/**
 * AKSRT Weixin Share
 *
 * Bridge-first WeChat share helper with QR fallback.
 *
 * @package AKSRT
 */

(function () {
  'use strict';

  /**
   * Local QR code data URL generator — no third-party services.
   * Uses canvas rendering with a minimal QR matrix encoder.
   */
  function buildQRCodeDataUrl(text, size) {
    size = size || 160;
    try {
      var matrix = generateQRMatrix(text || ' ');
      if (!matrix) return '';
      var canvas = document.createElement('canvas');
      var moduleCount = matrix.length;
      var scale = Math.floor(size / (moduleCount + 8));
      var margin = Math.floor((size - scale * moduleCount) / 2);
      canvas.width = size;
      canvas.height = size;
      var ctx = canvas.getContext('2d');
      ctx.fillStyle = '#ffffff';
      ctx.fillRect(0, 0, size, size);
      ctx.fillStyle = '#000000';
      for (var r = 0; r < moduleCount; r++) {
        for (var c = 0; c < moduleCount; c++) {
          if (matrix[r][c]) {
            ctx.fillRect(margin + c * scale, margin + r * scale, scale, scale);
          }
        }
      }
      return canvas.toDataURL('image/png');
    } catch (e) {
      return '';
    }
  }

  /**
   * Minimal QR Code matrix generator (Version 1-6, Byte mode, Error Correction L).
   * Returns a 2D boolean array or null on failure.
   */
  function generateQRMatrix(text) {
    var data = encodeUTF8(text);
    // Choose version based on data length (EC level L, Byte mode)
    var version = 1;
    var capacities = [0, 17, 32, 53, 78, 106, 134];
    for (var v = 1; v <= 6; v++) {
      if (data.length <= capacities[v]) { version = v; break; }
      if (v === 6) return null; // data too long for small versions
    }
    var moduleCount = version * 4 + 17;
    var matrix = createMatrix(moduleCount);
    var reserved = createMatrix(moduleCount);

    // Place finder patterns
    placeFinder(matrix, reserved, 0, 0);
    placeFinder(matrix, reserved, moduleCount - 7, 0);
    placeFinder(matrix, reserved, 0, moduleCount - 7);

    // Place alignment patterns (version >= 2)
    if (version >= 2) {
      var alignPos = getAlignmentPositions(version);
      for (var i = 0; i < alignPos.length; i++) {
        for (var j = 0; j < alignPos.length; j++) {
          if (isInFinder(alignPos[i], alignPos[j], moduleCount)) continue;
          placeAlignment(matrix, reserved, alignPos[i], alignPos[j]);
        }
      }
    }

    // Place timing patterns
    for (var i = 8; i < moduleCount - 8; i++) {
      if (!reserved[6][i]) { matrix[6][i] = (i % 2 === 0); reserved[6][i] = true; }
      if (!reserved[i][6]) { matrix[i][6] = (i % 2 === 0); reserved[i][6] = true; }
    }

    // Reserve format info areas
    for (var i = 0; i < 8; i++) {
      reserved[8][i] = true; reserved[i][8] = true;
      reserved[8][moduleCount - 1 - i] = true; reserved[moduleCount - 1 - i][8] = true;
    }
    reserved[8][8] = true;
    if (version >= 2) {
      for (var i = moduleCount - 11; i < moduleCount - 8; i++) {
        for (var j = 0; j < 6; j++) { reserved[j][i] = true; reserved[i][j] = true; }
      }
    }

    // Dark module
    matrix[moduleCount - 8][8] = true;
    reserved[moduleCount - 8][8] = true;

    // Encode data
    var dataBits = encodeData(data, version);
    placeData(matrix, reserved, dataBits, moduleCount);

    // Apply best mask
    var bestMask = 0;
    var bestPenalty = Infinity;
    for (var m = 0; m < 8; m++) {
      var masked = applyMask(matrix, reserved, m, moduleCount);
      var penalty = calcPenalty(masked, moduleCount);
      if (penalty < bestPenalty) { bestPenalty = penalty; bestMask = m; }
    }
    matrix = applyMask(matrix, reserved, bestMask, moduleCount);

    // Place format info
    placeFormatInfo(matrix, bestMask, moduleCount);

    return matrix;
  }

  function createMatrix(n) {
    var m = [];
    for (var i = 0; i < n; i++) { m[i] = []; for (var j = 0; j < n; j++) m[i][j] = false; }
    return m;
  }

  function encodeUTF8(str) {
    var bytes = [];
    for (var i = 0; i < str.length; i++) {
      var c = str.charCodeAt(i);
      if (c < 0x80) bytes.push(c);
      else if (c < 0x800) { bytes.push(0xc0 | (c >> 6)); bytes.push(0x80 | (c & 0x3f)); }
      else { bytes.push(0xe0 | (c >> 12)); bytes.push(0x80 | ((c >> 6) & 0x3f)); bytes.push(0x80 | (c & 0x3f)); }
    }
    return bytes;
  }

  function placeFinder(m, r, row, col) {
    for (var dr = -1; dr <= 7; dr++) {
      for (var dc = -1; dc <= 7; dc++) {
        var rr = row + dr, cc = col + dc;
        if (rr < 0 || rr >= m.length || cc < 0 || cc >= m.length) continue;
        var val = (dr >= 0 && dr <= 6 && (dc === 0 || dc === 6)) || (dc >= 0 && dc <= 6 && (dr === 0 || dr === 6)) || (dr >= 2 && dr <= 4 && dc >= 2 && dc <= 4);
        m[rr][cc] = val;
        r[rr][cc] = true;
      }
    }
  }

  function placeAlignment(m, r, row, col) {
    for (var dr = -2; dr <= 2; dr++) {
      for (var dc = -2; dc <= 2; dc++) {
        var val = Math.abs(dr) === 2 || Math.abs(dc) === 2 || (dr === 0 && dc === 0);
        m[row + dr][col + dc] = val;
        r[row + dr][col + dc] = true;
      }
    }
  }

  function getAlignmentPositions(v) {
    if (v <= 1) return [];
    if (v === 2) return [6, 18];
    if (v === 3) return [6, 22];
    if (v === 4) return [6, 26];
    if (v === 5) return [6, 30];
    return [6, 34];
  }

  function isInFinder(row, col, n) {
    return (row < 9 && col < 9) || (row < 9 && col >= n - 8) || (row >= n - 8 && col < 9);
  }

  function encodeData(data, version) {
    var bits = [];
    // Mode indicator: Byte = 0100
    bits.push(0, 1, 0, 0);
    // Character count
    var ccBits = version <= 9 ? 8 : 16;
    for (var i = ccBits - 1; i >= 0; i--) bits.push((data.length >> i) & 1);
    // Data
    for (var i = 0; i < data.length; i++) {
      for (var j = 7; j >= 0; j--) bits.push((data[i] >> j) & 1);
    }
    // Terminator
    var capacities = [0, 152, 272, 440, 640, 864, 1088];
    var cap = capacities[version] || 152;
    for (var i = 0; i < 4 && bits.length < cap; i++) bits.push(0);
    // Pad to byte boundary
    while (bits.length % 8 !== 0) bits.push(0);
    // Pad bytes
    var padBytes = [0xEC, 0x11];
    var pi = 0;
    while (bits.length < cap) {
      var pb = padBytes[pi % 2];
      for (var j = 7; j >= 0; j--) bits.push((pb >> j) & 1);
      pi++;
    }
    return bits;
  }

  function placeData(matrix, reserved, bits, n) {
    var bitIndex = 0;
    for (var right = n - 1; right >= 1; right -= 2) {
      if (right === 6) right = 5;
      for (var vert = 0; vert < n; vert++) {
        for (var j = 0; j < 2; j++) {
          var col = right - j;
          var upward = ((right + 1) & 2) === 0;
          var row = upward ? n - 1 - vert : vert;
          if (!reserved[row][col] && bitIndex < bits.length) {
            matrix[row][col] = bits[bitIndex] === 1;
            bitIndex++;
          }
        }
      }
    }
  }

  function applyMask(matrix, reserved, maskNum, n) {
    var result = createMatrix(n);
    for (var r = 0; r < n; r++) {
      for (var c = 0; c < n; c++) {
        result[r][c] = matrix[r][c];
        if (!reserved[r][c]) {
          var invert = false;
          switch (maskNum) {
            case 0: invert = (r + c) % 2 === 0; break;
            case 1: invert = r % 2 === 0; break;
            case 2: invert = c % 3 === 0; break;
            case 3: invert = (r + c) % 3 === 0; break;
            case 4: invert = (Math.floor(r / 2) + Math.floor(c / 3)) % 2 === 0; break;
            case 5: invert = (r * c) % 2 + (r * c) % 3 === 0; break;
            case 6: invert = ((r * c) % 2 + (r * c) % 3) % 2 === 0; break;
            case 7: invert = ((r + c) % 2 + (r * c) % 3) % 2 === 0; break;
          }
          if (invert) result[r][c] = !result[r][c];
        }
      }
    }
    return result;
  }

  function calcPenalty(matrix, n) {
    var penalty = 0;
    // Rule 1: consecutive same-color modules in row/column
    for (var r = 0; r < n; r++) {
      var run = 1;
      for (var c = 1; c < n; c++) {
        if (matrix[r][c] === matrix[r][c - 1]) { run++; } else { run = 1; }
        if (run === 5) penalty += 3;
        else if (run > 5) penalty += 1;
      }
    }
    for (var c = 0; c < n; c++) {
      var run = 1;
      for (var r = 1; r < n; r++) {
        if (matrix[r][c] === matrix[r - 1][c]) { run++; } else { run = 1; }
        if (run === 5) penalty += 3;
        else if (run > 5) penalty += 1;
      }
    }
    return penalty;
  }

  function placeFormatInfo(matrix, maskNum, n) {
    var formatInfo = getFormatInfo(maskNum);
    // Place around top-left finder
    var positions = [
      [8, 0], [8, 1], [8, 2], [8, 3], [8, 4], [8, 5], [8, 7], [8, 8],
      [7, 8], [5, 8], [4, 8], [3, 8], [2, 8], [1, 8], [0, 8]
    ];
    for (var i = 0; i < 15; i++) {
      var r = positions[i][0], c = positions[i][1];
      matrix[r][c] = formatInfo[i] === 1;
    }
    // Place around bottom-left and top-right finders
    var positions2 = [
      [n - 1, 8], [n - 2, 8], [n - 3, 8], [n - 4, 8], [n - 5, 8], [n - 6, 8], [n - 7, 8],
      [8, n - 8], [8, n - 7], [8, n - 6], [8, n - 5], [8, n - 4], [8, n - 3], [8, n - 2], [8, n - 1]
    ];
    for (var i = 0; i < 15; i++) {
      var r = positions2[i][0], c = positions2[i][1];
      matrix[r][c] = formatInfo[i] === 1;
    }
  }

  function getFormatInfo(maskNum) {
    // EC level L = 01, mask number = maskNum
    var data = (0x01 << 3) | maskNum; // 5 bits
    var bits = data << 10;
    // BCH(15,5) error correction
    var gen = 0x537; // generator polynomial
    for (var i = 14; i >= 10; i--) {
      if (bits & (1 << i)) bits ^= gen << (i - 10);
    }
    var formatBits = (data << 10) | bits;
    // XOR with mask pattern
    formatBits ^= 0x5412;
    var result = [];
    for (var i = 14; i >= 0; i--) result.push((formatBits >> i) & 1);
    return result;
  }

  function isWeixinEnv() {
    return /micromessenger/i.test(window.navigator.userAgent || '') || !!window.WeixinJSBridge;
  }

  function normalizePayload(payload) {
    payload = payload || {};
    return {
      title: payload.title || document.title,
      url: payload.url || window.location.href,
      desc: payload.desc || '',
      image: payload.image || ''
    };
  }

  function hideQrFallback(qrBox) {
    if (!qrBox) return;
    qrBox.classList.remove('is-visible');
    qrBox.setAttribute('aria-hidden', 'true');
  }

  function showQrFallback(payload) {
    var qrBox = payload.qrBox;
    var qrImage = payload.qrImage;
    if (!qrBox || !qrImage || !payload.url) {
      return Promise.resolve({
        mode: 'error',
        message: '当前页面缺少微信二维码容器'
      });
    }

    if (qrImage.dataset.qrValue !== payload.url || !qrImage.getAttribute('src')) {
      qrImage.dataset.qrValue = payload.url;
      var dataUrl = buildQRCodeDataUrl(payload.url, 160);
      if (dataUrl) {
        qrImage.src = dataUrl;
      } else {
        qrImage.alt = '二维码生成失败，请直接复制链接分享';
      }
    }

    qrBox.classList.add('is-visible');
    qrBox.setAttribute('aria-hidden', 'false');

    return Promise.resolve({
      mode: 'qr',
      message: '请使用微信扫一扫分享'
    });
  }

  function bridgeWithWxSdk(payload) {
    return new Promise(function (resolve, reject) {
      if (!window.wx || typeof window.wx.ready !== 'function') {
        reject(new Error('wx sdk unavailable'));
        return;
      }

      var done = false;
      var timer = window.setTimeout(function () {
        if (done) return;
        done = true;
        reject(new Error('微信分享桥接未就绪'));
      }, 1200);

      function finishSuccess() {
        if (done) return;
        done = true;
        window.clearTimeout(timer);
        resolve({
          mode: 'bridge',
          message: '已同步微信分享信息，请使用右上角菜单继续分享'
        });
      }

      function finishError(error) {
        if (done) return;
        done = true;
        window.clearTimeout(timer);
        reject(error instanceof Error ? error : new Error('微信分享桥接失败'));
      }

      try {
        if (typeof window.wx.error === 'function') {
          window.wx.error(function (error) {
            finishError(new Error((error && error.errMsg) || '微信签名校验失败'));
          });
        }

        window.wx.ready(function () {
          try {
            if (typeof window.wx.updateAppMessageShareData === 'function') {
              window.wx.updateAppMessageShareData({
                title: payload.title,
                desc: payload.desc,
                link: payload.url,
                imgUrl: payload.image
              });
            }

            if (typeof window.wx.updateTimelineShareData === 'function') {
              window.wx.updateTimelineShareData({
                title: payload.title,
                link: payload.url,
                imgUrl: payload.image
              });
            }

            finishSuccess();
          } catch (error) {
            finishError(error);
          }
        });
      } catch (error) {
        finishError(error);
      }
    });
  }

  function bridgeWithWeixinJsBridge(payload) {
    return new Promise(function (resolve, reject) {
      var bridge = window.WeixinJSBridge;
      if (!bridge || typeof bridge.invoke !== 'function') {
        reject(new Error('WeixinJSBridge unavailable'));
        return;
      }

      try {
        bridge.invoke('sendAppMessage', {
          title: payload.title,
          desc: payload.desc,
          link: payload.url,
          img_url: payload.image
        }, function (response) {
          var errMsg = response && response.err_msg ? response.err_msg : '';
          if (!errMsg || /:ok$/i.test(errMsg)) {
            resolve({
              mode: 'bridge',
              message: '已调起微信分享面板'
            });
            return;
          }

          reject(new Error(errMsg));
        });
      } catch (error) {
        reject(error);
      }
    });
  }

  function openWeixinShare(payload) {
    var data = normalizePayload(payload);
    data.qrBox = payload && payload.qrBox ? payload.qrBox : null;
    data.qrImage = payload && payload.qrImage ? payload.qrImage : null;

    if (!isWeixinEnv()) {
      return showQrFallback(data);
    }

    return bridgeWithWxSdk(data)
      .catch(function () {
        return bridgeWithWeixinJsBridge(data);
      })
      .catch(function (error) {
        return showQrFallback(data).then(function (result) {
          result.message = (error && error.message ? error.message + '，' : '') + '已切换为二维码分享';
          return result;
        });
      });
  }

  window.AksrtShare = Object.assign({}, window.AksrtShare || {}, {
    isWeixinEnv: isWeixinEnv,
    hideQrFallback: hideQrFallback,
    showQrFallback: showQrFallback,
    openWeixinShare: openWeixinShare,
    // Exposed so the unified share-data-builder can render poster QR codes
    // without a second encoder.
    buildQrDataUrl: buildQRCodeDataUrl
  });
})();