package grpc

import (
	"context"
	"encoding/json"
	"log/slog"

	pb "schedule_converter/proto/runner"

	"schedule_converter/config"
	"schedule_converter/parser"
	apperr "schedule_converter/pkg/errors"
)

func (h *TaskHandler) getEmptyClassrooms(ctx context.Context, payload []byte) ([]byte, error) {
	var req pb.GetEmptyClassroomPayload
	if err := unmarshalPayload(payload, &req); err != nil {
		return nil, err
	}

	log := slog.With("username", req.Username, "semester", req.Semester)
	log.Info("获取空教室任务")

	httpClient, err := createHTTPClient()
	if err != nil {
		return nil, err
	}

	cfg := config.Get()
	setTWFIDCookie(httpClient, cfg.BaseURL, "")

	if err := executeLogin(ctx, httpClient, req.Username, req.Password); err != nil {
		return nil, err
	}

	classrooms, err := parser.FetchEmptyClassrooms(httpClient, req.Semester, req.WeekStart, req.WeekEnd, req.CampusCode)
	if err != nil {
		return nil, apperr.New("fetch_empty_classrooms", err, "获取空教室失败")
	}

	pbClassrooms := convertEmptyClassrooms(classrooms)

	result := &pb.EmptyClassroomResultData{
		StudentId:  req.Username,
		Semester:   req.Semester,
		Classrooms: pbClassrooms,
	}

	log.Info("空教室获取成功", "classroom_count", len(pbClassrooms))
	return json.Marshal(result)
}