package service

import (
	"context"
	"log/slog"
	"net/http"
	"time"

	"schedule_converter/auth"
	"schedule_converter/captcha"
	"schedule_converter/client"
	"schedule_converter/config"
	"schedule_converter/models"
	"schedule_converter/parser"
	apperr "schedule_converter/pkg/errors"
)

type ScheduleService struct {
	httpClient *http.Client
	maxRetries int
	retryDelay time.Duration
}

type ScheduleOption func(*ScheduleService)

func WithMaxRetries(n int) ScheduleOption {
	return func(s *ScheduleService) {
		s.maxRetries = n
	}
}

func WithRetryDelay(d time.Duration) ScheduleOption {
	return func(s *ScheduleService) {
		s.retryDelay = d
	}
}

func NewScheduleService(opts ...ScheduleOption) *ScheduleService {
	s := &ScheduleService{
		httpClient: client.Client,
		maxRetries: 3,
		retryDelay: 3 * time.Second,
	}
	for _, opt := range opts {
		opt(s)
	}
	return s
}

func NewScheduleServiceWithClient(httpClient *http.Client, opts ...ScheduleOption) *ScheduleService {
	s := &ScheduleService{
		httpClient: httpClient,
		maxRetries: 3,
		retryDelay: 3 * time.Second,
	}
	for _, opt := range opts {
		opt(s)
	}
	return s
}

func (s *ScheduleService) FetchSchedule(ctx context.Context, username, password, semester string) ([]models.Course, error) {
	log := slog.With("username", username, "semester", semester)

	if err := client.GetInitialCookiesWithClient(s.httpClient); err != nil {
		return nil, apperr.New("fetch_schedule", err, "获取Cookie失败")
	}

	var lastErr error
	for attempt := 1; attempt <= s.maxRetries; attempt++ {
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		default:
		}

		log.Info("尝试登录", "attempt", attempt, "max_retries", s.maxRetries)

		captchaCode, err := captcha.GetAndRecognize(s.httpClient)
		if err != nil {
			log.Warn("验证码获取失败", "error", err, "attempt", attempt)
			lastErr = err
			time.Sleep(s.retryDelay)
			continue
		}

		success, err := auth.LoginWithClient(s.httpClient, captchaCode, username, password)
		if err != nil {
			log.Warn("登录失败", "error", err, "attempt", attempt)
			lastErr = err
			time.Sleep(s.retryDelay)
			continue
		}

		if success {
			if semester == "" {
				semester = config.Semester
			}
			courses, err := parser.FetchScheduleWithClient(s.httpClient, semester)
			if err != nil {
				return nil, apperr.New("fetch_schedule", err, "获取课表失败")
			}
			log.Info("获取课表成功", "course_count", len(courses))
			return courses, nil
		}

		log.Warn("登录验证失败，稍后重试", "attempt", attempt)
		time.Sleep(s.retryDelay)
	}

	return nil, apperr.New("fetch_schedule", lastErr, "登录失败，已重试")
}

func (s *ScheduleService) FetchDefaultSchedule(ctx context.Context) ([]models.Course, error) {
	return s.FetchSchedule(ctx, config.Username, config.Password, config.Semester)
}

func (s *ScheduleService) FetchScheduleForUser(username, password, semester string) ([]models.Course, error) {
	return s.FetchSchedule(context.Background(), username, password, semester)
}

func (s *ScheduleService) FetchDefaultScheduleLegacy() ([]models.Course, error) {
	return s.FetchScheduleForUser(config.Username, config.Password, config.Semester)
}