package com.study.course_registration.seeder;

import java.time.Clock;
import java.time.DayOfWeek;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalTime;
import java.util.List;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

import com.study.course_registration.entity.Lesson;
import com.study.course_registration.entity.LessonSchedule;
import com.study.course_registration.entity.Professor;
import com.study.course_registration.entity.Semester;
import com.study.course_registration.entity.Subject;
import com.study.course_registration.entity.User;
import com.study.course_registration.enums.UserRole;
import com.study.course_registration.repository.LessonRepository;
import com.study.course_registration.repository.LessonScheduleRepository;
import com.study.course_registration.repository.ProfessorRepository;
import com.study.course_registration.repository.SemesterRepository;
import com.study.course_registration.repository.SubjectRepository;
import com.study.course_registration.repository.UserRepository;

@Component
@ConditionalOnProperty(name = "app.seed.enabled", havingValue = "true")
public class DataSeeder implements CommandLineRunner {
    public static final String SEMESTER_ID = "00000000-0000-0000-0000-000000000001";
    public static final String STUDENT_GRADE_1_ID = "30000000-0000-0000-0000-000000000001";
    public static final String STUDENT_GRADE_2_ID = "30000000-0000-0000-0000-000000000002";
    public static final String POSTGRADUATE_ID = "30000000-0000-0000-0000-000000000003";
    public static final String DATA_STRUCTURES_01_ID = "40000000-0000-0000-0000-000000000001";
    public static final String DATA_STRUCTURES_02_ID = "40000000-0000-0000-0000-000000000002";
    public static final String OVERLAP_OS_ID = "40000000-0000-0000-0000-000000000003";
    public static final String CAPACITY_ONE_ID = "40000000-0000-0000-0000-000000000004";
    public static final String MIN_GRADE_ID = "40000000-0000-0000-0000-000000000005";
    public static final String POSTGRADUATE_ONLY_ID = "40000000-0000-0000-0000-000000000006";
    public static final String BOUNDARY_LESSON_ID = "40000000-0000-0000-0000-000000000007";

    private final Clock clock;
    private final SemesterRepository semesterRepository;
    private final ProfessorRepository professorRepository;
    private final SubjectRepository subjectRepository;
    private final LessonRepository lessonRepository;
    private final LessonScheduleRepository lessonScheduleRepository;
    private final UserRepository userRepository;

    public DataSeeder(Clock clock,
                      SemesterRepository semesterRepository,
                      ProfessorRepository professorRepository,
                      SubjectRepository subjectRepository,
                      LessonRepository lessonRepository,
                      LessonScheduleRepository lessonScheduleRepository,
                      UserRepository userRepository) {
        this.clock = clock;
        this.semesterRepository = semesterRepository;
        this.professorRepository = professorRepository;
        this.subjectRepository = subjectRepository;
        this.lessonRepository = lessonRepository;
        this.lessonScheduleRepository = lessonScheduleRepository;
        this.userRepository = userRepository;
    }

    @Override
    @Transactional
    public void run(String... args) {
        if (semesterRepository.existsById(SEMESTER_ID)) {
            return;
        }

        Instant now = clock.instant();
        LocalDate today = LocalDate.now(clock);
        Semester semester = semesterRepository.save(new Semester(
                SEMESTER_ID, "2026-1", today.minusDays(30), today.plusDays(120),
                now.minusSeconds(86_400), now.plusSeconds(7 * 86_400), 18));

        List<Professor> professors = professorRepository.saveAll(List.of(
                new Professor("10000000-0000-0000-0000-000000000001", "김영한"),
                new Professor("10000000-0000-0000-0000-000000000002", "최태영"),
                new Professor("10000000-0000-0000-0000-000000000003", "조재한")));

        List<Subject> subjects = subjectRepository.saveAll(List.of(
                new Subject("20000000-0000-0000-0000-000000000001", "자바 프로그래밍", "CS201", "자바 프로그래밍 기초", 3),
                new Subject("20000000-0000-0000-0000-000000000002", "자료구조", "CS202", "자료구조 및 알고리즘", 3),
                new Subject("20000000-0000-0000-0000-000000000003", "데이터베이스", "CS203", "데이터베이스 시스템", 3),
                new Subject("20000000-0000-0000-0000-000000000004", "컴퓨터 네트워크", "CS204", "네트워크 기초", 3),
                new Subject("20000000-0000-0000-0000-000000000005", "운영체제", "CS301", "운영체제 핵심", 3),
                new Subject("20000000-0000-0000-0000-000000000006", "대학원 세미나", "CS401", "대학원 전용 세미나", 3)));

        Lesson data01 = new Lesson(DATA_STRUCTURES_01_ID, "자료구조 01분반", subjects.get(1), professors.get(0), semester, 30, null, null);
        Lesson data02 = new Lesson(DATA_STRUCTURES_02_ID, "자료구조 02분반", subjects.get(1), professors.get(1), semester, 30, null, null);
        Lesson os = new Lesson(OVERLAP_OS_ID, "운영체제", subjects.get(4), professors.get(1), semester, 30, null, null);
        Lesson capacityOne = new Lesson(CAPACITY_ONE_ID, "데이터베이스 소수정예", subjects.get(2), professors.get(2), semester, 1, null, null);
        Lesson minGrade = new Lesson(MIN_GRADE_ID, "고급 네트워크", subjects.get(3), professors.get(2), semester, 30, 3L, null);
        Lesson postgraduate = new Lesson(POSTGRADUATE_ONLY_ID, "대학원 세미나", subjects.get(5), professors.get(0), semester, 20, null, UserRole.POSTGRADUATE);
        Lesson boundary = new Lesson(BOUNDARY_LESSON_ID, "자바 프로그래밍", subjects.get(0), professors.get(0), semester, 30, null, null);
        lessonRepository.saveAll(List.of(data01, data02, os, capacityOne, minGrade, postgraduate, boundary));

        lessonScheduleRepository.saveAll(List.of(
                schedule("50000000-0000-0000-0000-000000000001", data01, DayOfWeek.MONDAY, 9, 11),
                schedule("50000000-0000-0000-0000-000000000002", data02, DayOfWeek.TUESDAY, 9, 11),
                schedule("50000000-0000-0000-0000-000000000003", os, DayOfWeek.MONDAY, 10, 12),
                schedule("50000000-0000-0000-0000-000000000004", capacityOne, DayOfWeek.WEDNESDAY, 9, 11),
                schedule("50000000-0000-0000-0000-000000000005", minGrade, DayOfWeek.THURSDAY, 9, 11),
                schedule("50000000-0000-0000-0000-000000000006", postgraduate, DayOfWeek.FRIDAY, 9, 11),
                schedule("50000000-0000-0000-0000-000000000007", boundary, DayOfWeek.MONDAY, 11, 13)));

        userRepository.saveAll(List.of(
                new User(STUDENT_GRADE_1_ID, "학생1", 1L, UserRole.STUDENT),
                new User(STUDENT_GRADE_2_ID, "학생2", 2L, UserRole.STUDENT),
                new User(POSTGRADUATE_ID, "대학원생", 3L, UserRole.POSTGRADUATE)));
    }

    private static LessonSchedule schedule(String id, Lesson lesson, DayOfWeek day, int startHour, int endHour) {
        return new LessonSchedule(id, lesson, day, LocalTime.of(startHour, 0), LocalTime.of(endHour, 0));
    }
}