const fs = require("fs");
const path = require("path");
const chalk = require("chalk");
const glob = require("glob");
const diff = require("./util/diff");

require("ts-node").register({ project: require("path").join(__dirname, "..", "src") });
require("../src/glue/js");

const { Compiler, Options } = require("../src/compiler");
const { Module } = require("../src/module");
const { Parser } = require("../src/parser");
const { ElementKind, LIBRARY_PREFIX } = require("../src/program");

var isCreate = process.argv[2] === "--create";
var filter = process.argv.length > 2 && !isCreate ? "**/" + process.argv[2] + ".ts" : "**/*.ts";

var stdDir = path.join(__dirname, "..", "std", "assembly");
var stdFiles = glob.sync("*.ts", { cwd: stdDir });

var success = 0;
var failures = 0;

glob.sync(filter, { cwd: path.join(__dirname, "compiler") }).forEach(filename => {
  if (filename.charAt(0) == "_") return;
  console.log(chalk.whiteBright("Testing compiler/" + filename));

  var fixture = path.basename(filename, ".ts");
  var startTime = process.hrtime();
  var parser = new Parser();
  var cwd = path.join(__dirname, "compiler");

  // include stdlib in std/ tests only. doing this to reduce the sheer amount of
  // program elements listed at the bottom of the basic fixtures.
  if (filename.startsWith("std/")) {
    stdFiles.forEach(file => parser.parseFile(fs.readFileSync(path.join(stdDir, file), { encoding: "utf8" }), LIBRARY_PREFIX + path.basename(file), false));
    fixture = "std/" + fixture;
  }

  var sourceText = fs.readFileSync(path.join(cwd, filename), { encoding: "utf8" });
  parser.parseFile(sourceText, filename, true);
  var nextFile;
  while ((nextFile = parser.nextFile()) !== null) {
    if (nextFile.startsWith(LIBRARY_PREFIX)) {
      sourceText = fs.readFileSync(path.join(stdDir, nextFile.substring(LIBRARY_PREFIX.length) + ".ts"), { encoding: "utf8" });
      nextFile = nextFile + ".ts";
    } else {
      try {
        sourceText = fs.readFileSync(path.join(cwd, nextFile + ".ts"), { encoding: "utf8" });
        nextFile += ".ts";
      } catch (e) {
        try {
          sourceText = fs.readFileSync(path.join(cwd, nextFile, "index.ts"), { encoding: "utf8" });
          nextFile += "/index.ts";
        } catch (e) {
          sourceText = fs.readFileSync(path.join(stdDir, nextFile + ".ts"), { encoding: "utf8" });
          nextFile = LIBRARY_PREFIX + nextFile + ".ts";
          // FIXME: what exactly is swallowing the error here?
        }
      }
    }
    parser.parseFile(sourceText, nextFile, false);
  }
  var program = parser.finish();
  var options = new Options();
  options.sourceMap = true;
  var parseTime = process.hrtime(startTime);
  startTime = process.hrtime();
  var module;
  try {
    module = Compiler.compile(program, options);
  } catch (e) {
    failed = true;
    module = Module.create();
    console.log(chalk.red("compile ERROR: ") + e.stack);
  }
  var compileTime = process.hrtime(startTime);
  var actual = module.toText() + "(;\n[program.elements]\n  " + elements(program.elements)
                               +   "\n[program.exports]\n  "  + elements(program.exports)
                               + "\n;)\n";
  var actualOptimized = null;

  console.log("parse incl. I/O: " + ((parseTime[0] * 1e9 + parseTime[1]) / 1e6).toFixed(3) + "ms / compile: " + ((compileTime[0] * 1e9 + compileTime[1]) / 1e6).toFixed(3) + "ms");

  var failed = false;
  if (module.validate()) {
    console.log(chalk.green("validate OK"));
    try {
      var binary = module.toBinary();
      var wasmModule = new WebAssembly.Module(binary.output);
      var wasmInstance = new WebAssembly.Instance(wasmModule, {
        env: {
          abort: function(msg, file, line, column) {
            throw new Error("Assertion failed");
          },
          externalFunc: function(arg0, arg1, arg2) {
            console.log("env.externalFunc called with: " + arg0 + ", " + arg1 + ", " + arg2);
          },
          externalConst: 1,
          allocate_memory: function(size) {
            console.log("env.allocate_memory called with: " + size);
            return 0;
          },
          free_memory: function(ptr) {
            console.log("env.free_memory called with: " + ptr);
          }
        },
        external: {
          externalFunc: function(arg0, arg1, arg2) {
            console.log("external.externalFunc called with: " + arg0 + ", " + arg1 + ", " + arg2);
          },
          externalConst: 2
        }
      });
      console.log(chalk.green("instantiate OK"));
    } catch (e) {
      failed = true;
      console.log(chalk.red("instantiate ERROR: ") + e.stack);
    }
    module.optimize();
    actualOptimized = module.toText();
    if (isCreate) {
      var binary = module.toBinary(fixture + ".optimized.wasm.map");
      fs.writeFileSync(__dirname + "/compiler/" + fixture + ".optimized.wasm", binary.output);
      if (binary.sourceMap != null)
        fs.writeFileSync(__dirname + "/compiler/" + fixture + ".optimized.wasm.map", binary.sourceMap, { encoding: "utf8" });
    }
  } else {
    failed = true;
    console.log(chalk.red("validate ERROR"));
  }

  if (isCreate) {
    fs.writeFileSync(__dirname + "/compiler/" + fixture + ".wast", actual, { encoding: "utf8" });
    console.log("Created");
    if (actualOptimized != null) {
      fs.writeFileSync(__dirname + "/compiler/" + fixture + ".optimized.wast", actualOptimized, { encoding: "utf8" });
      console.log("Created optimized");
    }
  } else {
    var expected;
    try {
      expected = fs.readFileSync(__dirname + "/compiler/" + fixture + ".wast", { encoding: "utf8" });
    } catch (e) {
      expected = e.message + "\n";
    }
    var diffs = diff(filename + ".wast", expected, actual);
    if (diffs !== null) {
      console.log(diffs);
      console.log(chalk.red("diff ERROR"));
      failed = true;
    } else
      console.log(chalk.green("diff OK"));
  }

  module.dispose();
  console.log();
  if (failed)
    ++failures;
});

function elements(map) {
  var arr = [];
  map.forEach((value, key) => {
    arr.push(ElementKind[value.kind] + ": " + key);
  });
  return arr.join("\n  ");
}

if (failures) {
  process.exitCode = 1;
  console.log(chalk.red("ERROR: ") + failures + " compiler tests failed");
} else
  console.log("[ " + chalk.whiteBright("SUCCESS") + " ]");