// Package handler provides HTTP handlers for various endpoints.
package handler

import (
	"net/http"
	"strings"

	"modelRT/config"
	"modelRT/database"
	"modelRT/logger"
	"modelRT/network"
	"modelRT/orm"
	"modelRT/task"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

// AsyncTaskCreateHandler handles creation of asynchronous tasks
// @Summary 创建异步任务
// @Description 创建新的异步任务并返回任务ID，任务将被提交到队列等待处理
// @Tags AsyncTask
// @Accept json
// @Produce json
// @Param request body network.AsyncTaskCreateRequest true "任务创建请求"
// @Success 200 {object} network.SuccessResponse{payload=network.AsyncTaskCreateResponse} "任务创建成功"
// @Failure 400 {object} network.FailureResponse "请求参数错误"
// @Failure 500 {object} network.FailureResponse "服务器内部错误"
// @Router /task/async [post]
func AsyncTaskCreateHandler(c *gin.Context) {
	ctx := c.Request.Context()
	var request network.AsyncTaskCreateRequest

	if err := c.ShouldBindJSON(&request); err != nil {
		logger.Error(ctx, "failed to unmarshal async task create request", "error", err)
		c.JSON(http.StatusOK, network.FailureResponse{
			Code: http.StatusBadRequest,
			Msg:  "invalid request parameters",
		})
		return
	}

	// Validate task type
	if !orm.IsValidAsyncTaskType(request.TaskType) {
		logger.Error(ctx, "invalid task type", "task_type", request.TaskType)
		c.JSON(http.StatusOK, network.FailureResponse{
			Code: http.StatusBadRequest,
			Msg:  "invalid task type",
		})
		return
	}

	// Validate task parameters based on task type
	if !validateTaskParams(request.TaskType, request.Params) {
		logger.Error(ctx, "invalid task parameters", "task_type", request.TaskType, "params", request.Params)
		c.JSON(http.StatusOK, network.FailureResponse{
			Code: http.StatusBadRequest,
			Msg:  "invalid task parameters",
		})
		return
	}

	pgClient := database.GetPostgresDBClient()
	if pgClient == nil {
		logger.Error(ctx, "database connection not found in context")
		c.JSON(http.StatusOK, network.FailureResponse{
			Code: http.StatusInternalServerError,
			Msg:  "database connection error",
		})
		return
	}

	// Create task in database
	taskType := orm.AsyncTaskType(request.TaskType)
	params := orm.JSONMap(request.Params)

	asyncTask, err := database.CreateAsyncTask(ctx, pgClient, taskType, params)
	if err != nil {
		logger.Error(ctx, "failed to create async task in database", "error", err)
		c.JSON(http.StatusOK, network.FailureResponse{
			Code: http.StatusInternalServerError,
			Msg:  "failed to create task",
		})
		return
	}

	// Send task to message queue
	cfg, exists := c.Get("config")
	if !exists {
		logger.Warn(ctx, "Configuration not found in context, skipping queue publishing")
	} else {
		modelRTConfig := cfg.(config.ModelRTConfig)
		ctx := c.Request.Context()

		// Create queue producer
		producer, err := task.NewQueueProducer(ctx, modelRTConfig.RabbitMQConfig)
		if err != nil {
			logger.Error(ctx, "Failed to create queue producer", "error", err)
			// Continue without queue publishing
		} else {
			defer producer.Close()

			// Publish task to queue
			taskType := task.TaskType(request.TaskType)
			priority := 5 // Default priority

			if err := producer.PublishTaskWithRetry(ctx, asyncTask.TaskID, taskType, priority, 3); err != nil {
				logger.Error(ctx, "Failed to publish task to queue",
					"task_id", asyncTask.TaskID,
					"error", err)
				// Log error but don't affect task creation response
			} else {
				logger.Info(ctx, "Task published to queue successfully",
					"task_id", asyncTask.TaskID,
					"queue", task.TaskQueueName)
			}
		}
	}

	logger.Info(ctx, "async task created successfully", "task_id", asyncTask.TaskID, "task_type", request.TaskType)

	// Return success response
	c.JSON(http.StatusOK, network.SuccessResponse{
		Code: 2000,
		Msg:  "task created successfully",
		Payload: network.AsyncTaskCreateResponse{
			TaskID: asyncTask.TaskID,
		},
	})
}

func validateTaskParams(taskType string, params map[string]any) bool {
	switch taskType {
	case string(orm.AsyncTaskTypeTopologyAnalysis):
		return validateTopologyAnalysisParams(params)
	case string(orm.AsyncTaskTypePerformanceAnalysis):
		return validatePerformanceAnalysisParams(params)
	case string(orm.AsyncTaskTypeEventAnalysis):
		return validateEventAnalysisParams(params)
	case string(orm.AsyncTaskTypeBatchImport):
		return validateBatchImportParams(params)
	case string(orm.AsyncTaskTypeTest):
		return validateTestTaskParams(params)
	default:
		return false
	}
}

func validateTopologyAnalysisParams(params map[string]any) bool {
	// Check required parameters for topology analysis
	if startUUID, ok := params["start_uuid"]; !ok || startUUID == "" {
		return false
	}
	if endUUID, ok := params["end_uuid"]; !ok || endUUID == "" {
		return false
	}
	return true
}

func validatePerformanceAnalysisParams(params map[string]any) bool {
	// Check required parameters for performance analysis
	if componentIDs, ok := params["component_ids"]; !ok {
		return false
	} else if ids, isSlice := componentIDs.([]interface{}); !isSlice || len(ids) == 0 {
		return false
	}
	return true
}

func validateEventAnalysisParams(params map[string]any) bool {
	// Check required parameters for event analysis
	if eventType, ok := params["event_type"]; !ok || eventType == "" {
		return false
	}
	return true
}

func validateBatchImportParams(params map[string]any) bool {
	// Check required parameters for batch import
	if filePath, ok := params["file_path"]; !ok || filePath == "" {
		return false
	}
	return true
}

func validateTestTaskParams(params map[string]any) bool {
	// Test task has optional parameters, all are valid
	// sleep_duration defaults to 60 seconds if not provided
	return true
}

func splitCommaSeparated(s string) []string {
	var result []string
	var current strings.Builder
	inQuotes := false
	escape := false

	for _, ch := range s {
		if escape {
			current.WriteRune(ch)
			escape = false
			continue
		}

		switch ch {
		case '\\':
			escape = true
		case '"':
			inQuotes = !inQuotes
		case ',':
			if !inQuotes {
				result = append(result, strings.TrimSpace(current.String()))
				current.Reset()
			} else {
				current.WriteRune(ch)
			}
		default:
			current.WriteRune(ch)
		}
	}

	if current.Len() > 0 {
		result = append(result, strings.TrimSpace(current.String()))
	}

	return result
}

func getDBFromContext(c *gin.Context) *gorm.DB {
	// Try to get database connection from context
	// This should be set by middleware
	if db, exists := c.Get("db"); exists {
		if gormDB, ok := db.(*gorm.DB); ok {
			return gormDB
		}
	}

	// Fallback to global database connection
	// This should be implemented based on your application's database setup
	// For now, return nil - actual implementation should retrieve from application context
	return nil
}