/*
 This file is part of TALER
 (C) 2016 GNUnet e.V.

 TALER is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3, or (at your option) any later version.

 TALER is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */


/**
 * Generate .po file from list of source files.
 *
 * Note that duplicate message IDs are NOT merged, to get the same output as
 * you would from xgettext, just run msguniq.
 *
 * @author Florian Dold
 */

"use strict";

import {readFileSync} from "fs";
import * as ts from "typescript";


function wordwrap(str: string, width: number = 80): string[] {
    var regex = '.{1,' + width + '}(\\s|$)|\\S+(\\s|$)';
    return str.match(RegExp(regex, 'g'));
}

export function processFile(sourceFile: ts.SourceFile) {
  processNode(sourceFile);
  let lastTokLine = 0;
  let preLastTokLine = 0;

  function getTemplate(node: ts.Node): string {
    switch (node.kind) {
      case ts.SyntaxKind.FirstTemplateToken:
        return (<any>node).text;
      case ts.SyntaxKind.TemplateExpression:
        let te = <ts.TemplateExpression>node;
        let textFragments = [te.head.text];
        for (let tsp of te.templateSpans) {
          textFragments.push(`%${(textFragments.length-1)/2+1}$s`);
          textFragments.push(tsp.literal.text.replace(/%/g, "%%"));
        }
        return textFragments.join('');
      default:
        return "(pogen.ts: unable to parse)";
    }
  }

  function getComment(node: ts.Node): string {
    let lc = ts.getLineAndCharacterOfPosition(sourceFile, node.pos);
    let lastComments;
    for (let l = preLastTokLine; l < lastTokLine; l++) {
      let pos = ts.getPositionOfLineAndCharacter(sourceFile, l, 0);
      let comments = ts.getTrailingCommentRanges(sourceFile.text, pos);
      if (comments) {
        lastComments = comments;
      }
    }
    if (!lastComments) {
      return;
    }
    let candidate = lastComments[lastComments.length-1];
    let candidateEndLine = ts.getLineAndCharacterOfPosition(sourceFile, candidate.end).line;
    if (candidateEndLine != lc.line - 1) {
      return;
    }
    let text = sourceFile.text.slice(candidate.pos, candidate.end);
    switch (candidate.kind) {
      case ts.SyntaxKind.SingleLineCommentTrivia:
        // Remove comment leader
        text = text.replace(/^[/][/]\s*/, "");
        break;
      case ts.SyntaxKind.MultiLineCommentTrivia:
        // Remove comment leader and trailer,
        // handling white space just like xgettext.
        text = text
            .replace(/^[/][*](\s*?\n|\s*)?/, "")
            .replace(/(\n[ \t]*?)?[*][/]$/, "");
        break;
    }
    return text;
  }

  function getPath(node: ts.Node): string[] {
    switch (node.kind) {
      case ts.SyntaxKind.PropertyAccessExpression:
        let pae = <ts.PropertyAccessExpression>node;
        return Array.prototype.concat(getPath(pae.expression), [pae.name.text]);
      case ts.SyntaxKind.Identifier:
        let id = <ts.Identifier>node;
        return [id.text];
    }
    return ["(other)"];
  }

  function arrayEq<T>(a1: T[], a2: T[]) {
    if (a1.length != a2.length) {
      return false;
    }
    for (let i = 0; i < a1.length; i++) {
      if (a1[i] != a2[i]) {
        return false;
      }
    }
    return true;
  }

  interface TemplateResult {
    comment: string;
    path: string[];
    template: string;
    line: number;
  }

  function processTaggedTemplateExpression(tte: ts.TaggedTemplateExpression): TemplateResult {
    let lc = ts.getLineAndCharacterOfPosition(sourceFile, tte.pos);
    if (lc.line != lastTokLine) {
      preLastTokLine = lastTokLine;
      lastTokLine = lc.line;
    }
    let path = getPath(tte.tag)
    let res: TemplateResult = {
      path,
      line: lc.line,
      comment: getComment(tte),
      template: getTemplate(tte.template).replace(/"/g, '\\"'),
    };
    return res;
  }

  function formatMsgComment(line: number, comment?: string) {
    if (comment) {
      for (let cl of comment.split('\n')) {
        console.log(`#. ${cl}`);
      }
    }
    console.log(`#: ${sourceFile.fileName}:${line+1}`);
    console.log(`#, c-format`);
  }

  function formatMsgLine(head: string, msg: string) {
    // Do escaping, wrap break at newlines
    let parts = msg
        .match(/(.*\n|.+$)/g)
        .map((x) => x.replace(/\n/g, '\\n'))
        .map((p) => wordwrap(p))
        .reduce((a,b) => a.concat(b));
    if (parts.length == 1) {
      console.log(`${head} "${parts[0]}"`);
    } else {
      console.log(`${head} ""`);
      for (let p of parts) {
        console.log(`"${p}"`);
      }
    }
  }

  interface JsxProcessingContext {

  }

  function getJsxElementPath(node: ts.Node) {
    let path;
    let process = (childNode) => {
      switch (childNode.kind) {
        case ts.SyntaxKind.JsxOpeningElement:
        {
          let e = childNode as ts.JsxOpeningElement;
          return path = getPath(e.tagName);
        }
        default:
          break;
      }
    };
    ts.forEachChild(node, process);
    return path;
  }

  function translateJsxExpression(node: ts.Node, h) {
      switch (node.kind) {
        case ts.SyntaxKind.StringLiteral:
        {
          let e = node as ts.StringLiteral;  
          return e.text;
        }
        default:
          return `%${h[0]++}$s`;
      }
  }

  function trim(s) {
    return s.replace(/^[ \n\t]*/, "").replace(/[ \n\t]*$/, "");
  }

  function getJsxContent(node: ts.Node) {
    let fragments = [];
    let holeNum = [1];
    let process = (childNode) => {
      switch (childNode.kind) {
        case ts.SyntaxKind.JsxText:
        {
          let e = childNode as ts.JsxText;
          let s = e.getFullText();
          let t = s.split("\n").map(trim).join(" ");
          fragments.push(t);
        }
        case ts.SyntaxKind.JsxOpeningElement:
          break;
        case ts.SyntaxKind.JsxElement:
          fragments.push(`%${holeNum[0]++}$s`);
          break;
        case ts.SyntaxKind.JsxExpression:
        {
          let e = childNode as ts.JsxExpression;
          fragments.push(translateJsxExpression(e.expression, holeNum));
          break;
        }
        case ts.SyntaxKind.JsxClosingElement:
          break;
        default:
          let lc = ts.getLineAndCharacterOfPosition(childNode.getSourceFile(), childNode.getStart());
          console.error(`unrecognized syntax in JSX Element ${ts.SyntaxKind[childNode.kind]} (${childNode.getSourceFile().fileName}:${lc.line+1}:${lc.character+1}`);
          break;
      }
    };
    ts.forEachChild(node, process);
    return fragments.join("").trim().replace(/ +/g, " ");
  }

  function getJsxSingular(node: ts.Node) {
    let res;
    let process = (childNode) => {
      switch (childNode.kind) {
        case ts.SyntaxKind.JsxElement:
        {
          let path = getJsxElementPath(childNode);
          if (arrayEq(path, ["i18n", "TranslateSingular"])) {
            res = getJsxContent(childNode);
          }
        }
        default:
          break;
      }
    };
    ts.forEachChild(node, process);
    return res;
  }

  function getJsxPlural(node: ts.Node) {
    let res;
    let process = (childNode) => {
      switch (childNode.kind) {
        case ts.SyntaxKind.JsxElement:
        {
          let path = getJsxElementPath(childNode);
          if (arrayEq(path, ["i18n", "TranslatePlural"])) {
            res = getJsxContent(childNode);
          }
        }
        default:
          break;
      }
    };
    ts.forEachChild(node, process);
    return res;
  }
  

  function processNode(node: ts.Node) {
    switch (node.kind) {
      case ts.SyntaxKind.JsxElement:
        let path = getJsxElementPath(node);
        if (arrayEq(path, ["i18n", "Translate"])) {
          let content = getJsxContent(node);
          let {line} = ts.getLineAndCharacterOfPosition(sourceFile, node.pos);
          let comment = getComment(node);
          formatMsgComment(line, comment);
          formatMsgLine("msgid", content);
          console.log(`msgstr ""`);
          console.log();
          return;
        }
        if (arrayEq(path, ["i18n", "TranslateSwitch"])) {
          let {line} = ts.getLineAndCharacterOfPosition(sourceFile, node.pos);
          let comment = getComment(node);
          formatMsgComment(line, comment);
          let singularForm = getJsxSingular(node);
          if (!singularForm) {
            console.error("singular form missing");
            process.exit(1);
          }
          let pluralForm = getJsxPlural(node);
          if (!pluralForm) {
            console.error("plural form missing");
            process.exit(1);
          }
          formatMsgLine("msgid", singularForm);
          formatMsgLine("msgid_plural", pluralForm);
          console.log(`msgstr[0] ""`);
          console.log(`msgstr[1] ""`);
          console.log();
          return;
        }
        break;
      case ts.SyntaxKind.CallExpression:
      {
        // might be i18n.plural(i18n[.X]`...`, i18n[.X]`...`)
        let ce = <ts.CallExpression>node;
        let path = getPath(ce.expression);
        if (!arrayEq(path, ["i18n", "plural"])) {
          break;
        }
        if (ce.arguments[0].kind != ts.SyntaxKind.TaggedTemplateExpression) {
          break;
        }
        if (ce.arguments[1].kind != ts.SyntaxKind.TaggedTemplateExpression) {
          break;
        }
        let {line} = ts.getLineAndCharacterOfPosition(sourceFile, ce.pos);
        let t1 = processTaggedTemplateExpression(<ts.TaggedTemplateExpression>ce.arguments[0]);
        let t2 = processTaggedTemplateExpression(<ts.TaggedTemplateExpression>ce.arguments[1]);
        let comment = getComment(ce);

        formatMsgComment(line, comment);
        formatMsgLine("msgid", t1.template);
        formatMsgLine("msgid_plural", t2.template);
        console.log(`msgstr[0] ""`);
        console.log(`msgstr[1] ""`);
        console.log();

        // Important: no processing for child i18n expressions here
        return;
      }
      case ts.SyntaxKind.TaggedTemplateExpression:
      {
        let tte = <ts.TaggedTemplateExpression>node;
        let {comment, template, line, path} = processTaggedTemplateExpression(tte);
        if (path[0] != "i18n") {
          break;
        }
        formatMsgComment(line, comment);
        formatMsgLine("msgid", template);
        console.log(`msgstr ""`);
        console.log();
        break;
      }
    }

    ts.forEachChild(node, processNode);
  }
}

const fileNames = process.argv.slice(2);

console.log(
`# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
# This file is distributed under the same license as the PACKAGE package.
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\\n"
"Report-Msgid-Bugs-To: \\n"
"POT-Creation-Date: 2016-11-23 00:00+0100\\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\\n"
"Language-Team: LANGUAGE <LL@li.org>\\n"
"Language: \\n"
"MIME-Version: 1.0\\n"
"Content-Type: text/plain; charset=UTF-8\\n"
"Content-Transfer-Encoding: 8bit\\n"`);
console.log()

fileNames.sort();

fileNames.forEach(fileName => {
  let sourceFile = ts.createSourceFile(fileName, readFileSync(fileName).toString(), ts.ScriptTarget.ES2016, /*setParentNodes */ true);
  processFile(sourceFile);
});