// ## kif.js

// KIF is the most popular file format used to represent full shogi games,
// studies of games, tsume problems and other types of puzzles.
// For more information, see https://lishogi.org/page/kif and
// https://deepwiki.com/gunyarakun/python-shogi/3.1-kif-format

const pieceMap = {
  P: "歩",
  L: "香",
  N: "桂",
  S: "銀",
  G: "金",
  B: "角",
  R: "飛",
  K: "玉",
  "+P": "と",
  "+L": "成香",
  "+N": "成桂",
  "+S": "成銀",
  "+B": "馬",
  "+R": "竜"
};

const japaneseNumberMap = {
  1: "一",
  2: "二",
  3: "三",
  4: "四",
  5: "五",
  6: "六",
  7: "七",
  8: "八",
  9: "九"
};

function kifCoord(square) {
  const file = square[0];
  const rank = square[1];
  return `${file}${japaneseNumberMap[rank]}`;
}

// A struct to hold the source or destination square of a move
// file and rank are numbers from 1-9
const Square = (file, rank) => ({ file, rank });

function parseSquare(square) {
  // square is a string like "7g"
  // first character is the file (1-9), second character is the rank (a-i)  
  const file = parseInt(square[0], 10);
  const rank = "abcdefghi".indexOf(square[1]) + 1;
  return Square(file, rank);
}

function toKIF(line, prevDest) {
  // move number
  const move = line.replace(/^\d+:\s*/, "").trim();

  // gote/sente player indicator
  const player = move[0] === "☗" ? "▲" : "△";
  var body = move.slice(1);

  // piece
  if (move[0] === "+") { // promoted piece
    // first two characters are the piece, then the destination
    const piece = body.slice(0, 2);
    body = body.slice(2);
  }
  else {
    // first character is the piece, then the destination
    const piece = body[0];
    body = body.slice(1);
  }

  // source square (optional)
  if (body[0] >= "1" && body[0] <= "9") {
    const sourceSquare = body.slice(0, 2);
    body = body.slice(2);
  }

  // move type
  moveType = body[0]; // either '-' for a normal move, 'x' for a capture, or '*' for a drop
  body = body.slice(1);

  // destination square
  destSquare = body.slice(0, 2);
  body = body.slice(2);

  if (body.length > 0) {
    if (body[0] === "+" || body[0] === "=") {
      const promoFlag = body[0];
      body = body.slice(1);
    } 
  }

  // to KIF format
  var kifMove = `${player}${kifCoord(destSquare)}${pieceMap[piece]}${moveType === "*" ? "打" : ""}`;
  if (promoFlag) {
    kifMove += promoFlag === "+" ? "成" : "不成";
  }
  return kifMove;
}

// ## content.js

// This module provides functions to convert the shogiplayground
// (https://play.mogproject.com/) format to KIF.

(() => {
  const sidebar = document.querySelector("div.sidebar-left-content");
  if (!sidebar) {
    alert("Sidebar not found!");
    return;
  }

  const branchSelect = sidebar.querySelector("select");
  const copyButton = sidebar.querySelector("button");
  if (!branchSelect || !copyButton) {
    alert("Branch selector or copy button not found!");
    return;
  }

  const results = [];

  const collectMoves = async () => {
    for (let i = 0; i < branchSelect.options.length; i++) {
      branchSelect.selectedIndex = i;
      branchSelect.dispatchEvent(new Event("change"));
      await new Promise(r => setTimeout(r, 200));

      const text = copyButton.getAttribute("data-clipboard-text") || "";
      let prevDest = null;
      const lines = text.split("\n").map(l => {
        const kif = toKIF(l, prevDest);
        if (kif) {
          const match = kif.match(/^[▲△](同|\d[一二三四五六七八九])/);
          if (match) prevDest = match[1] === "同" ? prevDest : match[0].slice(1);
        }
        return kif;
      }).filter(Boolean);

      const label = branchSelect.options[i].textContent.trim();
      results.push(`${label}:\n${lines.join("\n")}`);
    }
  };

  const default_filename = "shogiplayground-plugin.kif";

  collectMoves().then(() => {
    const finalText = results.join("\n\n");
    const blob = new Blob([finalText], { type: "text/plain" });
    const url = URL.createObjectURL(blob);
    const a = document.createElement("a");
    a.href = url;
    a.download = default_filename;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);

    alert(`All branches exported to ${default_filename}!`);
  });
})();