import MathMl2LaTeX from 'mathml2latex';

import { Token } from '../types.js';

import type {
  ContextStash,
  TokenHandler,
} from '../MarkdownSerializer.js';
import { getInlineTokensHandlers } from './inline_token_handlers.js';

export function getHtmlBasicTokensHandlers(): Record<
  string,
  Array<TokenHandler>
> {
  return {
    'frontmatter': [],
    'heading_open': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log(`<${token.tag}>`, token);
      },
    ],
    'heading_close': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log(`</${token.tag}>\n`, token);
      },
    ],
    'paragraph_open': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log('<p>', token);
      },
    ],
    'paragraph_close': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log('</p>\n', token);
      },
    ],

    'fence': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log('<pre>' + token.content + '</pre>\n', token);
        // ctx.current.log('```' + token.info + '\n' + token.content + '```\n\n', token);
      },
    ],

    'code_block': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log('<pre>' + token.content + '</pre>\n', token);
        // ctx.current.log(
        //   token.content
        //     .split('\n')
        //     .map((t) => t ? ('    ' + t) : '')
        //     .join('\n') + '\n', token
        // );
      },
    ],

    'hr': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log('<hr />\n', token);
      },
    ],

    'html_block': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log(token.content, token);
      },
    ],
  };
}

function getHeaderTokensHandlers(): Record<string, Array<TokenHandler>> {
  const entriesBasic = Object.entries(getBasicTokensHandlers())
    .filter((entry) => ['heading_close'].includes(entry[0]));

  const entriesInline = Object.entries(getInlineTokensHandlers())
    .filter((entry) => ['text', 'link_open', 'link_close'].includes(entry[0]));

  return {
    ...Object.fromEntries(entriesInline),
    ...Object.fromEntries(entriesBasic),
    'default': [],
  };
}

export function getBasicTokensHandlers(): Record<string, Array<TokenHandler>> {
  return {
    'frontmatter': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log(
          token.content,
          token,
        );
      },
    ],
    'heading_open': [
      (token: Token, ctx: ContextStash) => {
        ctx.stash('getBasicTokensHandlers.heading_open');
        ctx.current.handlers = getHeaderTokensHandlers();
        if (token.markup === '---') {
          return;
        }
        ctx.current.log('#'.repeat(+token.tag.substring(1)) + ' ', token);
      },
    ],
    'heading_close': [
      (token: Token, ctx: ContextStash) => {
        if (token.markup === '---') {
          ctx.current.log('\n' + token.markup + '\n', token);
        }
        ctx.current.log('\n', token);
        ctx.unstash('getBasicTokensHandlers.heading_close');
      },
    ],
    'paragraph_open': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log('', token);
        // Skip, as paragraphs are implied by newlines
      },
    ],
    'paragraph_close': [
      (token: Token, ctx: ContextStash) => {
        if (ctx.output.colPos !== 0) {
          ctx.current.log('\n', token);
        }
      },
    ],

    'fence': [
      (token: Token, ctx: ContextStash) => {
        let content = token.content;
        let lang = token.attrGet('lang') || '';

        if (lang === 'mathml') {
          lang = 'math';
          const cleaned = content.replace(
            /<annotation[\s\S]*?<\/annotation>/g,
            '',
          );
          content = MathMl2LaTeX.convert(cleaned);
        }

        if (!content.endsWith('\n')) {
          content += '\n';
        }

        if (lang === 'latex') {
          ctx.current.log(
            '$$' + '\n' + content + '$$\n\n',
            token,
          );
        } else {
          ctx.current.log(
            '```' + lang + '\n' + content + '```\n\n',
            token,
          );
        }
      },
    ],

    'code_block': [
      (token: Token, ctx: ContextStash) => {
        const indent = +(token.attrGet('indent') || 0);
        let content = token.content;
        let lang = token.attrGet('lang') || '';

        if (indent === 0) {
          if (lang === 'mathml') {
            lang = 'math';
            const cleaned = content.replace(
              /<annotation[\s\S]*?<\/annotation>/g,
              '',
            );
            content = MathMl2LaTeX.convert(cleaned);
          }

          if (!content.endsWith('\n')) {
            content += '\n';
          }

          if (lang === 'rawmd') {
            ctx.current.log(content, token);
          } else if (lang === 'latex') {
            ctx.current.log(
              '$$' + '\n' + content + '$$\n\n',
              token,
            );
          } else {
            ctx.current.log(
              '```' + lang + '\n' + content + '```\n',
              token,
            );
          }
          return;
        }

        ctx.current.log(
          token.content
            .split('\n')
            .map((t) => t ? (' '.repeat(indent) + t) : '')
            .join('\n'),
          token,
        );
      },
    ],

    'hr': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log((token.markup || '___') + '\n', token);
      },
    ],

    'html_block': [
      (token: Token, ctx: ContextStash) => {
        ctx.current.log(token.content, token);
      },
    ],
  };
}