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

import (
	"time"

	"modelRT/constants"
	"modelRT/database"
	"modelRT/logger"
	"modelRT/orm"

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

// AsyncTaskCancelHandler handles cancellation of an async task
// @Summary 取消异步任务
// @Description 取消指定ID的异步任务（如果任务尚未开始执行）
// @Tags AsyncTask
// @Accept json
// @Produce json
// @Param task_id path string true "任务ID"
// @Success 200 {object} network.SuccessResponse "任务取消成功"
// @Failure 200 {object} network.FailureResponse "请求参数错误或任务无法取消"
// @Router /task/async/{task_id}/cancel [post]
func AsyncTaskCancelHandler(c *gin.Context) {
	ctx := c.Request.Context()

	taskIDStr := c.Param("task_id")
	if taskIDStr == "" {
		logger.Error(ctx, "task_id parameter is required")
		renderRespFailure(c, constants.RespCodeInvalidParams, "task_id parameter is required", nil)
		return
	}

	taskID, err := uuid.FromString(taskIDStr)
	if err != nil {
		logger.Error(ctx, "invalid task ID format", "task_id", taskIDStr, "error", err)
		renderRespFailure(c, constants.RespCodeInvalidParams, "invalid task ID format", 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
	}

	asyncTask, err := database.GetAsyncTaskByID(ctx, pgClient, taskID)
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			logger.Error(ctx, "async task not found", "task_id", taskID)
			renderRespFailure(c, constants.RespCodeInvalidParams, "task not found", nil)
			return
		}
		logger.Error(ctx, "failed to query async task from database", "error", err)
		renderRespFailure(c, constants.RespCodeServerError, "failed to query task", nil)
		return
	}

	if asyncTask.Status != orm.AsyncTaskStatusSubmitted {
		logger.Error(ctx, "task cannot be cancelled", "task_id", taskID, "status", asyncTask.Status)
		renderRespFailure(c, constants.RespCodeInvalidParams, "task cannot be cancelled, already running or completed", nil)
		return
	}

	timestamp := time.Now().Unix()
	err = database.FailAsyncTask(ctx, pgClient, taskID, timestamp)
	if err != nil {
		logger.Error(ctx, "failed to cancel async task", "task_id", taskID, "error", err)
		renderRespFailure(c, constants.RespCodeServerError, "failed to cancel task", nil)
		return
	}

	err = database.UpdateAsyncTaskResultWithError(ctx, pgClient, taskID, 40009, "task cancelled by user", orm.JSONMap{
		"cancelled_at": timestamp,
		"cancelled_by": "user",
	})
	if err != nil {
		logger.Error(ctx, "failed to update task result with cancellation error", "task_id", taskID, "error", err)
	}

	renderRespSuccess(c, constants.RespCodeSuccess, "task cancelled successfully", nil)
}