import type {
  AdminImportAgcTemplateItemPayload,
  AdminImportAgcTemplatesManifest,
} from '../api/adminApiTypes';

/** 与服务端 module-assets 的导入上限保持一致；超出请分批或改走 CLI。 */
export const TEMPLATE_IMPORT_MAX_BATCH = 20;
export const TEMPLATE_UPLOAD_RUNTIMES = [
  'html',
  'unity',
  'godot',
  'cocos',
] as const;
const TEMPLATE_ID_PATTERN = /^[a-z0-9][a-z0-9._-]{0,63}$/u;
const TEMPLATE_VERSION_PATTERN = /^[a-z0-9][a-z0-9._-]{0,31}$/u;
const ENTRY_PATTERN = /^(?![\\/:])(?!.*\.\.)[^\s\\:]+$/u;
const COVER_EXTENSION_PATTERN = /\.(png|jpe?g|webp)$/iu;

export interface TemplateUploadRow {
  /** 稳定行标识：用 ZIP 文件名，重选文件后不会串行。 */
  key: string;
  zipFile: File;
  coverFile: File | null;
  id: string;
  title: string;
  summary: string;
  tags: string;
  runtime: string;
  engine: string;
  engineVersion: string;
  templateVersion: string;
  entry: string;
}

/** 文件名 → 模板 ID：小写、只留白名单字符，并去掉 `..` 与开头的非字母数字。 */
export function sanitizeTemplateId(value: string) {
  return value
    .replace(/\.zip$/iu, '')
    .trim()
    .toLowerCase()
    .replace(/\.{2,}/gu, '.')
    .replace(/[^a-z0-9._-]+/gu, '-')
    .replace(/^[^a-z0-9]+/u, '')
    .slice(0, 64);
}

export function deriveTemplateUploadRow(zipFile: File): TemplateUploadRow {
  const id = sanitizeTemplateId(zipFile.name);
  return {
    key: zipFile.name,
    zipFile,
    coverFile: null,
    id,
    title: id,
    summary: '',
    tags: '',
    runtime: 'html',
    engine: '',
    engineVersion: '',
    templateVersion: '0.1.0',
    entry: 'index.html',
  };
}

/** 封面按「与模板 ID 同名的图片」匹配，一次多选即可覆盖整批。 */
export function attachCoverFiles(
  rows: TemplateUploadRow[],
  coverFiles: File[],
): TemplateUploadRow[] {
  const covers = new Map<string, File>();
  for (const file of coverFiles) {
    if (!COVER_EXTENSION_PATTERN.test(file.name)) continue;
    const stem = sanitizeTemplateId(
      file.name.replace(COVER_EXTENSION_PATTERN, ''),
    );
    if (!covers.has(stem)) covers.set(stem, file);
  }
  return rows.map((row) => {
    const matched = covers.get(row.id.trim().toLowerCase()) ?? null;
    return matched ? { ...row, coverFile: matched } : row;
  });
}

export function parseTemplateTags(value: string) {
  const seen = new Set<string>();
  const tags: string[] = [];
  for (const raw of value.split(/[,，\s]+/u)) {
    const tag = raw.trim();
    if (!tag || seen.has(tag)) continue;
    seen.add(tag);
    tags.push(tag);
  }
  return tags.slice(0, 16);
}

/** 逐行校验：返回 row.key → 错误文案；空对象表示整批可以提交。 */
export function validateTemplateUploadRows(
  rows: TemplateUploadRow[],
): Record<string, string> {
  const errors: Record<string, string> = {};
  const seen = new Set<string>();
  const fail = (row: TemplateUploadRow, message: string) => {
    if (!errors[row.key]) errors[row.key] = message;
  };
  if (rows.length === 0) return errors;
  if (rows.length > TEMPLATE_IMPORT_MAX_BATCH) {
    for (const row of rows) {
      fail(row, `单批最多上传 ${TEMPLATE_IMPORT_MAX_BATCH} 个模板`);
    }
    return errors;
  }
  for (const row of rows) {
    const id = row.id.trim();
    if (!TEMPLATE_ID_PATTERN.test(id)) {
      fail(
        row,
        'ID 必须是 1-64 位小写字母、数字、点、下划线或连字符，且以字母数字开头',
      );
    } else if (seen.has(id)) {
      fail(row, 'ID 在本批次内重复');
    } else {
      seen.add(id);
    }
    if (!row.title.trim() || row.title.trim().length > 80) {
      fail(row, '名称必须是 1-80 个字符');
    }
    if (row.summary.trim().length > 1000) {
      fail(row, '简介最多 1000 个字符');
    }
    if (!TEMPLATE_VERSION_PATTERN.test(row.templateVersion.trim())) {
      fail(row, '版本号必须是 1-32 位小写字母、数字、点、下划线或连字符');
    }
    if (
      !TEMPLATE_UPLOAD_RUNTIMES.includes(
        row.runtime as (typeof TEMPLATE_UPLOAD_RUNTIMES)[number],
      )
    ) {
      fail(row, `运行时只能是 ${TEMPLATE_UPLOAD_RUNTIMES.join(' / ')}`);
    }
    if (!ENTRY_PATTERN.test(row.entry.trim())) {
      fail(row, 'entry 必须是模板包内的相对路径');
    }
    if (!row.coverFile) {
      fail(row, '缺少封面：请上传与模板 ID 同名的 PNG / JPEG / WebP');
    }
  }
  return errors;
}

export function buildTemplateImportManifest(
  expectedRevision: string,
  rows: TemplateUploadRow[],
): AdminImportAgcTemplatesManifest {
  return {
    expectedRevision,
    templates: rows.map((row, index) => {
      const item: AdminImportAgcTemplateItemPayload = {
        id: row.id.trim(),
        title: row.title.trim(),
        summary: row.summary.trim(),
        tags: parseTemplateTags(row.tags),
        runtime: row.runtime,
        engine: row.engine.trim(),
        engineVersion: row.engineVersion.trim(),
        templateVersion: row.templateVersion.trim(),
        entry: row.entry.trim(),
        zipField: `zip_${index}`,
        coverField: `cover_${index}`,
      };
      return item;
    }),
  };
}

export function buildTemplateImportFormData(
  expectedRevision: string,
  rows: TemplateUploadRow[],
): FormData {
  const form = new FormData();
  form.append(
    'manifest',
    JSON.stringify(buildTemplateImportManifest(expectedRevision, rows)),
  );
  rows.forEach((row, index) => {
    form.append(`zip_${index}`, row.zipFile, row.zipFile.name);
    if (row.coverFile) {
      form.append(`cover_${index}`, row.coverFile, row.coverFile.name);
    }
  });
  return form;
}