package task

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"sync"
	"time"

	"github.com/redis/go-redis/v9"
	"gorm.io/gorm"

	"spider/internal/model"
	"spider/internal/plugin"
	"spider/internal/processor"
	"spider/internal/store"
)

// StartRequest is the payload for starting a new task.
type StartRequest struct {
	PluginName string `json:"plugin_name" binding:"required"`
	AutoClean  bool   `json:"auto_clean"` // run processor after collection (default true)
}

// Manager manages plugin task lifecycle using goroutines.
// Replaces the asynq-based worker.
type Manager struct {
	db        *gorm.DB
	redis     *redis.Client
	registry  *plugin.Registry
	store     *store.Store
	processor *processor.Processor

	mu       sync.Mutex
	running  map[uint]context.CancelFunc // taskID -> cancel
}

// NewManager creates a new task manager.
func NewManager(db *gorm.DB, rdb *redis.Client, reg *plugin.Registry, s *store.Store, proc *processor.Processor) *Manager {
	return &Manager{
		db:        db,
		redis:     rdb,
		registry:  reg,
		store:     s,
		processor: proc,
		running:   make(map[uint]context.CancelFunc),
	}
}

// StartTask validates, creates a TaskLog record, and runs the plugin in a goroutine.
func (m *Manager) StartTask(req StartRequest) (*model.TaskLog, error) {
	// Validate plugin exists
	collector, err := m.registry.Get(req.PluginName)
	if err != nil {
		return nil, fmt.Errorf("unknown plugin: %s", req.PluginName)
	}

	// Check if same plugin is already running
	var count int64
	m.db.Model(&model.TaskLog{}).
		Where("plugin_name = ? AND status = ?", req.PluginName, "running").
		Count(&count)
	if count > 0 {
		return nil, fmt.Errorf("plugin %s is already running", req.PluginName)
	}

	// Create task log record
	now := time.Now()
	taskLog := &model.TaskLog{
		TaskType:   "collect",
		PluginName: req.PluginName,
		Status:     "running",
		StartedAt:  &now,
	}
	if err := m.db.Create(taskLog).Error; err != nil {
		return nil, fmt.Errorf("create task log: %w", err)
	}

	// Build config for the plugin
	cfg, err := m.buildPluginConfig(req.PluginName)
	if err != nil {
		m.failTask(taskLog, err)
		return nil, err
	}

	// Start in goroutine
	ctx, cancel := context.WithCancel(context.Background())

	m.mu.Lock()
	m.running[taskLog.ID] = cancel
	m.mu.Unlock()

	autoClean := req.AutoClean
	// Default to true if not explicitly set
	if !req.AutoClean {
		autoClean = true
	}

	go m.runTask(ctx, taskLog, collector, cfg, autoClean)

	return taskLog, nil
}

func (m *Manager) runTask(ctx context.Context, taskLog *model.TaskLog, collector plugin.Collector, cfg map[string]any, autoClean bool) {
	defer func() {
		m.mu.Lock()
		delete(m.running, taskLog.ID)
		m.mu.Unlock()
	}()

	m.writeLog(ctx, taskLog.ID, fmt.Sprintf("开始采集: %s", collector.Name()))

	merchantCount := 0
	errCount := 0

	// Callback: for each merchant found, save to raw table
	callback := func(data plugin.MerchantData) {
		inserted, err := m.store.SaveRaw(data)
		if err != nil {
			errCount++
			log.Printf("[task] save raw error: %v", err)
			return
		}
		if inserted {
			merchantCount++
			if merchantCount%10 == 0 {
				m.writeProgress(ctx, taskLog.ID, collector.Name(), merchantCount, 0,
					fmt.Sprintf("已采集 %d 个商户", merchantCount))
			}
		}
	}

	// Run the collector
	runErr := collector.Run(ctx, cfg, callback)

	// Check if stopped
	if m.isStopRequested(ctx, taskLog.ID) || ctx.Err() != nil {
		m.writeLog(ctx, taskLog.ID, "任务已停止")
		finishedAt := time.Now()
		m.db.Model(taskLog).Updates(map[string]any{
			"status":          "stopped",
			"finished_at":     &finishedAt,
			"merchants_added": merchantCount,
			"errors_count":    errCount,
		})
		return
	}

	if runErr != nil {
		m.failTask(taskLog, runErr)
		m.writeLog(ctx, taskLog.ID, "采集失败: "+runErr.Error())
		return
	}

	m.writeLog(ctx, taskLog.ID, fmt.Sprintf("采集完成: 新增 %d 个商户", merchantCount))

	// Auto-clean: run processor on new raw records
	if autoClean && merchantCount > 0 {
		m.writeLog(ctx, taskLog.ID, "开始清洗流程...")
		m.writeProgress(ctx, taskLog.ID, "clean", 0, 0, "清洗中...")

		m.processor.SetProgressFn(func(step string, current, total int, msg string) {
			m.writeProgress(ctx, taskLog.ID, step, current, total, msg)
			m.writeLog(ctx, taskLog.ID, fmt.Sprintf("[%s] %d/%d %s", step, current, total, msg))
		})

		procResult, procErr := m.processor.Process(ctx)
		if procErr != nil {
			m.writeLog(ctx, taskLog.ID, "清洗失败: "+procErr.Error())
		} else {
			m.writeLog(ctx, taskLog.ID, fmt.Sprintf("清洗完成: Hot=%d, Warm=%d, Cold=%d",
				procResult.HotCount, procResult.WarmCount, procResult.ColdCount))
		}
	}

	// Complete
	finishedAt := time.Now()
	detail := fmt.Sprintf("采集 %d 个商户, 错误 %d 次", merchantCount, errCount)
	m.db.Model(taskLog).Updates(map[string]any{
		"status":          "completed",
		"finished_at":     &finishedAt,
		"merchants_added": merchantCount,
		"errors_count":    errCount,
		"detail":          detail,
	})

	m.writeProgress(ctx, taskLog.ID, "done", 100, 100, "任务完成")
	m.writeLog(ctx, taskLog.ID, "任务完成")
	log.Printf("[task] task %d completed: %s", taskLog.ID, detail)
}

// StartClean runs the processor independently (not tied to a plugin).
func (m *Manager) StartClean() (*model.TaskLog, error) {
	var count int64
	m.db.Model(&model.TaskLog{}).
		Where("task_type = ? AND status = ?", "clean", "running").
		Count(&count)
	if count > 0 {
		return nil, fmt.Errorf("clean task is already running")
	}

	now := time.Now()
	taskLog := &model.TaskLog{
		TaskType:   "clean",
		PluginName: "",
		Status:     "running",
		StartedAt:  &now,
	}
	if err := m.db.Create(taskLog).Error; err != nil {
		return nil, err
	}

	ctx, cancel := context.WithCancel(context.Background())
	m.mu.Lock()
	m.running[taskLog.ID] = cancel
	m.mu.Unlock()

	go func() {
		defer func() {
			m.mu.Lock()
			delete(m.running, taskLog.ID)
			m.mu.Unlock()
		}()

		m.writeLog(ctx, taskLog.ID, "开始独立清洗任务")

		m.processor.SetProgressFn(func(step string, current, total int, msg string) {
			m.writeProgress(ctx, taskLog.ID, step, current, total, msg)
		})

		result, err := m.processor.Process(ctx)

		finishedAt := time.Now()
		if err != nil {
			m.db.Model(taskLog).Updates(map[string]any{
				"status":      "failed",
				"finished_at": &finishedAt,
				"detail":      err.Error(),
			})
			return
		}

		detail := fmt.Sprintf("输入 %d, Hot=%d, Warm=%d, Cold=%d",
			result.InputCount, result.HotCount, result.WarmCount, result.ColdCount)
		m.db.Model(taskLog).Updates(map[string]any{
			"status":          "completed",
			"finished_at":     &finishedAt,
			"items_processed": result.InputCount,
			"merchants_added": result.OutputCount,
			"detail":          detail,
		})

		m.writeLog(ctx, taskLog.ID, "清洗完成: "+detail)
	}()

	return taskLog, nil
}

// StopTask cancels a running task.
func (m *Manager) StopTask(taskID uint) error {
	// Set Redis stop signal
	key := fmt.Sprintf("spider:task:stop:%d", taskID)
	m.redis.Set(context.Background(), key, "1", time.Hour)

	// Cancel the goroutine context
	m.mu.Lock()
	cancel, ok := m.running[taskID]
	m.mu.Unlock()

	if ok {
		cancel()
	}

	// Also try to stop the collector
	var taskLog model.TaskLog
	if err := m.db.First(&taskLog, taskID).Error; err == nil && taskLog.PluginName != "" {
		if collector, err := m.registry.Get(taskLog.PluginName); err == nil {
			collector.Stop()
		}
	}

	return nil
}

// GetProgress reads live progress from Redis.
func (m *Manager) GetProgress(taskID uint) map[string]any {
	key := fmt.Sprintf("spider:task:progress:%d", taskID)
	vals, err := m.redis.HGetAll(context.Background(), key).Result()
	if err != nil {
		return nil
	}
	result := make(map[string]any)
	for k, v := range vals {
		result[k] = v
	}
	return result
}

// GetLogs reads task logs from Redis.
func (m *Manager) GetLogs(taskID uint) []string {
	key := fmt.Sprintf("spider:task:logs:%d", taskID)
	logs, err := m.redis.LRange(context.Background(), key, 0, -1).Result()
	if err != nil {
		return nil
	}
	return logs
}

// buildPluginConfig builds the config map for a plugin from the DB.
func (m *Manager) buildPluginConfig(pluginName string) (map[string]any, error) {
	cfg := make(map[string]any)

	switch pluginName {
	case "web_collector":
		keywords, err := m.store.ListEnabledKeywords()
		if err != nil {
			return nil, err
		}
		kws := make([]string, 0, len(keywords))
		for _, k := range keywords {
			kws = append(kws, k.Keyword)
		}
		cfg["keywords"] = kws

	case "tg_collector":
		seeds, err := m.store.ListSeeds()
		if err != nil {
			return nil, err
		}
		seedNames := make([]string, 0, len(seeds))
		for _, s := range seeds {
			seedNames = append(seedNames, s.Keyword)
		}
		cfg["seeds"] = seedNames
		cfg["max_depth"] = 3
		cfg["max_channels"] = 500
		cfg["message_limit"] = 500

	case "github_collector":
		keywords, err := m.store.ListEnabledKeywords()
		if err != nil {
			return nil, err
		}
		kws := make([]string, 0, len(keywords))
		for _, k := range keywords {
			kws = append(kws, k.Keyword)
		}
		cfg["keywords"] = kws
		cfg["repos_limit"] = 50
	}

	return cfg, nil
}

func (m *Manager) failTask(taskLog *model.TaskLog, err error) {
	finishedAt := time.Now()
	m.db.Model(taskLog).Updates(map[string]any{
		"status":      "failed",
		"finished_at": &finishedAt,
		"detail":      err.Error(),
	})
}

func (m *Manager) isStopRequested(ctx context.Context, taskID uint) bool {
	key := fmt.Sprintf("spider:task:stop:%d", taskID)
	val, _ := m.redis.Get(ctx, key).Result()
	return val == "1"
}

func (m *Manager) writeLog(ctx context.Context, taskID uint, msg string) {
	key := fmt.Sprintf("spider:task:logs:%d", taskID)
	ts := time.Now().Format("15:04:05")
	line := fmt.Sprintf("[%s] %s", ts, msg)
	m.redis.RPush(ctx, key, line)
	m.redis.LTrim(ctx, key, -500, -1)
	m.redis.Expire(ctx, key, 24*time.Hour)
}

func (m *Manager) writeProgress(ctx context.Context, taskID uint, phase string, current, total int, message string) {
	key := fmt.Sprintf("spider:task:progress:%d", taskID)
	now := time.Now().UTC().Format(time.RFC3339)
	fields := map[string]any{
		"phase":      phase,
		"current":    current,
		"total":      total,
		"message":    message,
		"updated_at": now,
	}
	b, _ := json.Marshal(fields)
	m.redis.Set(ctx, key, string(b), 24*time.Hour)
}