// Copyright 2022 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flags: --experimental-wasm-stringref

d8.file.execute("test/mjsunit/wasm/wasm-module-builder.js");

let kSig_w_ii = makeSig([kWasmI32, kWasmI32], [kWasmStringRef]);

function encodeWtf8(str) {
  // String iterator coalesces surrogate pairs.
  let out = [];
  for (let codepoint of str) {
    codepoint = codepoint.codePointAt(0);
    if (codepoint <= 0x7f) {
      out.push(codepoint);
    } else if (codepoint <= 0x7ff) {
      out.push(0xc0 | (codepoint >> 6));
      out.push(0x80 | (codepoint & 0x3f));
    } else if (codepoint <= 0xffff) {
      out.push(0xe0 | (codepoint >> 12));
      out.push(0x80 | ((codepoint >> 6) & 0x3f));
      out.push(0x80 | (codepoint & 0x3f));
    } else if (codepoint <= 0x10ffff) {
      out.push(0xf0 | (codepoint >> 18));
      out.push(0x80 | ((codepoint >> 12) & 0x3f));
      out.push(0x80 | ((codepoint >> 6) & 0x3f));
      out.push(0x80 | (codepoint & 0x3f));
    } else {
      throw new Error("bad codepoint " + codepoint);
    }
  }
  return out;
}

function makeWtf8TestDataSegment() {
  let data = []
  let valid = {};
  let invalid = {};

  for (let str of ['',
                   'ascii',
                   'latin \xa9 1',
                   'two \ucccc byte',
                   'surrogate \ud800\udc000 pair',
                   'isolated \ud800 leading',
                   'isolated \udc00 trailing']) {
    let bytes = encodeWtf8(str);
    valid[str] = { offset: data.length, length: bytes.length };
    for (let byte of bytes) {
      data.push(byte);
    }
  }
  for (let bytes of ['trailing high byte \xa9',
                     'interstitial high \xa9 byte',
                     'invalid \xc0 byte',
                     'surrogate \xed\xa0\x80\xed\xd0\x80 pair']) {
    invalid[bytes] = { offset: data.length, length: bytes.length };
    for (let i = 0; i < bytes.length; i++) {
      data.push(bytes.charCodeAt(i));
    }
  }

  return { valid, invalid, data: Uint8Array.from(data) };
};

(function TestStringNewWtf8() {
  let builder = new WasmModuleBuilder();

  builder.addMemory(1, undefined, false, false);
  let data = makeWtf8TestDataSegment();
  builder.addDataSegment(0, data.data);

  builder.addFunction("string_new_wtf8", kSig_w_ii)
    .exportAs("string_new_wtf8")
    .addBody([
      kExprLocalGet, 0, kExprLocalGet, 1,
      kGCPrefix, kExprStringNewWtf8, 0
    ]);

  let instance = builder.instantiate();
  for (let [str, {offset, length}] of Object.entries(data.valid)) {
    assertEquals(str, instance.exports.string_new_wtf8(offset, length));
  }
  for (let [str, {offset, length}] of Object.entries(data.invalid)) {
    assertThrows(() => instance.exports.string_new_wtf8(offset, length),
                 WebAssembly.RuntimeError, "invalid WTF-8 string");
  }
})();

function encodeWtf16LE(str) {
  // String iterator coalesces surrogate pairs.
  let out = [];
  for (let i = 0; i < str.length; i++) {
    codeunit = str.charCodeAt(i);
    out.push(codeunit & 0xff)
    out.push(codeunit >> 8);
  }
  return out;
}

function makeWtf16TestDataSegment() {
  let data = []
  let valid = {};

  for (let str of ['',
                   'ascii',
                   'latin \xa9 1',
                   'two \ucccc byte',
                   'surrogate \ud800\udc000 pair',
                   'isolated \ud800 leading',
                   'isolated \udc00 trailing']) {
    valid[str] = { offset: data.length, length: str.length };
    for (let byte of encodeWtf16LE(str)) {
      data.push(byte);
    }
  }

  return { valid, data: Uint8Array.from(data) };
};

(function TestStringNewWtf16() {
  let builder = new WasmModuleBuilder();

  builder.addMemory(1, undefined, false, false);
  let data = makeWtf16TestDataSegment();
  builder.addDataSegment(0, data.data);

  builder.addFunction("string_new_wtf16", kSig_w_ii)
    .exportAs("string_new_wtf16")
    .addBody([
      kExprLocalGet, 0, kExprLocalGet, 1,
      kGCPrefix, kExprStringNewWtf16, 0
    ]);

  let instance = builder.instantiate();
  for (let [str, {offset, length}] of Object.entries(data.valid)) {
    assertEquals(str, instance.exports.string_new_wtf16(offset, length));
  }
})();