package handler

import (
	"context"
	"strings"

	"gcy_hpc_server/internal/model"
	"gcy_hpc_server/internal/server"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

type taskServiceProvider interface {
	SubmitAsync(ctx context.Context, req *model.CreateTaskRequest) (int64, error)
	ListTasks(ctx context.Context, query *model.TaskListQuery) ([]model.Task, int64, error)
}

type TaskHandler struct {
	svc    taskServiceProvider
	logger *zap.Logger
}

func NewTaskHandler(svc taskServiceProvider, logger *zap.Logger) *TaskHandler {
	return &TaskHandler{svc: svc, logger: logger}
}

func (h *TaskHandler) CreateTask(c *gin.Context) {
	var req model.CreateTaskRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		h.logger.Warn("invalid request body for create task", zap.Error(err))
		server.BadRequest(c, err.Error())
		return
	}

	taskID, err := h.svc.SubmitAsync(c.Request.Context(), &req)
	if err != nil {
		errStr := err.Error()
		if strings.Contains(errStr, "not found") {
			h.logger.Warn("task submit target not found", zap.Error(err))
			server.NotFound(c, errStr)
			return
		}
		if strings.Contains(errStr, "exceeds limit") || strings.Contains(errStr, "validation") {
			h.logger.Warn("task submit validation failed", zap.Error(err))
			server.BadRequest(c, errStr)
			return
		}
		h.logger.Error("failed to create task", zap.Error(err))
		server.InternalError(c, errStr)
		return
	}

	h.logger.Info("task created", zap.Int64("id", taskID))
	server.Created(c, gin.H{"id": taskID})
}

func (h *TaskHandler) ListTasks(c *gin.Context) {
	var query model.TaskListQuery
	_ = c.ShouldBindQuery(&query)

	if query.Page < 1 {
		query.Page = 1
	}
	if query.PageSize < 1 || query.PageSize > 100 {
		query.PageSize = 10
	}

	tasks, total, err := h.svc.ListTasks(c.Request.Context(), &query)
	if err != nil {
		h.logger.Error("failed to list tasks", zap.Error(err))
		server.InternalError(c, err.Error())
		return
	}

	responses := make([]model.TaskResponse, 0, len(tasks))
	for i := range tasks {
		responses = append(responses, model.TaskResponse{
			ID:           tasks[i].ID,
			TaskName:     tasks[i].TaskName,
			AppID:        tasks[i].AppID,
			AppName:      tasks[i].AppName,
			Status:       tasks[i].Status,
			CurrentStep:  tasks[i].CurrentStep,
			RetryCount:   tasks[i].RetryCount,
			SlurmJobID:   tasks[i].SlurmJobID,
			WorkDir:      tasks[i].WorkDir,
			ErrorMessage: tasks[i].ErrorMessage,
			CreatedAt:    tasks[i].CreatedAt,
			UpdatedAt:    tasks[i].UpdatedAt,
		})
	}

	server.OK(c, model.TaskListResponse{
		Items: responses,
		Total: total,
	})
}