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

import (
	"modelRT/constants"
	"modelRT/database"
	"modelRT/logger"
	"modelRT/network"
	"modelRT/orm"
	"modelRT/task"

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

// 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, "unmarshal async task create request failed", "error", err)
		renderRespFailure(c, constants.RespCodeInvalidParams, "invalid request parameters", nil)
		return
	}

	// validate task type
	if !orm.IsValidAsyncTaskType(request.TaskType) {
		logger.Error(ctx, "check task type invalid", "task_type", request.TaskType)
		renderRespFailure(c, constants.RespCodeInvalidParams, "invalid task type", nil)
		return
	}

	// validate task parameters based on task type
	if !validateTaskParams(request.TaskType, request.Params) {
		logger.Error(ctx, "check task parameters invalid", "task_type", request.TaskType, "params", request.Params)
		renderRespFailure(c, constants.RespCodeInvalidParams, "invalid task parameters", nil)
		return
	}

	pgClient := database.GetPostgresDBClient()
	if pgClient == nil {
		logger.Error(ctx, "database connection not found in context")
		renderRespFailure(c, constants.RespCodeServerError, "database connection error", nil)
		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, "create async task in database failed", "error", err)
		renderRespFailure(c, constants.RespCodeServerError, "failed to create task", nil)
		return
	}

	// enqueue task to channel for async publishing to RabbitMQ
	msg := task.NewTaskQueueMessageWithPriority(asyncTask.TaskID, task.TaskType(request.TaskType), 5)
	// propagate HTTP request trace so the async chain stays on the same traceID
	if v, _ := ctx.Value(constants.CtxKeyTraceID).(string); v != "" {
		msg.TraceID = v
	}
	if v, _ := ctx.Value(constants.CtxKeySpanID).(string); v != "" {
		msg.SpanID = v
	}
	task.TaskMsgChan <- msg
	logger.Info(ctx, "task enqueued to channel", "task_id", asyncTask.TaskID, "queue", constants.TaskQueueName)

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

	// return success response
	payload := genAsyncTaskCreatePayload(asyncTask.TaskID.String())
	renderRespSuccess(c, constants.RespCodeSuccess, "task created successfully", payload)
}

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 genAsyncTaskCreatePayload(taskID string) map[string]any {
	payload := map[string]any{
		"task_id": taskID,
	}
	return payload
}