'use server';

import { revalidatePath } from 'next/cache';
import { redirect } from 'next/navigation';
import { verifySession } from '@/lib/auth/dal';
import { uploadAttachment } from '@/lib/data/repositories/file-repository';
import {
  buildComicPayload,
  buildShortsPayload,
  createContent,
  deleteContent,
  updateContent,
} from '@/lib/data/repositories/content-repository';
import {
  createQuiz,
  deleteQuiz,
  updateQuiz,
  uploadQuizExcel,
} from '@/lib/data/repositories/content-quiz-repository';
import { CONTENT_TYPE_CODE, type ContentKind } from '@/lib/domain/content';
import {
  validateComicForm,
  validateQuizForm,
  validateShortsForm,
  type ContentFormState,
} from '@/lib/domain/content-form';
import { contentListPath } from '@/lib/domain/content-query';
import { FILE_MODULE_ID, MAX_ATTACHMENT_BYTES } from '@/lib/domain/file-module';

/**
 * 콘텐츠관리 Server Action — 세 종류가 같은 파일을 쓴다(폼 구조가 거의 같다).
 *
 * 이슈: 등록·수정·삭제 API가 백엔드에 아직 없다. Repository가 예상 규약대로 호출하고 여기서
 *   실패 사유를 그대로 화면에 돌려준다.
 */

const SAVE_FAILED_MESSAGE = '저장하지 못했습니다. 잠시 후 다시 시도해 주세요.';
const DELETE_FAILED_MESSAGE = '삭제하지 못했습니다. 잠시 후 다시 시도해 주세요.';
const UPLOAD_FAILED_MESSAGE = '파일을 업로드하지 못했습니다.';
const OVERSIZE_MESSAGE = `첨부파일은 ${Math.floor(MAX_ATTACHMENT_BYTES / (1024 * 1024))}MB까지 올릴 수 있습니다.`;

function readString(formData: FormData, key: string): string {
  const value = formData.get(key);
  return typeof value === 'string' ? value : '';
}

function readFiles(formData: FormData, key: string): Array<File | null> {
  return formData
    .getAll(key)
    .map((entry) =>
      entry instanceof File && entry.size > 0 ? entry : null
    );
}

function readGrades(formData: FormData): string[] {
  return readString(formData, 'grades')
    .split(',')
    .map((grade) => grade.trim())
    .filter(Boolean);
}

function readKeywords(formData: FormData) {
  const names = formData.getAll('keyword');
  const descriptions = formData.getAll('keywordDescription');
  return names.map((name, index) => ({
    keyword: typeof name === 'string' ? name : '',
    description:
      typeof descriptions[index] === 'string' ? (descriptions[index] as string) : '',
  }));
}

/** 새로 고른 파일을 올려 파일 ID를 얻는다. 고르지 않았으면 폼이 들고 있던 기존 ID를 그대로 쓴다. */
async function resolveFileId(
  file: File | null,
  retainedId: string
): Promise<string> {
  if (!file) {
    return retainedId;
  }
  if (file.size > MAX_ATTACHMENT_BYTES) {
    throw new Error(OVERSIZE_MESSAGE);
  }
  return uploadAttachment(file, FILE_MODULE_ID.content);
}

function failure(error: unknown, fallback: string): ContentFormState {
  return {
    status: 'error',
    message: error instanceof Error && error.message ? error.message : fallback,
  };
}

export async function createShortsAction(
  _prevState: ContentFormState,
  formData: FormData
): Promise<ContentFormState> {
  await verifySession();

  const validation = validateShortsForm({
    schoolLevel: readString(formData, 'schoolLevel'),
    grades: readGrades(formData),
    title: readString(formData, 'title'),
    subject: readString(formData, 'subject'),
    keywords: readKeywords(formData),
    message: readString(formData, 'message'),
    videoFileId: readString(formData, 'videoFileId'),
    thumbnailFileId: readString(formData, 'thumbnailFileId'),
    isVisible: readString(formData, 'isVisible') === 'true',
  });
  if (!validation.ok) {
    return { status: 'error', errors: validation.errors };
  }

  try {
    const values = {
      ...validation.values,
      videoFileId: await resolveFileId(
        readFiles(formData, 'videoFile')[0] ?? null,
        validation.values.videoFileId
      ),
      thumbnailFileId: await resolveFileId(
        readFiles(formData, 'thumbnailFile')[0] ?? null,
        validation.values.thumbnailFileId
      ),
    };
    await createContent(
      'shorts',
      buildShortsPayload(values),
      CONTENT_TYPE_CODE.shorts
    );
  } catch (error) {
    return failure(error, SAVE_FAILED_MESSAGE);
  }

  revalidatePath(contentListPath('shorts'));
  redirect(contentListPath('shorts'));
}

export async function updateShortsAction(
  _prevState: ContentFormState,
  formData: FormData
): Promise<ContentFormState> {
  await verifySession();

  const cntntsSn = readString(formData, 'cntntsSn');
  const validation = validateShortsForm({
    schoolLevel: readString(formData, 'schoolLevel'),
    grades: readGrades(formData),
    title: readString(formData, 'title'),
    subject: readString(formData, 'subject'),
    keywords: readKeywords(formData),
    message: readString(formData, 'message'),
    videoFileId: readString(formData, 'videoFileId'),
    thumbnailFileId: readString(formData, 'thumbnailFileId'),
    isVisible: readString(formData, 'isVisible') === 'true',
  });
  if (!cntntsSn) {
    return { status: 'error', message: '요청이 올바르지 않습니다.' };
  }
  if (!validation.ok) {
    return { status: 'error', errors: validation.errors };
  }

  try {
    const values = {
      ...validation.values,
      videoFileId: await resolveFileId(
        readFiles(formData, 'videoFile')[0] ?? null,
        validation.values.videoFileId
      ),
      thumbnailFileId: await resolveFileId(
        readFiles(formData, 'thumbnailFile')[0] ?? null,
        validation.values.thumbnailFileId
      ),
    };
    await updateContent('shorts', cntntsSn, buildShortsPayload(values));
  } catch (error) {
    return failure(error, SAVE_FAILED_MESSAGE);
  }

  revalidatePath(contentListPath('shorts'));
  redirect(contentListPath('shorts'));
}

async function resolveCutFileIds(formData: FormData): Promise<string[]> {
  const files = readFiles(formData, 'cutFile');
  const retained = formData
    .getAll('cutFileId')
    .map((entry) => (typeof entry === 'string' ? entry : ''));

  const ids: string[] = [];
  for (const [index, file] of files.entries()) {
    const id = await resolveFileId(file, retained[index] ?? '');
    if (id) {
      ids.push(id);
    }
  }
  return ids;
}

export async function createComicAction(
  _prevState: ContentFormState,
  formData: FormData
): Promise<ContentFormState> {
  await verifySession();

  let cutFileIds: string[];
  let thumbnailFileId: string;
  try {
    cutFileIds = await resolveCutFileIds(formData);
    thumbnailFileId = await resolveFileId(
      readFiles(formData, 'thumbnailFile')[0] ?? null,
      readString(formData, 'thumbnailFileId')
    );
  } catch (error) {
    return failure(error, UPLOAD_FAILED_MESSAGE);
  }

  const validation = validateComicForm({
    schoolLevel: readString(formData, 'schoolLevel'),
    grades: readGrades(formData),
    name: readString(formData, 'name'),
    subject: readString(formData, 'subject'),
    keywords: readKeywords(formData),
    message: readString(formData, 'message'),
    thumbnailFileId,
    cutFileIds,
    isVisible: readString(formData, 'isVisible') === 'true',
  });
  if (!validation.ok) {
    return { status: 'error', errors: validation.errors };
  }

  try {
    await createContent(
      'comic',
      buildComicPayload(validation.values),
      CONTENT_TYPE_CODE.comic
    );
  } catch (error) {
    return failure(error, SAVE_FAILED_MESSAGE);
  }

  revalidatePath(contentListPath('comic'));
  redirect(contentListPath('comic'));
}

export async function updateComicAction(
  _prevState: ContentFormState,
  formData: FormData
): Promise<ContentFormState> {
  await verifySession();

  const cntntsSn = readString(formData, 'cntntsSn');
  if (!cntntsSn) {
    return { status: 'error', message: '요청이 올바르지 않습니다.' };
  }

  let cutFileIds: string[];
  let thumbnailFileId: string;
  try {
    cutFileIds = await resolveCutFileIds(formData);
    thumbnailFileId = await resolveFileId(
      readFiles(formData, 'thumbnailFile')[0] ?? null,
      readString(formData, 'thumbnailFileId')
    );
  } catch (error) {
    return failure(error, UPLOAD_FAILED_MESSAGE);
  }

  const validation = validateComicForm({
    schoolLevel: readString(formData, 'schoolLevel'),
    grades: readGrades(formData),
    name: readString(formData, 'name'),
    subject: readString(formData, 'subject'),
    keywords: readKeywords(formData),
    message: readString(formData, 'message'),
    thumbnailFileId,
    cutFileIds,
    isVisible: readString(formData, 'isVisible') === 'true',
  });
  if (!validation.ok) {
    return { status: 'error', errors: validation.errors };
  }

  try {
    await updateContent('comic', cntntsSn, buildComicPayload(validation.values));
  } catch (error) {
    return failure(error, SAVE_FAILED_MESSAGE);
  }

  revalidatePath(contentListPath('comic'));
  redirect(contentListPath('comic'));
}

function readQuizValues(formData: FormData) {
  return {
    schoolLevel: readString(formData, 'schoolLevel'),
    grades: readGrades(formData),
    level: readString(formData, 'level'),
    keywords: readKeywords(formData),
    question: readString(formData, 'question'),
    answer: readString(formData, 'answer'),
    answerMessageCode: readString(formData, 'answerMessageCode'),
    answerMessageText: readString(formData, 'answerMessageText'),
    explanation: readString(formData, 'explanation'),
    isVisible: readString(formData, 'isVisible') === 'true',
  };
}

export async function createQuizAction(
  _prevState: ContentFormState,
  formData: FormData
): Promise<ContentFormState> {
  await verifySession();

  const validation = validateQuizForm(readQuizValues(formData));
  if (!validation.ok) {
    return { status: 'error', errors: validation.errors };
  }

  try {
    await createQuiz(validation.values);
  } catch (error) {
    return failure(error, SAVE_FAILED_MESSAGE);
  }

  revalidatePath(contentListPath('quiz'));
  redirect(contentListPath('quiz'));
}

export async function updateQuizAction(
  _prevState: ContentFormState,
  formData: FormData
): Promise<ContentFormState> {
  await verifySession();

  const quizSn = readString(formData, 'quizSn');
  if (!quizSn) {
    return { status: 'error', message: '요청이 올바르지 않습니다.' };
  }

  const validation = validateQuizForm(readQuizValues(formData));
  if (!validation.ok) {
    return { status: 'error', errors: validation.errors };
  }

  try {
    await updateQuiz(quizSn, validation.values);
  } catch (error) {
    return failure(error, SAVE_FAILED_MESSAGE);
  }

  revalidatePath(contentListPath('quiz'));
  redirect(contentListPath('quiz'));
}

export async function deleteContentAction(
  kind: ContentKind,
  id: string
): Promise<ContentFormState> {
  await verifySession();

  if (!id) {
    return { status: 'error', message: '요청이 올바르지 않습니다.' };
  }

  try {
    if (kind === 'quiz') {
      await deleteQuiz(id);
    } else {
      await deleteContent(kind, id);
    }
  } catch (error) {
    return failure(error, DELETE_FAILED_MESSAGE);
  }

  revalidatePath(contentListPath(kind));
  return { status: 'success' };
}

/** 금융OX퀴즈 엑셀 일괄등록. 한 행이라도 검증에 실패하면 백엔드가 전체를 되돌린다. */
export async function uploadQuizExcelAction(
  _prevState: ContentFormState,
  formData: FormData
): Promise<ContentFormState> {
  await verifySession();

  const file = readFiles(formData, 'excelFile')[0] ?? null;
  if (!file) {
    return { status: 'error', message: '엑셀 파일을 선택해 주세요.' };
  }

  try {
    await uploadQuizExcel(file);
  } catch (error) {
    return failure(error, '엑셀을 등록하지 못했습니다.');
  }

  revalidatePath(contentListPath('quiz'));
  return { status: 'success' };
}