabled.
+	GenerativeLanguage string `json:"generative-language"`
+}
+
+// GCPProjectProjects contains details about a single Google Cloud project.
+// This includes identifying information, metadata, and configuration details.
+type GCPProjectProjects struct {
+	// ProjectNumber is the unique numeric identifier for the project.
+	ProjectNumber string `json:"projectNumber"`
+
+	// ProjectID is the unique string identifier for the project.
+	ProjectID string `json:"projectId"`
+
+	// LifecycleState indicates the current state of the project (e.g., "ACTIVE").
+	LifecycleState string `json:"lifecycleState"`
+
+	// Name is the human-readable name of the project.
+	Name string `json:"name"`
+
+	// Labels contains metadata labels associated with the project.
+	Labels GCPProjectLabels `json:"labels"`
+
+	// CreateTime is the timestamp when the project was created.
+	CreateTime time.Time `json:"createTime"`
+}
+
+// Content represents a single message in a conversation, with a role and parts.
+// This structure models a message exchange between a user and an AI model.
+type Content struct {
+	// Role indicates who sent the message ("user", "model", or "tool").
+	Role string `json:"role"`
+
+	// Parts is a collection of content parts that make up the message.
+	Parts []Part `json:"parts"`
+}
+
+// Part represents a distinct piece of content within a message.
+// A part can be text, inline data (like an image), a function call, or a function response.
+type Part struct {
+	// Text contains plain text content.
+	Text string `json:"text,omitempty"`
+
+	// InlineData contains base64-encoded data with its MIME type (e.g., images).
+	InlineData *InlineData `json:"inlineData,omitempty"`
+
+	// FunctionCall represents a tool call requested by the model.
+	FunctionCall *FunctionCall `json:"functionCall,omitempty"`
+
+	// FunctionResponse represents the result of a tool execution.
+	FunctionResponse *FunctionResponse `json:"functionResponse,omitempty"`
+}
+
+// InlineData represents base64-encoded data with its MIME type.
+// This is typically used for embedding images or other binary data in requests.
+type InlineData struct {
+	// MimeType specifies the media type of the embedded data (e.g., "image/png").
+	MimeType string `json:"mime_type,omitempty"`
+
+	// Data contains the base64-encoded binary data.
+	Data string `json:"data,omitempty"`
+}
+
+// FunctionCall represents a tool call requested by the model.
+// It includes the function name and its arguments that the model wants to execute.
+type FunctionCall struct {
+	// Name is the identifier of the function to be called.
+	Name string `json:"name"`
+
+	// Args contains the arguments to pass to the function.
+	Args map[string]interface{} `json:"args"`
+}
+
+// FunctionResponse represents the result of a tool execution.
+// This is sent back to the model after a tool call has been processed.
+type FunctionResponse struct {
+	// Name is the identifier of the function that was called.
+	Name string `json:"name"`
+
+	// Response contains the result data from the function execution.
+	Response map[string]interface{} `json:"response"`
+}
+
+// GenerateContentRequest is the top-level request structure for the streamGenerateContent endpoint.
+// This structure defines all the parameters needed for generating content from an AI model.
+type GenerateContentRequest struct {
+	// SystemInstruction provides system-level instructions that guide the model's behavior.
+	SystemInstruction *Content `json:"systemInstruction,omitempty"`
+
+	// Contents is the conversation history between the user and the model.
+	Contents []Content `json:"contents"`
+
+	// Tools defines the available tools/functions that the model can call.
+	Tools []ToolDeclaration `json:"tools,omitempty"`
+
+	// GenerationConfig contains parameters that control the model's generation behavior.
+	GenerationConfig `json:"generationConfig"`
+}
+
+// GenerationConfig defines parameters that control the model's generation behavior.
+// These parameters affect the creativity, randomness, and reasoning of the model's responses.
+type GenerationConfig struct {
+	// ThinkingConfig specifies configuration for the model's "thinking" process.
+	ThinkingConfig GenerationConfigThinkingConfig `json:"thinkingConfig,omitempty"`
+
+	// Temperature controls the randomness of the model's responses.
+	// Values closer to 0 make responses more deterministic, while values closer to 1 increase randomness.
+	Temperature float64 `json:"temperature,omitempty"`
+
+	// TopP controls nucleus sampling, which affects the diversity of responses.
+	// It limits the model to consider only the top P% of probability mass.
+	TopP float64 `json:"topP,omitempty"`
+
+	// TopK limits the model to consider only the top K most likely tokens.
+	// This can help control the quality and diversity of generated text.
+	TopK float64 `json:"topK,omitempty"`
+}
+
+// GenerationConfigThinkingConfig specifies configuration for the model's "thinking" process.
+// This controls whether the model should output its reasoning process along with the final answer.
+type GenerationConfigThinkingConfig struct {
+	// IncludeThoughts determines whether the model should output its reasoning process.
+	// When enabled, the model will include its step-by-step thinking in the response.
+	IncludeThoughts bool `json:"include_thoughts,omitempty"`
+}
+
+// ToolDeclaration defines the structure for declaring tools (like functions)
+// that the model can call during content generation.
+type ToolDeclaration struct {
+	// FunctionDeclarations is a list of available functions that the model can call.
+	FunctionDeclarations []interface{} `json:"functionDeclarations"`
+}

internal/client/codex_client.go

@@ -0,0 +1,258 @@
+package client
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/luispater/CLIProxyAPI/internal/auth"
+	"github.com/luispater/CLIProxyAPI/internal/auth/codex"
+	"github.com/luispater/CLIProxyAPI/internal/config"
+	"github.com/luispater/CLIProxyAPI/internal/util"
+	log "github.com/sirupsen/logrus"
+	"github.com/tidwall/gjson"
+)
+
+const (
+	chatGPTEndpoint = "https://chatgpt.com/backend-api"
+)
+
+// CodexClient implements the Client interface for OpenAI API
+type CodexClient struct {
+	ClientBase
+	codexAuth *codex.CodexAuth
+}
+
+// NewCodexClient creates a new OpenAI client instance
+func NewCodexClient(cfg *config.Config, ts *codex.CodexTokenStorage) (*CodexClient, error) {
+	httpClient := util.SetProxy(cfg, &http.Client{})
+	client := &CodexClient{
+		ClientBase: ClientBase{
+			RequestMutex:       &sync.Mutex{},
+			httpClient:         httpClient,
+			cfg:                cfg,
+			modelQuotaExceeded: make(map[string]*time.Time),
+			tokenStorage:       ts,
+		},
+		codexAuth: codex.NewCodexAuth(cfg),
+	}
+
+	return client, nil
+}
+
+// GetUserAgent returns the user agent string for OpenAI API requests
+func (c *CodexClient) GetUserAgent() string {
+	return "codex-cli"
+}
+
+func (c *CodexClient) TokenStorage() auth.TokenStorage {
+	return c.tokenStorage
+}
+
+// SendMessage sends a message to OpenAI API (non-streaming)
+func (c *CodexClient) SendMessage(_ context.Context, _ []byte, _ string, _ *Content, _ []Content, _ []ToolDeclaration) ([]byte, *ErrorMessage) {
+	// For now, return an error as OpenAI integration is not fully implemented
+	return nil, &ErrorMessage{
+		StatusCode: http.StatusNotImplemented,
+		Error:      fmt.Errorf("codex message sending not yet implemented"),
+	}
+}
+
+// SendMessageStream sends a streaming message to OpenAI API
+func (c *CodexClient) SendMessageStream(_ context.Context, _ []byte, _ string, _ *Content, _ []Content, _ []ToolDeclaration, _ ...bool) (<-chan []byte, <-chan *ErrorMessage) {
+	errChan := make(chan *ErrorMessage, 1)
+	errChan <- &ErrorMessage{
+		StatusCode: http.StatusNotImplemented,
+		Error:      fmt.Errorf("codex streaming not yet implemented"),
+	}
+	close(errChan)
+
+	return nil, errChan
+}
+
+// SendRawMessage sends a raw message to OpenAI API
+func (c *CodexClient) SendRawMessage(ctx context.Context, rawJSON []byte, alt string) ([]byte, *ErrorMessage) {
+	modelResult := gjson.GetBytes(rawJSON, "model")
+	model := modelResult.String()
+	modelName := model
+
+	respBody, err := c.APIRequest(ctx, "/codex/responses", rawJSON, alt, false)
+	if err != nil {
+		if err.StatusCode == 429 {
+			now := time.Now()
+			c.modelQuotaExceeded[modelName] = &now
+		}
+		return nil, err
+	}
+	delete(c.modelQuotaExceeded, modelName)
+	bodyBytes, errReadAll := io.ReadAll(respBody)
+	if errReadAll != nil {
+		return nil, &ErrorMessage{StatusCode: 500, Error: errReadAll}
+	}
+	return bodyBytes, nil
+
+}
+
+// SendRawMessageStream sends a raw streaming message to OpenAI API
+func (c *CodexClient) SendRawMessageStream(ctx context.Context, rawJSON []byte, alt string) (<-chan []byte, <-chan *ErrorMessage) {
+	errChan := make(chan *ErrorMessage)
+	dataChan := make(chan []byte)
+	go func() {
+		defer close(errChan)
+		defer close(dataChan)
+
+		modelResult := gjson.GetBytes(rawJSON, "model")
+		model := modelResult.String()
+		modelName := model
+		var stream io.ReadCloser
+		for {
+			var err *ErrorMessage
+			stream, err = c.APIRequest(ctx, "/codex/responses", rawJSON, alt, true)
+			if err != nil {
+				if err.StatusCode == 429 {
+					now := time.Now()
+					c.modelQuotaExceeded[modelName] = &now
+				}
+				errChan <- err
+				return
+			}
+			delete(c.modelQuotaExceeded, modelName)
+			break
+		}
+
+		scanner := bufio.NewScanner(stream)
+		buffer := make([]byte, 10240*1024)
+		scanner.Buffer(buffer, 10240*1024)
+		for scanner.Scan() {
+			line := scanner.Bytes()
+			dataChan <- line
+		}
+
+		if errScanner := scanner.Err(); errScanner != nil {
+			errChan <- &ErrorMessage{500, errScanner}
+			_ = stream.Close()
+			return
+		}
+
+		_ = stream.Close()
+	}()
+
+	return dataChan, errChan
+}
+
+// SendRawTokenCount sends a token count request to OpenAI API
+func (c *CodexClient) SendRawTokenCount(_ context.Context, _ []byte, _ string) ([]byte, *ErrorMessage) {
+	return nil, &ErrorMessage{
+		StatusCode: http.StatusNotImplemented,
+		Error:      fmt.Errorf("codex token counting not yet implemented"),
+	}
+}
+
+// SaveTokenToFile persists the token storage to disk
+func (c *CodexClient) SaveTokenToFile() error {
+	fileName := filepath.Join(c.cfg.AuthDir, fmt.Sprintf("codex-%s.json", c.tokenStorage.(*codex.CodexTokenStorage).Email))
+	return c.tokenStorage.SaveTokenToFile(fileName)
+}
+
+// RefreshTokens refreshes the access tokens if needed
+func (c *CodexClient) RefreshTokens(ctx context.Context) error {
+	if c.tokenStorage == nil || c.tokenStorage.(*codex.CodexTokenStorage).RefreshToken == "" {
+		return fmt.Errorf("no refresh token available")
+	}
+
+	// Refresh tokens using the auth service
+	newTokenData, err := c.codexAuth.RefreshTokensWithRetry(ctx, c.tokenStorage.(*codex.CodexTokenStorage).RefreshToken, 3)
+	if err != nil {
+		return fmt.Errorf("failed to refresh tokens: %w", err)
+	}
+
+	// Update token storage
+	c.codexAuth.UpdateTokenStorage(c.tokenStorage.(*codex.CodexTokenStorage), newTokenData)
+
+	// Save updated tokens
+	if err = c.SaveTokenToFile(); err != nil {
+		log.Warnf("Failed to save refreshed tokens: %v", err)
+	}
+
+	log.Debug("codex tokens refreshed successfully")
+	return nil
+}
+
+// APIRequest handles making requests to the CLI API endpoints.
+func (c *CodexClient) APIRequest(ctx context.Context, endpoint string, body interface{}, _ string, _ bool) (io.ReadCloser, *ErrorMessage) {
+	var jsonBody []byte
+	var err error
+	if byteBody, ok := body.([]byte); ok {
+		jsonBody = byteBody
+	} else {
+		jsonBody, err = json.Marshal(body)
+		if err != nil {
+			return nil, &ErrorMessage{500, fmt.Errorf("failed to marshal request body: %w", err)}
+		}
+	}
+
+	url := fmt.Sprintf("%s/%s", chatGPTEndpoint, endpoint)
+
+	// log.Debug(string(jsonBody))
+	// log.Debug(url)
+	reqBody := bytes.NewBuffer(jsonBody)
+
+	req, err := http.NewRequestWithContext(ctx, "POST", url, reqBody)
+	if err != nil {
+		return nil, &ErrorMessage{500, fmt.Errorf("failed to create request: %v", err)}
+	}
+
+	sessionID := uuid.New().String()
+	// Set headers
+	req.Header.Set("Version", "0.21.0")
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Openai-Beta", "responses=experimental")
+	req.Header.Set("Session_id", sessionID)
+	req.Header.Set("Accept", "text/event-stream")
+	req.Header.Set("Chatgpt-Account-Id", c.tokenStorage.(*codex.CodexTokenStorage).AccountID)
+	req.Header.Set("Originator", "codex_cli_rs")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", c.tokenStorage.(*codex.CodexTokenStorage).AccessToken))
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, &ErrorMessage{500, fmt.Errorf("failed to execute request: %v", err)}
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		defer func() {
+			if err = resp.Body.Close(); err != nil {
+				log.Printf("warn: failed to close response body: %v", err)
+			}
+		}()
+		bodyBytes, _ := io.ReadAll(resp.Body)
+		// log.Debug(string(jsonBody))
+		return nil, &ErrorMessage{resp.StatusCode, fmt.Errorf(string(bodyBytes))}
+	}
+
+	return resp.Body, nil
+}
+
+func (c *CodexClient) GetEmail() string {
+	return c.tokenStorage.(*codex.CodexTokenStorage).Email
+}
+
+// IsModelQuotaExceeded returns true if the specified model has exceeded its quota
+// and no fallback options are available.
+func (c *CodexClient) IsModelQuotaExceeded(model string) bool {
+	if lastExceededTime, hasKey := c.modelQuotaExceeded[model]; hasKey {
+		duration := time.Now().Sub(*lastExceededTime)
+		if duration > 30*time.Minute {
+			return false
+		}
+		return true
+	}
+	return false
+}

internal/client/gemini_client.go

@@ -0,0 +1,942 @@
+// Package client provides HTTP client functionality for interacting with Google Cloud AI APIs.
+// It handles OAuth2 authentication, token management, request/response processing,
+// streaming communication, quota management, and automatic model fallback.
+// The package supports both direct API key authentication and OAuth2 flows.
+package client
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	geminiAuth "github.com/luispater/CLIProxyAPI/internal/auth/gemini"
+	"github.com/luispater/CLIProxyAPI/internal/config"
+	log "github.com/sirupsen/logrus"
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
+	"golang.org/x/oauth2"
+)
+
+const (
+	codeAssistEndpoint = "https://cloudcode-pa.googleapis.com"
+	apiVersion         = "v1internal"
+
+	glEndPoint   = "https://generativelanguage.googleapis.com"
+	glAPIVersion = "v1beta"
+)
+
+var (
+	previewModels = map[string][]string{
+		"gemini-2.5-pro":   {"gemini-2.5-pro-preview-05-06", "gemini-2.5-pro-preview-06-05"},
+		"gemini-2.5-flash": {"gemini-2.5-flash-preview-04-17", "gemini-2.5-flash-preview-05-20"},
+	}
+)
+
+// GeminiClient is the main client for interacting with the CLI API.
+type GeminiClient struct {
+	ClientBase
+	glAPIKey string
+}
+
+// NewGeminiClient creates a new CLI API client.
+func NewGeminiClient(httpClient *http.Client, ts *geminiAuth.GeminiTokenStorage, cfg *config.Config, glAPIKey ...string) *GeminiClient {
+	var glKey string
+	if len(glAPIKey) > 0 {
+		glKey = glAPIKey[0]
+	}
+	return &GeminiClient{
+		ClientBase: ClientBase{
+			RequestMutex:       &sync.Mutex{},
+			httpClient:         httpClient,
+			cfg:                cfg,
+			tokenStorage:       ts,
+			modelQuotaExceeded: make(map[string]*time.Time),
+		},
+		glAPIKey: glKey,
+	}
+}
+
+// SetProjectID updates the project ID for the client's token storage.
+func (c *GeminiClient) SetProjectID(projectID string) {
+	c.tokenStorage.(*geminiAuth.GeminiTokenStorage).ProjectID = projectID
+}
+
+// SetIsAuto configures whether the client should operate in automatic mode.
+func (c *GeminiClient) SetIsAuto(auto bool) {
+	c.tokenStorage.(*geminiAuth.GeminiTokenStorage).Auto = auto
+}
+
+// SetIsChecked sets the checked status for the client's token storage.
+func (c *GeminiClient) SetIsChecked(checked bool) {
+	c.tokenStorage.(*geminiAuth.GeminiTokenStorage).Checked = checked
+}
+
+// IsChecked returns whether the client's token storage has been checked.
+func (c *GeminiClient) IsChecked() bool {
+	return c.tokenStorage.(*geminiAuth.GeminiTokenStorage).Checked
+}
+
+// IsAuto returns whether the client is operating in automatic mode.
+func (c *GeminiClient) IsAuto() bool {
+	return c.tokenStorage.(*geminiAuth.GeminiTokenStorage).Auto
+}
+
+// GetEmail returns the email address associated with the client's token storage.
+func (c *GeminiClient) GetEmail() string {
+	return c.tokenStorage.(*geminiAuth.GeminiTokenStorage).Email
+}
+
+// GetProjectID returns the Google Cloud project ID from the client's token storage.
+func (c *GeminiClient) GetProjectID() string {
+	if c.glAPIKey == "" && c.tokenStorage != nil {
+		if ts, ok := c.tokenStorage.(*geminiAuth.GeminiTokenStorage); ok {
+			return ts.ProjectID
+		}
+	}
+	return ""
+}
+
+// GetGenerativeLanguageAPIKey returns the generative language API key if configured.
+func (c *GeminiClient) GetGenerativeLanguageAPIKey() string {
+	return c.glAPIKey
+}
+
+// SetupUser performs the initial user onboarding and setup.
+func (c *GeminiClient) SetupUser(ctx context.Context, email, projectID string) error {
+	c.tokenStorage.(*geminiAuth.GeminiTokenStorage).Email = email
+	log.Info("Performing user onboarding...")
+
+	// 1. LoadCodeAssist
+	loadAssistReqBody := map[string]interface{}{
+		"metadata": c.getClientMetadata(),
+	}
+	if projectID != "" {
+		loadAssistReqBody["cloudaicompanionProject"] = projectID
+	}
+
+	var loadAssistResp map[string]interface{}
+	err := c.makeAPIRequest(ctx, "loadCodeAssist", "POST", loadAssistReqBody, &loadAssistResp)
+	if err != nil {
+		return fmt.Errorf("failed to load code assist: %w", err)
+	}
+
+	// a, _ := json.Marshal(&loadAssistResp)
+	// log.Debug(string(a))
+	//
+	// a, _ = json.Marshal(loadAssistReqBody)
+	// log.Debug(string(a))
+
+	// 2. OnboardUser
+	var onboardTierID = "legacy-tier"
+	if tiers, ok := loadAssistResp["allowedTiers"].([]interface{}); ok {
+		for _, t := range tiers {
+			if tier, tierOk := t.(map[string]interface{}); tierOk {
+				if isDefault, isDefaultOk := tier["isDefault"].(bool); isDefaultOk && isDefault {
+					if id, idOk := tier["id"].(string); idOk {
+						onboardTierID = id
+						break
+					}
+				}
+			}
+		}
+	}
+
+	onboardProjectID := projectID
+	if p, ok := loadAssistResp["cloudaicompanionProject"].(string); ok && p != "" {
+		onboardProjectID = p
+	}
+
+	onboardReqBody := map[string]interface{}{
+		"tierId":   onboardTierID,
+		"metadata": c.getClientMetadata(),
+	}
+	if onboardProjectID != "" {
+		onboardReqBody["cloudaicompanionProject"] = onboardProjectID
+	} else {
+		return fmt.Errorf("failed to start user onboarding, need define a project id")
+	}
+
+	for {
+		var lroResp map[string]interface{}
+		err = c.makeAPIRequest(ctx, "onboardUser", "POST", onboardReqBody, &lroResp)
+		if err != nil {
+			return fmt.Errorf("failed to start user onboarding: %w", err)
+		}
+		// a, _ := json.Marshal(&lroResp)
+		// log.Debug(string(a))
+
+		// 3. Poll Long-Running Operation (LRO)
+		done, doneOk := lroResp["done"].(bool)
+		if doneOk && done {
+			if project, projectOk := lroResp["response"].(map[string]interface{})["cloudaicompanionProject"].(map[string]interface{}); projectOk {
+				if projectID != "" {
+					c.tokenStorage.(*geminiAuth.GeminiTokenStorage).ProjectID = projectID
+				} else {
+					c.tokenStorage.(*geminiAuth.GeminiTokenStorage).ProjectID = project["id"].(string)
+				}
+				log.Infof("Onboarding complete. Using Project ID: %s", c.tokenStorage.(*geminiAuth.GeminiTokenStorage).ProjectID)
+				return nil
+			}
+		} else {
+			log.Println("Onboarding in progress, waiting 5 seconds...")
+			time.Sleep(5 * time.Second)
+		}
+	}
+}
+
+// makeAPIRequest handles making requests to the CLI API endpoints.
+func (c *GeminiClient) makeAPIRequest(ctx context.Context, endpoint, method string, body interface{}, result interface{}) error {
+	var reqBody io.Reader
+	if body != nil {
+		jsonBody, err := json.Marshal(body)
+		if err != nil {
+			return fmt.Errorf("failed to marshal request body: %w", err)
+		}
+		reqBody = bytes.NewBuffer(jsonBody)
+	}
+
+	url := fmt.Sprintf("%s/%s:%s", codeAssistEndpoint, apiVersion, endpoint)
+	if strings.HasPrefix(endpoint, "operations/") {
+		url = fmt.Sprintf("%s/%s", codeAssistEndpoint, endpoint)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, method, url, reqBody)
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+
+	token, err := c.httpClient.Transport.(*oauth2.Transport).Source.Token()
+	if err != nil {
+		return fmt.Errorf("failed to get token: %w", err)
+	}
+
+	// Set headers
+	metadataStr := c.getClientMetadataString()
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("User-Agent", c.GetUserAgent())
+	req.Header.Set("X-Goog-Api-Client", "gl-node/22.17.0")
+	req.Header.Set("Client-Metadata", metadataStr)
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token.AccessToken))
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to execute request: %w", err)
+	}
+	defer func() {
+		if err = resp.Body.Close(); err != nil {
+			log.Printf("warn: failed to close response body: %v", err)
+		}
+	}()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		bodyBytes, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("api request failed with status %d: %s", resp.StatusCode, string(bodyBytes))
+	}
+
+	if result != nil {
+		if err = json.NewDecoder(resp.Body).Decode(result); err != nil {
+			return fmt.Errorf("failed to decode response body: %w", err)
+		}
+	}
+
+	return nil
+}
+
+// APIRequest handles making requests to the CLI API endpoints.
+func (c *GeminiClient) APIRequest(ctx context.Context, endpoint string, body interface{}, alt string, stream bool) (io.ReadCloser, *ErrorMessage) {
+	var jsonBody []byte
+	var err error
+	if byteBody, ok := body.([]byte); ok {
+		jsonBody = byteBody
+	} else {
+		jsonBody, err = json.Marshal(body)
+		if err != nil {
+			return nil, &ErrorMessage{500, fmt.Errorf("failed to marshal request body: %w", err)}
+		}
+	}
+
+	var url string
+	if c.glAPIKey == "" {
+		// Add alt=sse for streaming
+		url = fmt.Sprintf("%s/%s:%s", codeAssistEndpoint, apiVersion, endpoint)
+		if alt == "" && stream {
+			url = url + "?alt=sse"
+		} else {
+			if alt != "" {
+				url = url + fmt.Sprintf("?$alt=%s", alt)
+			}
+		}
+	} else {
+		if endpoint == "countTokens" {
+			modelResult := gjson.GetBytes(jsonBody, "model")
+			url = fmt.Sprintf("%s/%s/models/%s:%s", glEndPoint, glAPIVersion, modelResult.String(), endpoint)
+		} else {
+			modelResult := gjson.GetBytes(jsonBody, "model")
+			url = fmt.Sprintf("%s/%s/models/%s:%s", glEndPoint, glAPIVersion, modelResult.String(), endpoint)
+			if alt == "" && stream {
+				url = url + "?alt=sse"
+			} else {
+				if alt != "" {
+					url = url + fmt.Sprintf("?$alt=%s", alt)
+				}
+			}
+			jsonBody = []byte(gjson.GetBytes(jsonBody, "request").Raw)
+			systemInstructionResult := gjson.GetBytes(jsonBody, "systemInstruction")
+			if systemInstructionResult.Exists() {
+				jsonBody, _ = sjson.SetRawBytes(jsonBody, "system_instruction", []byte(systemInstructionResult.Raw))
+				jsonBody, _ = sjson.DeleteBytes(jsonBody, "systemInstruction")
+				jsonBody, _ = sjson.DeleteBytes(jsonBody, "session_id")
+			}
+		}
+	}
+
+	// log.Debug(string(jsonBody))
+	// log.Debug(url)
+	reqBody := bytes.NewBuffer(jsonBody)
+
+	req, err := http.NewRequestWithContext(ctx, "POST", url, reqBody)
+	if err != nil {
+		return nil, &ErrorMessage{500, fmt.Errorf("failed to create request: %v", err)}
+	}
+
+	// Set headers
+	metadataStr := c.getClientMetadataString()
+	req.Header.Set("Content-Type", "application/json")
+	if c.glAPIKey == "" {
+		token, errToken := c.httpClient.Transport.(*oauth2.Transport).Source.Token()
+		if errToken != nil {
+			return nil, &ErrorMessage{500, fmt.Errorf("failed to get token: %v", errToken)}
+		}
+		req.Header.Set("User-Agent", c.GetUserAgent())
+		req.Header.Set("X-Goog-Api-Client", "gl-node/22.17.0")
+		req.Header.Set("Client-Metadata", metadataStr)
+		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token.AccessToken))
+	} else {
+		req.Header.Set("x-goog-api-key", c.glAPIKey)
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, &ErrorMessage{500, fmt.Errorf("failed to execute request: %v", err)}
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		defer func() {
+			if err = resp.Body.Close(); err != nil {
+				log.Printf("warn: failed to close response body: %v", err)
+			}
+		}()
+		bodyBytes, _ := io.ReadAll(resp.Body)
+		// log.Debug(string(jsonBody))
+		return nil, &ErrorMessage{resp.StatusCode, fmt.Errorf(string(bodyBytes))}
+	}
+
+	return resp.Body, nil
+}
+
+// SendMessage handles a single conversational turn, including tool calls.
+func (c *GeminiClient) SendMessage(ctx context.Context, rawJSON []byte, model string, systemInstruction *Content, contents []Content, tools []ToolDeclaration) ([]byte, *ErrorMessage) {
+	request := GenerateContentRequest{
+		Contents: contents,
+		GenerationConfig: GenerationConfig{
+			ThinkingConfig: GenerationConfigThinkingConfig{
+				IncludeThoughts: true,
+			},
+		},
+	}
+
+	request.SystemInstruction = systemInstruction
+
+	request.Tools = tools
+
+	requestBody := map[string]interface{}{
+		"project": c.GetProjectID(), // Assuming ProjectID is available
+		"request": request,
+		"model":   model,
+	}
+
+	byteRequestBody, _ := json.Marshal(requestBody)
+
+	// log.Debug(string(byteRequestBody))
+
+	reasoningEffortResult := gjson.GetBytes(rawJSON, "reasoning_effort")
+	if reasoningEffortResult.String() == "none" {
+		byteRequestBody, _ = sjson.DeleteBytes(byteRequestBody, "request.generationConfig.thinkingConfig.include_thoughts")
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 0)
+	} else if reasoningEffortResult.String() == "auto" {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", -1)
+	} else if reasoningEffortResult.String() == "low" {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 1024)
+	} else if reasoningEffortResult.String() == "medium" {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 8192)
+	} else if reasoningEffortResult.String() == "high" {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 24576)
+	} else {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", -1)
+	}
+
+	temperatureResult := gjson.GetBytes(rawJSON, "temperature")
+	if temperatureResult.Exists() && temperatureResult.Type == gjson.Number {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.temperature", temperatureResult.Num)
+	}
+
+	topPResult := gjson.GetBytes(rawJSON, "top_p")
+	if topPResult.Exists() && topPResult.Type == gjson.Number {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.topP", topPResult.Num)
+	}
+
+	topKResult := gjson.GetBytes(rawJSON, "top_k")
+	if topKResult.Exists() && topKResult.Type == gjson.Number {
+		byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.topK", topKResult.Num)
+	}
+
+	modelName := model
+	// log.Debug(string(byteRequestBody))
+	for {
+		if c.isModelQuotaExceeded(modelName) {
+			if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+				modelName = c.getPreviewModel(model)
+				if modelName != "" {
+					log.Debugf("Model %s is quota exceeded. Switch to preview model %s", model, modelName)
+					byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "model", modelName)
+					continue
+				}
+			}
+			return nil, &ErrorMessage{
+				StatusCode: 429,
+				Error:      fmt.Errorf(`{"error":{"code":429,"message":"All the models of '%s' are quota exceeded","status":"RESOURCE_EXHAUSTED"}}`, model),
+			}
+		}
+
+		respBody, err := c.APIRequest(ctx, "generateContent", byteRequestBody, "", false)
+		if err != nil {
+			if err.StatusCode == 429 {
+				now := time.Now()
+				c.modelQuotaExceeded[modelName] = &now
+				if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+					continue
+				}
+			}
+			return nil, err
+		}
+		delete(c.modelQuotaExceeded, modelName)
+		bodyBytes, errReadAll := io.ReadAll(respBody)
+		if errReadAll != nil {
+			return nil, &ErrorMessage{StatusCode: 500, Error: errReadAll}
+		}
+		return bodyBytes, nil
+	}
+}
+
+// SendMessageStream handles streaming conversational turns with comprehensive parameter management.
+// This function implements a sophisticated streaming system that supports tool calls, reasoning modes,
+// quota management, and automatic model fallback. It returns two channels for asynchronous communication:
+// one for streaming response data and another for error handling.
+func (c *GeminiClient) SendMessageStream(ctx context.Context, rawJSON []byte, model string, systemInstruction *Content, contents []Content, tools []ToolDeclaration, includeThoughts ...bool) (<-chan []byte, <-chan *ErrorMessage) {
+	// Define the data prefix used in Server-Sent Events streaming format
+	dataTag := []byte("data: ")
+
+	// Create channels for asynchronous communication
+	// errChan: delivers error messages during streaming
+	// dataChan: delivers response data chunks
+	errChan := make(chan *ErrorMessage)
+	dataChan := make(chan []byte)
+
+	// Launch a goroutine to handle the streaming process asynchronously
+	// This allows the function to return immediately while processing continues in the background
+	go func() {
+		// Ensure channels are properly closed when the goroutine exits
+		defer close(errChan)
+		defer close(dataChan)
+
+		// Configure thinking/reasoning capabilities
+		// Default to including thoughts unless explicitly disabled
+		includeThoughtsFlag := true
+		if len(includeThoughts) > 0 {
+			includeThoughtsFlag = includeThoughts[0]
+		}
+
+		// Build the base request structure for the Gemini API
+		// This includes conversation contents and generation configuration
+		request := GenerateContentRequest{
+			Contents: contents,
+			GenerationConfig: GenerationConfig{
+				ThinkingConfig: GenerationConfigThinkingConfig{
+					IncludeThoughts: includeThoughtsFlag,
+				},
+			},
+		}
+
+		// Add system instructions if provided
+		// System instructions guide the AI's behavior and response style
+		request.SystemInstruction = systemInstruction
+
+		// Add available tools for function calling capabilities
+		// Tools allow the AI to perform actions beyond text generation
+		request.Tools = tools
+
+		// Construct the complete request body with project context
+		// The project ID is essential for proper API routing and billing
+		requestBody := map[string]interface{}{
+			"project": c.GetProjectID(), // Project ID for API routing and quota management
+			"request": request,
+			"model":   model,
+		}
+
+		// Serialize the request body to JSON for API transmission
+		byteRequestBody, _ := json.Marshal(requestBody)
+
+		// Parse and configure reasoning effort levels from the original request
+		// This maps Claude-style reasoning effort parameters to Gemini's thinking budget system
+		reasoningEffortResult := gjson.GetBytes(rawJSON, "reasoning_effort")
+		if reasoningEffortResult.String() == "none" {
+			// Disable thinking entirely for fastest responses
+			byteRequestBody, _ = sjson.DeleteBytes(byteRequestBody, "request.generationConfig.thinkingConfig.include_thoughts")
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 0)
+		} else if reasoningEffortResult.String() == "auto" {
+			// Let the model decide the appropriate thinking budget automatically
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", -1)
+		} else if reasoningEffortResult.String() == "low" {
+			// Minimal thinking for simple tasks (1KB thinking budget)
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 1024)
+		} else if reasoningEffortResult.String() == "medium" {
+			// Moderate thinking for complex tasks (8KB thinking budget)
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 8192)
+		} else if reasoningEffortResult.String() == "high" {
+			// Maximum thinking for very complex tasks (24KB thinking budget)
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", 24576)
+		} else {
+			// Default to automatic thinking budget if no specific level is provided
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.thinkingConfig.thinkingBudget", -1)
+		}
+
+		// Configure temperature parameter for response randomness control
+		// Temperature affects the creativity vs consistency trade-off in responses
+		temperatureResult := gjson.GetBytes(rawJSON, "temperature")
+		if temperatureResult.Exists() && temperatureResult.Type == gjson.Number {
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.temperature", temperatureResult.Num)
+		}
+
+		// Configure top-p parameter for nucleus sampling
+		// Controls the cumulative probability threshold for token selection
+		topPResult := gjson.GetBytes(rawJSON, "top_p")
+		if topPResult.Exists() && topPResult.Type == gjson.Number {
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.topP", topPResult.Num)
+		}
+
+		// Configure top-k parameter for limiting token candidates
+		// Restricts the model to consider only the top K most likely tokens
+		topKResult := gjson.GetBytes(rawJSON, "top_k")
+		if topKResult.Exists() && topKResult.Type == gjson.Number {
+			byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "request.generationConfig.topK", topKResult.Num)
+		}
+
+		// Initialize model name for quota management and potential fallback
+		modelName := model
+		var stream io.ReadCloser
+
+		// Quota management and model fallback loop
+		// This loop handles quota exceeded scenarios and automatic model switching
+		for {
+			// Check if the current model has exceeded its quota
+			if c.isModelQuotaExceeded(modelName) {
+				// Attempt to switch to a preview model if configured and using account auth
+				if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+					modelName = c.getPreviewModel(model)
+					if modelName != "" {
+						log.Debugf("Model %s is quota exceeded. Switch to preview model %s", model, modelName)
+						// Update the request body with the new model name
+						byteRequestBody, _ = sjson.SetBytes(byteRequestBody, "model", modelName)
+						continue // Retry with the preview model
+					}
+				}
+				// If no fallback is available, return a quota exceeded error
+				errChan <- &ErrorMessage{
+					StatusCode: 429,
+					Error:      fmt.Errorf(`{"error":{"code":429,"message":"All the models of '%s' are quota exceeded","status":"RESOURCE_EXHAUSTED"}}`, model),
+				}
+				return
+			}
+
+			// Attempt to establish a streaming connection with the API
+			var err *ErrorMessage
+			stream, err = c.APIRequest(ctx, "streamGenerateContent", byteRequestBody, "", true)
+			if err != nil {
+				// Handle quota exceeded errors by marking the model and potentially retrying
+				if err.StatusCode == 429 {
+					now := time.Now()
+					c.modelQuotaExceeded[modelName] = &now // Mark model as quota exceeded
+					// If preview model switching is enabled, retry the loop
+					if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+						continue
+					}
+				}
+				// Forward other errors to the error channel
+				errChan <- err
+				return
+			}
+			// Clear any previous quota exceeded status for this model
+			delete(c.modelQuotaExceeded, modelName)
+			break // Successfully established connection, exit the retry loop
+		}
+
+		// Process the streaming response using a scanner
+		// This handles the Server-Sent Events format from the API
+		scanner := bufio.NewScanner(stream)
+		for scanner.Scan() {
+			line := scanner.Bytes()
+			// Filter and forward only data lines (those prefixed with "data: ")
+			// This extracts the actual JSON content from the SSE format
+			if bytes.HasPrefix(line, dataTag) {
+				dataChan <- line[6:] // Remove "data: " prefix and send the JSON content
+			}
+		}
+
+		// Handle any scanning errors that occurred during stream processing
+		if errScanner := scanner.Err(); errScanner != nil {
+			// Send a 500 Internal Server Error for scanning failures
+			errChan <- &ErrorMessage{500, errScanner}
+			_ = stream.Close()
+			return
+		}
+
+		// Ensure the stream is properly closed to prevent resource leaks
+		_ = stream.Close()
+	}()
+
+	// Return the channels immediately for asynchronous communication
+	// The caller can read from these channels while the goroutine processes the request
+	return dataChan, errChan
+}
+
+// SendRawTokenCount handles a token count.
+func (c *GeminiClient) SendRawTokenCount(ctx context.Context, rawJSON []byte, alt string) ([]byte, *ErrorMessage) {
+	modelResult := gjson.GetBytes(rawJSON, "model")
+	model := modelResult.String()
+	modelName := model
+	for {
+		if c.isModelQuotaExceeded(modelName) {
+			if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+				modelName = c.getPreviewModel(model)
+				if modelName != "" {
+					log.Debugf("Model %s is quota exceeded. Switch to preview model %s", model, modelName)
+					rawJSON, _ = sjson.SetBytes(rawJSON, "model", modelName)
+					continue
+				}
+			}
+			return nil, &ErrorMessage{
+				StatusCode: 429,
+				Error:      fmt.Errorf(`{"error":{"code":429,"message":"All the models of '%s' are quota exceeded","status":"RESOURCE_EXHAUSTED"}}`, model),
+			}
+		}
+
+		respBody, err := c.APIRequest(ctx, "countTokens", rawJSON, alt, false)
+		if err != nil {
+			if err.StatusCode == 429 {
+				now := time.Now()
+				c.modelQuotaExceeded[modelName] = &now
+				if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+					continue
+				}
+			}
+			return nil, err
+		}
+		delete(c.modelQuotaExceeded, modelName)
+		bodyBytes, errReadAll := io.ReadAll(respBody)
+		if errReadAll != nil {
+			return nil, &ErrorMessage{StatusCode: 500, Error: errReadAll}
+		}
+		return bodyBytes, nil
+	}
+}
+
+// SendRawMessage handles a single conversational turn, including tool calls.
+func (c *GeminiClient) SendRawMessage(ctx context.Context, rawJSON []byte, alt string) ([]byte, *ErrorMessage) {
+	if c.glAPIKey == "" {
+		rawJSON, _ = sjson.SetBytes(rawJSON, "project", c.GetProjectID())
+	}
+
+	modelResult := gjson.GetBytes(rawJSON, "model")
+	model := modelResult.String()
+	modelName := model
+	for {
+		if c.isModelQuotaExceeded(modelName) {
+			if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+				modelName = c.getPreviewModel(model)
+				if modelName != "" {
+					log.Debugf("Model %s is quota exceeded. Switch to preview model %s", model, modelName)
+					rawJSON, _ = sjson.SetBytes(rawJSON, "model", modelName)
+					continue
+				}
+			}
+			return nil, &ErrorMessage{
+				StatusCode: 429,
+				Error:      fmt.Errorf(`{"error":{"code":429,"message":"All the models of '%s' are quota exceeded","status":"RESOURCE_EXHAUSTED"}}`, model),
+			}
+		}
+
+		respBody, err := c.APIRequest(ctx, "generateContent", rawJSON, alt, false)
+		if err != nil {
+			if err.StatusCode == 429 {
+				now := time.Now()
+				c.modelQuotaExceeded[modelName] = &now
+				if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+					continue
+				}
+			}
+			return nil, err
+		}
+		delete(c.modelQuotaExceeded, modelName)
+		bodyBytes, errReadAll := io.ReadAll(respBody)
+		if errReadAll != nil {
+			return nil, &ErrorMessage{StatusCode: 500, Error: errReadAll}
+		}
+		return bodyBytes, nil
+	}
+}
+
+// SendRawMessageStream handles a single conversational turn, including tool calls.
+func (c *GeminiClient) SendRawMessageStream(ctx context.Context, rawJSON []byte, alt string) (<-chan []byte, <-chan *ErrorMessage) {
+	dataTag := []byte("data: ")
+	errChan := make(chan *ErrorMessage)
+	dataChan := make(chan []byte)
+	go func() {
+		defer close(errChan)
+		defer close(dataChan)
+
+		if c.glAPIKey == "" {
+			rawJSON, _ = sjson.SetBytes(rawJSON, "project", c.GetProjectID())
+		}
+
+		modelResult := gjson.GetBytes(rawJSON, "model")
+		model := modelResult.String()
+		modelName := model
+		var stream io.ReadCloser
+		for {
+			if c.isModelQuotaExceeded(modelName) {
+				if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+					modelName = c.getPreviewModel(model)
+					if modelName != "" {
+						log.Debugf("Model %s is quota exceeded. Switch to preview model %s", model, modelName)
+						rawJSON, _ = sjson.SetBytes(rawJSON, "model", modelName)
+						continue
+					}
+				}
+				errChan <- &ErrorMessage{
+					StatusCode: 429,
+					Error:      fmt.Errorf(`{"error":{"code":429,"message":"All the models of '%s' are quota exceeded","status":"RESOURCE_EXHAUSTED"}}`, model),
+				}
+				return
+			}
+			var err *ErrorMessage
+			stream, err = c.APIRequest(ctx, "streamGenerateContent", rawJSON, alt, true)
+			if err != nil {
+				if err.StatusCode == 429 {
+					now := time.Now()
+					c.modelQuotaExceeded[modelName] = &now
+					if c.cfg.QuotaExceeded.SwitchPreviewModel && c.glAPIKey == "" {
+						continue
+					}
+				}
+				errChan <- err
+				return
+			}
+			delete(c.modelQuotaExceeded, modelName)
+			break
+		}
+
+		if alt == "" {
+			scanner := bufio.NewScanner(stream)
+			for scanner.Scan() {
+				line := scanner.Bytes()
+				if bytes.HasPrefix(line, dataTag) {
+					dataChan <- line[6:]
+				}
+			}
+
+			if errScanner := scanner.Err(); errScanner != nil {
+				errChan <- &ErrorMessage{500, errScanner}
+				_ = stream.Close()
+				return
+			}
+
+		} else {
+			data, err := io.ReadAll(stream)
+			if err != nil {
+				errChan <- &ErrorMessage{500, err}
+				_ = stream.Close()
+				return
+			}
+			dataChan <- data
+		}
+		_ = stream.Close()
+
+	}()
+
+	return dataChan, errChan
+}
+
+// isModelQuotaExceeded checks if the specified model has exceeded its quota
+// within the last 30 minutes.
+func (c *GeminiClient) isModelQuotaExceeded(model string) bool {
+	if lastExceededTime, hasKey := c.modelQuotaExceeded[model]; hasKey {
+		duration := time.Now().Sub(*lastExceededTime)
+		if duration > 30*time.Minute {
+			return false
+		}
+		return true
+	}
+	return false
+}
+
+// getPreviewModel returns an available preview model for the given base model,
+// or an empty string if no preview models are available or all are quota exceeded.
+func (c *GeminiClient) getPreviewModel(model string) string {
+	if models, hasKey := previewModels[model]; hasKey {
+		for i := 0; i < len(models); i++ {
+			if !c.isModelQuotaExceeded(models[i]) {
+				return models[i]
+			}
+		}
+	}
+	return ""
+}
+
+// IsModelQuotaExceeded returns true if the specified model has exceeded its quota
+// and no fallback options are available.
+func (c *GeminiClient) IsModelQuotaExceeded(model string) bool {
+	if c.isModelQuotaExceeded(model) {
+		if c.cfg.QuotaExceeded.SwitchPreviewModel {
+			return c.getPreviewModel(model) == ""
+		}
+		return true
+	}
+	return false
+}
+
+// CheckCloudAPIIsEnabled sends a simple test request to the API to verify
+// that the Cloud AI API is enabled for the user's project. It provides
+// an activation URL if the API is disabled.
+func (c *GeminiClient) CheckCloudAPIIsEnabled() (bool, error) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer func() {
+		c.RequestMutex.Unlock()
+		cancel()
+	}()
+	c.RequestMutex.Lock()
+
+	// A simple request to test the API endpoint.
+	requestBody := fmt.Sprintf(`{"project":"%s","request":{"contents":[{"role":"user","parts":[{"text":"Be concise. What is the capital of France?"}]}],"generationConfig":{"thinkingConfig":{"include_thoughts":false,"thinkingBudget":0}}},"model":"gemini-2.5-flash"}`, c.tokenStorage.(*geminiAuth.GeminiTokenStorage).ProjectID)
+
+	stream, err := c.APIRequest(ctx, "streamGenerateContent", []byte(requestBody), "", true)
+	if err != nil {
+		// If a 403 Forbidden error occurs, it likely means the API is not enabled.
+		if err.StatusCode == 403 {
+			errJSON := err.Error.Error()
+			// Check for a specific error code and extract the activation URL.
+			if gjson.Get(errJSON, "0.error.code").Int() == 403 {
+				activationURL := gjson.Get(errJSON, "0.error.details.0.metadata.activationUrl").String()
+				if activationURL != "" {
+					log.Warnf(
+						"\n\nPlease activate your account with this url:\n\n%s\n\n And execute this command again:\n%s --login --project_id %s",
+						activationURL,
+						os.Args[0],
+						c.tokenStorage.(*geminiAuth.GeminiTokenStorage).ProjectID,
+					)
+				}
+			}
+			log.Warnf("\n\nPlease copy this message and create an issue.\n\n%s\n\n", errJSON)
+			return false, nil
+		}
+		return false, err.Error
+	}
+	defer func() {
+		_ = stream.Close()
+	}()
+
+	// We only need to know if the request was successful, so we can drain the stream.
+	scanner := bufio.NewScanner(stream)
+	for scanner.Scan() {
+		// Do nothing, just consume the stream.
+	}
+
+	return scanner.Err() == nil, scanner.Err()
+}
+
+// GetProjectList fetches a list of Google Cloud projects accessible by the user.
+func (c *GeminiClient) GetProjectList(ctx context.Context) (*GCPProject, error) {
+	token, err := c.httpClient.Transport.(*oauth2.Transport).Source.Token()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get token: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", "https://cloudresourcemanager.googleapis.com/v1/projects", nil)
+	if err != nil {
+		return nil, fmt.Errorf("could not create project list request: %v", err)
+	}
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token.AccessToken))
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to execute project list request: %w", err)
+	}
+	defer func() {
+		_ = resp.Body.Close()
+	}()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		bodyBytes, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("project list request failed with status %d: %s", resp.StatusCode, string(bodyBytes))
+	}
+
+	var project GCPProject
+	if err = json.NewDecoder(resp.Body).Decode(&project); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal project list: %w", err)
+	}
+	return &project, nil
+}
+
+// SaveTokenToFile serializes the client's current token storage to a JSON file.
+// The filename is constructed from the user's email and project ID.
+func (c *GeminiClient) SaveTokenToFile() error {
+	fileName := filepath.Join(c.cfg.AuthDir, fmt.Sprintf("%s-%s.json", c.tokenStorage.(*geminiAuth.GeminiTokenStorage).Email, c.tokenStorage.(*geminiAuth.GeminiTokenStorage).ProjectID))
+	log.Infof("Saving credentials to %s", fileName)
+	return c.tokenStorage.SaveTokenToFile(fileName)
+}
+
+// getClientMetadata returns a map of metadata about the client environment,
+// such as IDE type, platform, and plugin version.
+func (c *GeminiClient) getClientMetadata() map[string]string {
+	return map[string]string{
+		"ideType":    "IDE_UNSPECIFIED",
+		"platform":   "PLATFORM_UNSPECIFIED",
+		"pluginType": "GEMINI",
+		// "pluginVersion": pluginVersion,
+	}
+}
+
+// getClientMetadataString returns the client metadata as a single,
+// comma-separated string, which is required for the 'GeminiClient-Metadata' header.
+func (c *GeminiClient) getClientMetadataString() string {
+	md := c.getClientMetadata()
+	parts := make([]string, 0, len(md))
+	for k, v := range md {
+		parts = append(parts, fmt.Sprintf("%s=%s", k, v))
+	}
+	return strings.Join(parts, ",")
+}
+
+// GetUserAgent constructs the User-Agent string for HTTP requests.
+func (c *GeminiClient) GetUserAgent() string {
+	// return fmt.Sprintf("GeminiCLI/%s (%s; %s)", pluginVersion, runtime.GOOS, runtime.GOARCH)
+	return "google-api-nodejs-client/9.15.1"
+}

internal/client/models.go

@@ -1,91 +0,0 @@
-package client
-
-import "time"
-
-// ErrorMessage encapsulates an error with an associated HTTP status code.
-type ErrorMessage struct {
-	StatusCode int
-	Error      error
-}
-
-// GCPProject represents the response structure for a Google Cloud project list request.
-type GCPProject struct {
-	Projects []GCPProjectProjects `json:"projects"`
-}
-
-// GCPProjectLabels defines the labels associated with a GCP project.
-type GCPProjectLabels struct {
-	GenerativeLanguage string `json:"generative-language"`
-}
-
-// GCPProjectProjects contains details about a single Google Cloud project.
-type GCPProjectProjects struct {
-	ProjectNumber  string           `json:"projectNumber"`
-	ProjectID      string           `json:"projectId"`
-	LifecycleState string           `json:"lifecycleState"`
-	Name           string           `json:"name"`
-	Labels         GCPProjectLabels `json:"labels"`
-	CreateTime     time.Time        `json:"createTime"`
-}
-
-// Content represents a single message in a conversation, with a role and parts.
-type Content struct {
-	Role  string `json:"role"`
-	Parts []Part `json:"parts"`
-}
-
-// Part represents a distinct piece of content within a message, which can be
-// text, inline data (like an image), a function call, or a function response.
-type Part struct {
-	Text             string            `json:"text,omitempty"`
-	InlineData       *InlineData       `json:"inlineData,omitempty"`
-	FunctionCall     *FunctionCall     `json:"functionCall,omitempty"`
-	FunctionResponse *FunctionResponse `json:"functionResponse,omitempty"`
-}
-
-// InlineData represents base64-encoded data with its MIME type.
-type InlineData struct {
-	MimeType string `json:"mime_type,omitempty"`
-	Data     string `json:"data,omitempty"`
-}
-
-// FunctionCall represents a tool call requested by the model, including the
-// function name and its arguments.
-type FunctionCall struct {
-	Name string                 `json:"name"`
-	Args map[string]interface{} `json:"args"`
-}
-
-// FunctionResponse represents the result of a tool execution, sent back to the model.
-type FunctionResponse struct {
-	Name     string                 `json:"name"`
-	Response map[string]interface{} `json:"response"`
-}
-
-// GenerateContentRequest is the top-level request structure for the streamGenerateContent endpoint.
-type GenerateContentRequest struct {
-	SystemInstruction *Content          `json:"systemInstruction,omitempty"`
-	Contents          []Content         `json:"contents"`
-	Tools             []ToolDeclaration `json:"tools,omitempty"`
-	GenerationConfig  `json:"generationConfig"`
-}
-
-// GenerationConfig defines parameters that control the model's generation behavior.
-type GenerationConfig struct {
-	ThinkingConfig GenerationConfigThinkingConfig `json:"thinkingConfig,omitempty"`
-	Temperature    float64                        `json:"temperature,omitempty"`
-	TopP           float64                        `json:"topP,omitempty"`
-	TopK           float64                        `json:"topK,omitempty"`
-}
-
-// GenerationConfigThinkingConfig specifies configuration for the model's "thinking" process.
-type GenerationConfigThinkingConfig struct {
-	// IncludeThoughts determines whether the model should output its reasoning process.
-	IncludeThoughts bool `json:"include_thoughts,omitempty"`
-}
-
-// ToolDeclaration defines the structure for declaring tools (like functions)
-// that the model can call.
-type ToolDeclaration struct {
-	FunctionDeclarations []interface{} `json:"functionDeclarations"`
-}