package app

import (
	"context"
	"database/sql"
	"net/http"
	"strconv"
	"strings"
	"time"
)

const aiUsageDays = 7

func (a *App) adminAILogs(w http.ResponseWriter, r *http.Request) {
	page, size, offset := pagination(r)
	where := []string{}
	args := []any{}
	if modelID := strings.TrimSpace(r.URL.Query().Get("modelId")); modelID != "" {
		value, err := strconv.ParseInt(modelID, 10, 64)
		if err != nil {
			fail(w, http.StatusBadRequest, 20001, "模型筛选无效")
			return
		}
		where = append(where, "l.model_id=?")
		args = append(args, value)
	}
	if scene := strings.TrimSpace(r.URL.Query().Get("scene")); scene != "" {
		if !containsString([]string{"chat", "probe"}, scene) {
			fail(w, http.StatusBadRequest, 20001, "场景筛选无效")
			return
		}
		where = append(where, "l.scene=?")
		args = append(args, scene)
	}
	if status := strings.TrimSpace(r.URL.Query().Get("status")); status != "" {
		if status != "0" && status != "1" {
			fail(w, http.StatusBadRequest, 20001, "状态筛选无效")
			return
		}
		where = append(where, "l.status=?")
		args = append(args, status)
	}
	if days := strings.TrimSpace(r.URL.Query().Get("days")); days != "" {
		value, err := strconv.Atoi(days)
		if err != nil || value < 1 || value > 90 {
			fail(w, http.StatusBadRequest, 20001, "时间范围必须在 1 到 90 天之间")
			return
		}
		where = append(where, "l.created_at>=DATE_SUB(CURRENT_DATE(),INTERVAL ? DAY)")
		args = append(args, value-1)
	}
	clause := ""
	if len(where) > 0 {
		clause = " WHERE " + strings.Join(where, " AND ")
	}
	var total int
	if err := a.db.QueryRowContext(r.Context(), `SELECT COUNT(*) FROM ai_call_logs l`+clause, args...).Scan(&total); err != nil {
		fail(w, http.StatusInternalServerError, 50001, "查询调用日志失败")
		return
	}
	rows, err := a.db.QueryContext(r.Context(), `SELECT l.id,l.model_id,COALESCE(m.name,''),l.scene,l.agent_user_id,COALESCE(p.nickname,''),
		l.conversation_id,l.latency_ms,l.prompt_tokens,l.completion_tokens,l.status,l.error,l.reply_text,l.created_at
		FROM ai_call_logs l LEFT JOIN ai_models m ON m.id=l.model_id LEFT JOIN user_profiles p ON p.user_id=l.agent_user_id`+
		clause+` ORDER BY l.id DESC LIMIT ? OFFSET ?`, append(args, size, offset)...)
	if err != nil {
		fail(w, http.StatusInternalServerError, 50001, "查询调用日志失败")
		return
	}
	defer rows.Close()
	items := []map[string]any{}
	for rows.Next() {
		var id, modelID, agentUserID, conversationID int64
		var modelName, scene, nickname, errText, replyText string
		var latency, promptTokens, completionTokens, status int
		var createdAt sql.NullTime
		if rows.Scan(&id, &modelID, &modelName, &scene, &agentUserID, &nickname, &conversationID,
			&latency, &promptTokens, &completionTokens, &status, &errText, &replyText, &createdAt) != nil {
			continue
		}
		item := map[string]any{
			"id": id, "modelId": modelID, "modelName": modelName, "scene": scene,
			"agentUserId": agentUserID, "nickname": nickname, "conversationId": conversationID,
			"latencyMs": latency, "promptTokens": promptTokens, "completionTokens": completionTokens,
			"status": status, "error": errText, "reply": replyText,
		}
		if createdAt.Valid {
			item["createdAt"] = createdAt.Time.Format("2006-01-02 15:04:05")
		}
		items = append(items, item)
	}
	reply(w, map[string]any{"items": items, "page": page, "size": size, "total": total})
}

// Usage and health in one payload: the console needs both to answer "is it
// running and what is it costing".
func (a *App) adminAIUsage(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	today := map[string]any{"calls": 0, "success": 0, "failed": 0, "promptTokens": 0, "completionTokens": 0, "avgLatencyMs": 0}
	var calls, success, promptTokens, completionTokens sql.NullInt64
	// AVG() comes back as DECIMAL, which will not scan into an integer.
	var avgLatency sql.NullFloat64
	_ = a.db.QueryRowContext(ctx, `SELECT COUNT(*),SUM(status=1),SUM(prompt_tokens),SUM(completion_tokens),AVG(latency_ms)
		FROM ai_call_logs WHERE created_at>=CURRENT_DATE()`).Scan(&calls, &success, &promptTokens, &completionTokens, &avgLatency)
	today["calls"] = calls.Int64
	today["success"] = success.Int64
	today["failed"] = calls.Int64 - success.Int64
	today["promptTokens"] = promptTokens.Int64
	today["completionTokens"] = completionTokens.Int64
	today["avgLatencyMs"] = int64(avgLatency.Float64 + 0.5)

	daily := []map[string]any{}
	dailyRows, err := a.db.QueryContext(ctx, `SELECT DATE(created_at),COUNT(*),SUM(status=1),SUM(prompt_tokens+completion_tokens)
		FROM ai_call_logs WHERE created_at>=DATE_SUB(CURRENT_DATE(),INTERVAL ? DAY)
		GROUP BY DATE(created_at) ORDER BY DATE(created_at)`, aiUsageDays-1)
	if err == nil {
		defer dailyRows.Close()
		for dailyRows.Next() {
			var date sql.NullTime
			var dayCalls, daySuccess, dayTokens sql.NullInt64
			if dailyRows.Scan(&date, &dayCalls, &daySuccess, &dayTokens) != nil {
				continue
			}
			entry := map[string]any{"calls": dayCalls.Int64, "success": daySuccess.Int64, "tokens": dayTokens.Int64}
			if date.Valid {
				entry["date"] = date.Time.Format("01-02")
			}
			daily = append(daily, entry)
		}
	}

	models := []map[string]any{}
	modelRows, queryErr := a.db.QueryContext(ctx, `SELECT l.model_id,COALESCE(m.name,'已删除模型'),COUNT(*),SUM(l.status=1),
		AVG(l.latency_ms),SUM(l.prompt_tokens+l.completion_tokens)
		FROM ai_call_logs l LEFT JOIN ai_models m ON m.id=l.model_id
		WHERE l.created_at>=DATE_SUB(CURRENT_DATE(),INTERVAL ? DAY)
		GROUP BY l.model_id,m.name ORDER BY COUNT(*) DESC`, aiUsageDays-1)
	if queryErr == nil {
		defer modelRows.Close()
		for modelRows.Next() {
			var modelID sql.NullInt64
			var name string
			var modelCalls, modelSuccess, modelTokens sql.NullInt64
			var modelLatency sql.NullFloat64
			if modelRows.Scan(&modelID, &name, &modelCalls, &modelSuccess, &modelLatency, &modelTokens) != nil {
				continue
			}
			models = append(models, map[string]any{
				"modelId": modelID.Int64, "name": name, "calls": modelCalls.Int64,
				"success": modelSuccess.Int64, "avgLatencyMs": int64(modelLatency.Float64 + 0.5), "tokens": modelTokens.Int64,
			})
		}
	}

	jobs := map[string]any{"pending": 0, "running": 0, "failed24h": 0, "overdue": 0}
	var pending, running, failed, overdue int
	_ = a.db.QueryRowContext(ctx, `SELECT SUM(status=0),SUM(status=1),SUM(status=3 AND updated_at>=DATE_SUB(NOW(3),INTERVAL 1 DAY)),
		SUM(status=0 AND run_after<DATE_SUB(NOW(3),INTERVAL 60 SECOND)) FROM ai_reply_jobs`).Scan(&pending, &running, &failed, &overdue)
	jobs["pending"], jobs["running"], jobs["failed24h"], jobs["overdue"] = pending, running, failed, overdue

	recent := []map[string]any{}
	lastError := ""
	errorRows, errorQuery := a.db.QueryContext(ctx, `SELECT created_at,error FROM ai_call_logs WHERE status=0 ORDER BY id DESC LIMIT 5`)
	if errorQuery == nil {
		defer errorRows.Close()
		for errorRows.Next() {
			var createdAt sql.NullTime
			var message string
			if errorRows.Scan(&createdAt, &message) != nil {
				continue
			}
			if lastError == "" {
				lastError = message
			}
			entry := map[string]any{"message": message}
			if createdAt.Valid {
				entry["at"] = createdAt.Time.Format("2006-01-02 15:04:05")
			}
			recent = append(recent, entry)
		}
	}

	enabled := a.configBool(ctx, "ai.enabled", false)
	dailyLimit := a.configInt(ctx, "ai.daily_call_limit", 0)
	modelName, modelReady := "", true
	if model, modelErr := a.defaultAIModel(ctx); modelErr != nil {
		modelReady = false
	} else {
		modelName = model.Name
	}
	var agents, managed int
	_ = a.db.QueryRowContext(ctx, `SELECT COUNT(*),SUM(enabled=1) FROM ai_agents`).Scan(&agents, &managed)

	reply(w, map[string]any{
		"today":        today,
		"daily":        daily,
		"models":       models,
		"jobs":         jobs,
		"recentErrors": recent,
		"limits": map[string]any{
			"enabled":              enabled,
			"dailyCallLimit":       dailyLimit,
			"agentDailyReplyLimit": a.configInt(ctx, "ai.agent_daily_reply_limit", 0),
			"logRetentionDays":     a.configInt(ctx, "ai.log_retention_days", 30),
			"modelReady":           modelReady,
			"modelName":            modelName,
			"agents":               agents,
			"managedAgents":        managed,
		},
		"alerts": aiUsageAlerts(enabled, modelReady, managed, dailyLimit, int(calls.Int64), int(calls.Int64-success.Int64), overdue, lastError),
	})
}

// Alerts are computed server-side so the console and any later notifier agree
// on what counts as a problem.
func aiUsageAlerts(enabled, modelReady bool, managedAgents, dailyLimit, calls, failed, overdue int, lastError string) []map[string]string {
	alerts := []map[string]string{}
	if !enabled {
		return alerts
	}
	if !modelReady {
		alerts = append(alerts, map[string]string{"level": "error", "message": "总开关已打开，但没有可用的模型，测试账号不会回复"})
	}
	if managedAgents == 0 {
		alerts = append(alerts, map[string]string{"level": "warning", "message": "还没有账号开启托管，AI 不会回复任何会话"})
	}
	if dailyLimit > 0 {
		if calls >= dailyLimit {
			alerts = append(alerts, map[string]string{"level": "error", "message": "今日调用已达上限，后续消息不会再回复"})
		} else if calls*10 >= dailyLimit*8 {
			alerts = append(alerts, map[string]string{"level": "warning", "message": "今日调用已超过配额的 80%"})
		}
	}
	// A handful of failures is noise; a persistent failure rate is not.
	if calls >= 5 && failed*10 >= calls*3 {
		message := "今日调用失败率超过 30%"
		if lastError != "" {
			message += "，最近错误：" + lastError
		}
		alerts = append(alerts, map[string]string{"level": "error", "message": message})
	}
	if overdue > 0 {
		alerts = append(alerts, map[string]string{"level": "warning", "message": "有回复任务超过 60 秒未处理，请检查后端 worker 是否在运行"})
	}
	return alerts
}

// Call logs hold conversation replies, so they are trimmed on a schedule rather
// than kept forever. Deleting in batches keeps the lock short.
func (a *App) purgeAICallLogs(ctx context.Context) {
	days := a.configInt(ctx, "ai.log_retention_days", 30)
	if days < 1 || days > 365 {
		days = 30
	}
	for attempt := 0; attempt < 20; attempt++ {
		result, err := a.db.ExecContext(ctx, `DELETE FROM ai_call_logs WHERE created_at<DATE_SUB(NOW(3),INTERVAL ? DAY) LIMIT 1000`, days)
		if err != nil {
			return
		}
		if affected, _ := result.RowsAffected(); affected < 1000 {
			return
		}
	}
}

// Finished jobs are only useful while they are recent; the queue table stays
// small so the claiming UPDATE keeps hitting its index.
func (a *App) purgeAIReplyJobs(ctx context.Context) {
	for attempt := 0; attempt < 20; attempt++ {
		result, err := a.db.ExecContext(ctx, `DELETE FROM ai_reply_jobs WHERE status IN (2,3) AND updated_at<DATE_SUB(NOW(3),INTERVAL 7 DAY) LIMIT 1000`)
		if err != nil {
			return
		}
		if affected, _ := result.RowsAffected(); affected < 1000 {
			return
		}
	}
}

// A job left in "processing" means the process died mid-reply; returning it to
// the queue lets another worker finish it instead of stranding the reader.
func (a *App) recoverStuckAIReplyJobs(ctx context.Context) {
	_, _ = a.db.ExecContext(ctx, `UPDATE ai_reply_jobs SET status=3,last_error='处理超时，任务已中断'
		WHERE status=1 AND updated_at<DATE_SUB(NOW(3),INTERVAL 5 MINUTE)`)
}

func (a *App) runAIMaintenance(ctx context.Context) {
	ticker := time.NewTicker(time.Hour)
	defer ticker.Stop()
	// Run once at startup so a process that restarts often still trims, and so
	// the retention setting can be verified without waiting an hour.
	a.recoverStuckAIReplyJobs(ctx)
	a.purgeAICallLogs(ctx)
	a.purgeAIReplyJobs(ctx)
	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			a.recoverStuckAIReplyJobs(ctx)
			a.purgeAICallLogs(ctx)
			a.purgeAIReplyJobs(ctx)
		}
	}
}