package repository

import (
	"context"
	"fmt"
	"time"

	"cpa-ext/internal/collection"
)

func (r *SQLiteUsageRepository) UsageDashboard(ctx context.Context, today time.Time, days int) (collection.UsageDashboard, error) {
	if days < 1 {
		days = 7
	}
	start := time.Date(today.Year(), today.Month(), today.Day(), 0, 0, 0, 0, today.Location())
	dashboard := collection.UsageDashboard{}
	if err := r.db.QueryRowContext(ctx, `
SELECT COUNT(*), COALESCE(SUM(u.input_tokens),0), COALESCE(SUM(u.output_tokens),0),
       COALESCE(SUM(u.total_tokens),0), COALESCE(SUM(u.cost_micros),0)
FROM request_detail_index d LEFT JOIN usage_records u ON u.id=d.usage_id
WHERE d.requested_at>=?`, formatTime(start)).Scan(&dashboard.Today.Requests, &dashboard.Today.InputTokens, &dashboard.Today.OutputTokens, &dashboard.Today.TotalTokens, &dashboard.Today.CostMicros); err != nil {
		return dashboard, fmt.Errorf("汇总今日用量: %w", err)
	}
	rows, err := r.db.QueryContext(ctx, `
SELECT d.managed_key_id, COALESCE(k.name, '未识别'),
       SUM(CASE WHEN d.requested_at>=? THEN 1 ELSE 0 END),
       COALESCE(SUM(CASE WHEN d.requested_at>=? THEN u.input_tokens ELSE 0 END),0),
       COALESCE(SUM(CASE WHEN d.requested_at>=? THEN u.output_tokens ELSE 0 END),0),
       COALESCE(SUM(CASE WHEN d.requested_at>=? THEN u.total_tokens ELSE 0 END),0),
       COALESCE(SUM(CASE WHEN d.requested_at>=? THEN u.cost_micros ELSE 0 END),0),
       MAX(d.requested_at)
FROM request_detail_index d
LEFT JOIN usage_records u ON u.id=d.usage_id
LEFT JOIN managed_keys k ON k.id=d.managed_key_id
GROUP BY d.managed_key_id, COALESCE(k.name, '未识别')
ORDER BY 6 DESC, 2`, formatTime(start), formatTime(start), formatTime(start), formatTime(start), formatTime(start))
	if err != nil {
		return dashboard, fmt.Errorf("汇总用户用量: %w", err)
	}
	for rows.Next() {
		var item collection.UserUsageSummary
		var last string
		if err := rows.Scan(&item.KeyID, &item.KeyAlias, &item.Today.Requests, &item.Today.InputTokens, &item.Today.OutputTokens, &item.Today.TotalTokens, &item.Today.CostMicros, &last); err != nil {
			_ = rows.Close()
			return dashboard, fmt.Errorf("读取用户用量汇总: %w", err)
		}
		if parsed, parseErr := time.Parse(time.RFC3339Nano, last); parseErr == nil {
			item.LastUsedAt = &parsed
		}
		dashboard.Users = append(dashboard.Users, item)
	}
	_ = rows.Close()

	dailyStart := start.AddDate(0, 0, -(days - 1))
	rows, err = r.db.QueryContext(ctx, `
SELECT DATE(d.requested_at, '+8 hours'), COALESCE(SUM(u.total_tokens),0)
FROM request_detail_index d LEFT JOIN usage_records u ON u.id=d.usage_id
WHERE d.requested_at>=? GROUP BY DATE(d.requested_at, '+8 hours') ORDER BY 1`, formatTime(dailyStart))
	if err != nil {
		return dashboard, fmt.Errorf("汇总每日用量: %w", err)
	}
	byDate := make(map[string]int64)
	for rows.Next() {
		var date string
		var tokens int64
		if err := rows.Scan(&date, &tokens); err != nil {
			_ = rows.Close()
			return dashboard, fmt.Errorf("读取每日用量: %w", err)
		}
		byDate[date] = tokens
	}
	_ = rows.Close()
	for index := 0; index < days; index++ {
		date := dailyStart.AddDate(0, 0, index)
		dashboard.Days = append(dashboard.Days, collection.DailyUsageSummary{Date: date, TotalTokens: byDate[date.Format("2006-01-02")]})
	}
	return dashboard, nil
}