import { existsSync, mkdirSync, readFileSync, statSync } from 'node:fs';
import fs from 'node:fs/promises';
import path, { join } from 'node:path';
import { fileURLToPath } from 'node:url';

import JSZip from 'jszip';

const __dirname = join(fileURLToPath(import.meta.url), '..');
const ZIP_PATH = join(__dirname, './edgeless-snapshot');
const ASSETS_PREFIX = `/static/templates`;
const ASSETS_PATH = join(__dirname, '../core/public/', ASSETS_PREFIX);
const TEMPLATE_PATH = join(__dirname, './edgeless');

const getZipFilesInCategroies = () => {
  return fs.readdir(ZIP_PATH).then(folders => {
    return Promise.all(
      folders
        .filter(folder => {
          return statSync(join(ZIP_PATH, folder)).isDirectory();
        })
        .map(async folder => {
          const files = await fs.readdir(join(ZIP_PATH, folder));
          return {
            category: folder,
            files: files.filter(file => path.extname(file) === '.zip'),
          };
        })
    );
  });
};

const setupFolder = async () => {
  if (!existsSync(ASSETS_PATH)) {
    mkdirSync(ASSETS_PATH);
  }

  if (!existsSync(TEMPLATE_PATH)) {
    mkdirSync(TEMPLATE_PATH);
  }
};

/**
 * @typedef Block
 * @type {object}
 * @property {string} flavour
 * @property {Array<Block> | undefined} children
 * @property {object} props
 * @property {string} props.sourceId
 */

/**
 * @param {Block} block
 */
const convertSourceId = (block, assetsExtMap) => {
  if (block.props?.sourceId) {
    const extname = assetsExtMap[block.props.sourceId];
    if (!extname) {
      console.warn(`No extname found for ${block.props.sourceId}`);
    }
    block.props.sourceId = `${ASSETS_PREFIX}/${block.props.sourceId}${
      extname ?? ''
    }`;
  }

  if (block.children && Array.isArray(block.children)) {
    block.children.forEach(block => convertSourceId(block, assetsExtMap));
  }
};

const parseSnapshot = async () => {
  const filesInCategroies = await getZipFilesInCategroies();
  await setupFolder();
  /**
   * @type {Array<{ category: string, templates: string[] }}>}
   */
  const templatesInCategory = [];

  for (let cate of filesInCategroies) {
    const templates = [];
    const assetsExtentionMap = {};

    for (let file of cate.files) {
      const templateName = path.basename(file, '.zip');
      const zip = new JSZip();
      const { files: unarchivedFiles } = await zip.loadAsync(
        readFileSync(join(ZIP_PATH, cate.category, file))
      );
      /**
       * @type {Array<JSZip.JSZipObject>}
       */
      const assetsFiles = [];
      /**
       * @type {Array<JSZip.JSZipObject>}
       */
      const snapshotFiles = [];

      Object.entries(unarchivedFiles).forEach(([name, fileObj]) => {
        if (name.includes('MACOSX') || name.includes('__MACOSX')) return;

        if (name.includes('assets/') && !fileObj.dir) {
          assetsFiles.push(fileObj);
          return;
        }

        if (name.endsWith('.snapshot.json')) {
          snapshotFiles.push(fileObj);
          return;
        }
      });

      await Promise.all(
        assetsFiles.map(async file => {
          const blob = await file.async('blob');
          const arrayBuffer = await blob.arrayBuffer();
          const buffer = Buffer.from(arrayBuffer, 'binary');
          const extname = path.extname(file.name);

          assetsExtentionMap[
            file.name.replace(/.*assets\//, '').replace(extname, '')
          ] = extname;

          await fs.writeFile(
            join(ASSETS_PATH, file.name.replace(/.*assets\//, '')),
            buffer
          );
        })
      );

      await Promise.all(
        snapshotFiles.map(async snapshot => {
          const json = await snapshot.async('text');
          const snapshotContent = JSON.parse(json);
          const previewPath = join(
            ZIP_PATH,
            cate.category,
            `${templateName}.svg`
          );
          let previewContent = '';

          if (existsSync(previewPath)) {
            const previewFile = readFileSync(previewPath, 'utf-8');
            previewContent = previewFile
              .replace(/\n/g, '')
              .replace(/\s+/g, ' ')
              .replace('fill="white"', 'fill="currentColor"');
          } else {
            console.warn(`No preview found for ${templateName}`);
          }

          convertSourceId(snapshotContent.blocks, assetsExtentionMap);

          const template = {
            name: templateName,
            type: 'template',
            preview: previewContent,
            content: snapshotContent,
          };

          await fs.writeFile(
            join(join(TEMPLATE_PATH, `${templateName}.json`)),
            JSON.stringify(template, undefined, 2)
          );

          templates.push(templateName);
        })
      );
    }

    templatesInCategory.push({
      category: cate.category,
      templates,
    });
  }

  return templatesInCategory;
};

function numberToWords(n) {
  const ones = [
    'Zero',
    'One',
    'Two',
    'Three',
    'Four',
    'Five',
    'Six',
    'Seven',
    'Eight',
    'Nine',
  ];

  if (n < 10) {
    return ones[n];
  } else {
    throw new Error(`Not implemented: ${n}`);
  }
}

const camelCaseNumber = variable => {
  const words = variable.split(' ');
  return words
    .map(word => word.charAt(0).toUpperCase() + word.slice(1))
    .join('');
};

const toVariableName = name => {
  const converted = Array.from(name).reduce((pre, char) => {
    if (char >= '0' && char <= '9') {
      return pre + numberToWords(char - '0');
    }

    return pre + char;
  }, '');

  return camelCaseNumber(converted);
};

/**
 *
 * @param {Array<{category: string, templates: string[]}} templatesInGroup
 */
const buildScript = async templatesInGroup => {
  const templates = [];
  const templateVariableMap = {};

  templatesInGroup.forEach(group => {
    group.templates.forEach(template => {
      templates.push(template);
      templateVariableMap[template] = toVariableName(template);
    });
  });

  const importStatements = templates
    .map(template => {
      return `import ${toVariableName(
        template
      )} from './edgeless/${template}.json';`;
    })
    .join('\n');
  const templatesDeclaration = templatesInGroup.map(group => {
    return `'${group.category}': [
    ${group.templates
      .map(template => templateVariableMap[template])
      .join(',\n    ')}
  ]`;
  });

  const code = `${importStatements}

const templates = {
  ${templatesDeclaration.join(',\n  ')}
}

function lcs(text1: string, text2: string) {
  const dp: number[][] = Array.from({ length: text1.length + 1 })
    .fill(null)
    .map(() => Array.from<number>({length: text2.length + 1}).fill(0));

  for (let i = 1; i <= text1.length; i++) {
    for (let j = 1; j <= text2.length; j++) {
      if (text1[i - 1] === text2[j - 1]) {
        dp[i][j] = dp[i - 1][j - 1] + 1;
      } else {
        dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);
      }
    }
  }

  return dp[text1.length][text2.length];
}

export const builtInTemplates = {
  list: async (category: string) => {
    // @ts-expect-error type should be asserted when using
    return templates[category] ?? []
  },

  categories: async () => {
    return Object.keys(templates)
  },

  search: async(query: string) => {
    const candidates: unknown[] = [];
    const cates = Object.keys(templates);

    query = query.toLowerCase();

    for(let cate of cates) {
      // @ts-expect-error type should be asserted when using
      const templatesOfCate = templates[cate];

      for(let temp of templatesOfCate) {
        if(lcs(query, temp.name.toLowerCase()) === query.length) {
          candidates.push(temp);
        }
      }
    }

    return candidates;
  },
}
`;

  await fs.writeFile(join(__dirname, './edgeless-templates.gen.ts'), code, {
    encoding: 'utf-8',
  });
};

const templatesInGroup = await parseSnapshot();
await buildScript(templatesInGroup);