package parser

import (
	"strings"

	"schedule_converter/models"

	"github.com/PuerkitoBio/goquery"
)

// examTypeToCode 将考试类型映射为教务系统的请求码。
func examTypeToCode(t models.ExamType) string {
	switch t {
	case models.ExamTypeMidterm:
		return "02"
	case models.ExamTypeMakeup:
		return "03"
	default:
		return "01"
	}
}

// ExamTypeCode 返回考试类型对应的请求码（供 client 层构造请求使用）。
func ExamTypeCode(t models.ExamType) string {
	return examTypeToCode(t)
}

// ParseExamHTML 解析考试安排页面 HTML，返回考试条目列表。
func ParseExamHTML(html string, examType models.ExamType) ([]models.ExamEntry, error) {
	doc, err := goquery.NewDocumentFromReader(strings.NewReader(html))
	if err != nil {
		return nil, err
	}

	var exams []models.ExamEntry

	doc.Find("table.bot_line").Each(func(_ int, table *goquery.Selection) {
		rows := table.Find("tr")
		if rows.Length() < 2 {
			return
		}

		rows.Each(func(idx int, row *goquery.Selection) {
			if idx == 0 {
				return
			}
			cells := row.Find("td")
			if cells.Length() < 6 {
				return
			}

			texts := getCellTexts(cells)

			exam := models.ExamEntry{
				Course:  safeGet(texts, 1),
				Date:    safeGet(texts, 2),
				Time:    safeGet(texts, 3),
				Week:    safeGet(texts, 4),
				Weekday: safeGet(texts, 5),
				Type:    examType,
			}

			if exam.Course != "" && len(exam.Course) >= 2 {
				exams = append(exams, exam)
			}
		})
	})

	return exams, nil
}