// wasm2js.js - enough of a polyfill for the WebAssembly object so that we can load
// wasm2js code that way. Similar to the same file in emscripten, but tailored for
// fuzzing purposes here.

var WebAssembly = {
  Memory: function(opts) {
    return {
      buffer: new ArrayBuffer(opts['initial'] * 64 * 1024),
      grow: function(amount) {
        var oldBuffer = this.buffer;
        var ret = __growWasmMemory(amount);
        assert(this.buffer !== oldBuffer); // the call should have updated us
        return ret;
      }
    };
  },

  Table: function(opts) {
    var ret = new Array(opts['initial']);
    ret.grow = function(by) {
      ret.push(null);
    };
    ret.set = function(i, func) {
      ret[i] = func;
    };
    ret.get = function(i) {
      return ret[i];
    };
    return ret;
  },

  Module: function(binary) {
    // TODO: use the binary and info somehow - right now the wasm2js output is embedded in
    // the main JS
    return {};
  },

  Instance: function(module, info) {
    // TODO: use the module and info somehow - right now the wasm2js output is embedded in
    // the main JS
    var decodeBase64 = typeof atob === 'function' ? atob : function (input) {
      var keyStr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';

      var output = '';
      var chr1, chr2, chr3;
      var enc1, enc2, enc3, enc4;
      var i = 0;
      // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
      input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '');
      do {
        enc1 = keyStr.indexOf(input.charAt(i++));
        enc2 = keyStr.indexOf(input.charAt(i++));
        enc3 = keyStr.indexOf(input.charAt(i++));
        enc4 = keyStr.indexOf(input.charAt(i++));

        chr1 = (enc1 << 2) | (enc2 >> 4);
        chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
        chr3 = ((enc3 & 3) << 6) | enc4;

        output = output + String.fromCharCode(chr1);

        if (enc3 !== 64) {
          output = output + String.fromCharCode(chr2);
        }
        if (enc4 !== 64) {
          output = output + String.fromCharCode(chr3);
        }
      } while (i < input.length);
      return output;
    };
    var atob = decodeBase64;
    // Additional imports
    asmLibraryArg['__tempMemory__'] = 0; // risky!
    // This will be replaced by the actual wasm2js code.
    var exports = instantiate(asmLibraryArg, wasmMemory, wasmTable);
    return {
      'exports': exports
    };
  },

  instantiate: function(binary, info) {
    return {
      then: function(ok, err) {
        ok({
          'instance': new WebAssembly.Instance(new WebAssembly.Module(binary, info))
        });
      }
    };
  }
};

var asmLibraryArg = {
};

var wasmMemory = new WebAssembly.Memory({ initial: 1 });
var wasmTable = new WebAssembly.Table({ initial: 1 });