// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
(() => {
	// Map multiple JavaScript environments to a single common API,
	// preferring web standards over Node.js API.
	//
	// Environments considered:
	// - Browsers
	// - Node.js
	// - Electron
	// - Parcel
	// - Webpack

	console.log("imported")
	if (typeof global !== "undefined") {
		// global already exists
	} else if (typeof window !== "undefined") {
		window.global = window;
	} else if (typeof self !== "undefined") {
		self.global = self;
	} else {
		throw new Error("cannot export Go (neither global, window nor self is defined)");
	}

	let logFS = false
	var handler = {
		get: function (target, property) {
			if (property in target && target[property] instanceof Function) {
				return function () {
					if (logFS) {
						console.log(property, 'called', arguments);
					}
					// 将callback替换
					if (arguments[arguments.length - 1] instanceof Function) {
						var origCB = arguments[arguments.length - 1];
						var newCB = function () {
							if (logFS) {
								console.log('callback for', property, 'get called with args:', arguments);
							}
							return Reflect.apply(origCB, arguments.callee, arguments);
						}
						arguments[arguments.length - 1] = newCB;
					}
					return Reflect.apply(target[property], target, arguments);
				}
			} else {
				return target[property]
			}
		}
	}

	if (!global.require && typeof require !== "undefined") {
		global.require = require;
	}


	if (!global.fs && global.require) {

		//const fs = require("fs");
		if (typeof fs === "object" && fs !== null && Object.keys(fs).length !== 0) {
			global.fs = fs;
		}

	}

	const enosys = () => {
		const err = new Error("not implemented");
		err.code = "ENOSYS";
		return err;
	};

	if (!global.fs) {
		let outputBuf = "";
		global.fs = {
			constants: {
				O_WRONLY: -1,
				O_RDWR: -1,
				O_CREAT: -1,
				O_TRUNC: -1,
				O_APPEND: -1,
				O_EXCL: -1
			}, // unused
			writeSync(fd, buf) {
				outputBuf += decoder.decode(buf);
				const nl = outputBuf.lastIndexOf("\n");
				if (nl != -1) {
					console.log(outputBuf.substr(0, nl));
					outputBuf = outputBuf.substr(nl + 1);
				}
				return buf.length;
			},
			write(fd, buf, offset, length, position, callback) {
				if (offset !== 0 || length !== buf.length || position !== null) {
					callback(enosys());
					return;
				}
				const n = this.writeSync(fd, buf);
				callback(null, n);
			},
			chmod(path, mode, callback) {
				callback(enosys());
			},
			chown(path, uid, gid, callback) {
				callback(enosys());
			},
			close(fd, callback) {
				callback(enosys());
			},
			fchmod(fd, mode, callback) {
				callback(enosys());
			},
			fchown(fd, uid, gid, callback) {
				callback(enosys());
			},
			fstat(fd, callback) {
				callback(enosys());
			},
			fsync(fd, callback) {
				callback(null);
			},
			ftruncate(fd, length, callback) {
				callback(enosys());
			},
			lchown(path, uid, gid, callback) {
				callback(enosys());
			},
			link(path, link, callback) {
				callback(enosys());
			},
			lstat(path, callback) {
				callback(enosys());
			},
			mkdir(path, perm, callback) {
				callback(enosys());
			},
			open(path, flags, mode, callback) {
				callback(enosys());
			},
			read(fd, buffer, offset, length, position, callback) {
				callback(enosys());
			},
			readdir(path, callback) {
				callback(enosys());
			},
			readlink(path, callback) {
				callback(enosys());
			},
			rename(from, to, callback) {
				callback(enosys());
			},
			rmdir(path, callback) {
				callback(enosys());
			},
			stat(path, callback) {
				callback(enosys());
			},
			symlink(path, link, callback) {
				callback(enosys());
			},
			truncate(path, length, callback) {
				callback(enosys());
			},
			unlink(path, callback) {
				callback(enosys());
			},
			utimes(path, atime, mtime, callback) {
				callback(enosys());
			},
		};
	}

	if (!global.process) {
		global.process = {
			getuid() {
				return -1;
			},
			getgid() {
				return -1;
			},
			geteuid() {
				return -1;
			},
			getegid() {
				return -1;
			},
			getgroups() {
				throw enosys();
			},
			pid: -1,
			ppid: -1,
			umask() {
				throw enosys();
			},
			cwd() {
				throw enosys();
			},
			chdir() {
				throw enosys();
			},
		}
	}

	if (!global.crypto && global.require) {
		const nodeCrypto = require("crypto");
		global.crypto = {
			getRandomValues(b) {
				nodeCrypto.randomFillSync(b);
			},
		};
	}
	if (!global.crypto) {
		throw new Error("global.crypto is not available, polyfill required (getRandomValues only)");
	}

	if (!global.performance) {
		global.performance = {
			now() {
				const [sec, nsec] = process.hrtime();
				return sec * 1000 + nsec / 1000000;
			},
		};
	}

	if (!global.TextEncoder && global.require) {
		global.TextEncoder = require("util").TextEncoder;
	}
	if (!global.TextEncoder) {
		throw new Error("global.TextEncoder is not available, polyfill required");
	}

	if (!global.TextDecoder && global.require) {
		global.TextDecoder = require("util").TextDecoder;
	}
	if (!global.TextDecoder) {
		throw new Error("global.TextDecoder is not available, polyfill required");
	}


	const isNodeJS = global.process && global.process.title === "node";

	if (!isNodeJS) {
		// console.log("ini browser fs")
		// var myfs = global.BrowserFS.BFSRequire('fs');
		// global.Buffer = global.BrowserFS.BFSRequire('buffer').Buffer;
		// global.fs = myfs;

		global.fs.constants = {
			O_RDONLY: 0,
			O_WRONLY: 1,
			O_RDWR: 2,
			O_CREAT: 64,
			O_CREATE: 64,
			O_EXCL: 128,
			O_NOCTTY: 256,
			O_TRUNC: 512,
			O_APPEND: 1024,
			O_DIRECTORY: 65536,
			O_NOATIME: 262144,
			O_NOFOLLOW: 131072,
			O_SYNC: 1052672,
			O_DIRECT: 16384,
			O_NONBLOCK: 2048,
		};

		let outputBuf = "";

		global.fs.writeSyncOriginal = global.fs.writeSync
		global.fs.writeSync = function (fd, buf) {
			if (fd === 1 || fd === 2) {
				outputBuf += decoder.decode(buf);
				const nl = outputBuf.lastIndexOf("\n");
				if (nl != -1) {
					console.log(outputBuf.substr(0, nl));
					outputBuf = outputBuf.substr(nl + 1);
				}
				return buf.length;
			} else {
				return global.fs.writeSyncOriginal(...arguments);
			}
		};

		global.fs.writeOriginal = global.fs.write
		global.fs.write = function (fd, buf, offset, length, position, callback) {
			// (corresponding to STDOUT/STDERR)
			if (fd === 1 || fd === 2) {
				if (offset !== 0 || length !== buf.length || position !== null) {
					throw new Error("not implemented");
				}
				const n = this.writeSync(fd, buf);
				callback(null, n, buf);
			} else {
				// buf: read buf first
				arguments[1] = global.Buffer.from(arguments[1]);
				return global.fs.writeOriginal(...arguments);
			}
		};



		global.fs.openOriginal = global.fs.open
		global.fs.open = function (path, flags, mode, callback) {
			var myflags = 'r';
			var O = global.fs.constants;

			// Convert numeric flags to string flags
			// FIXME: maybe wrong...
			console.log("open dir?", path, 'flag', flags, myflags)
			if (flags & O.O_WRONLY) { // 'w'
				myflags = 'w';
				if (flags & O.O_EXCL) {
					myflags = 'wx';
				}
			} else if (flags & O.O_RDWR) { // 'r+' or 'w+'
				if (flags & O.O_CREAT && flags & O.O_TRUNC) { // w+
					if (flags & O.O_EXCL) {
						myflags = 'wx+';
					} else {
						myflags = 'w+';
					}
				} else { // r+
					myflags = 'r+';
				}
			} else if (flags & O.O_APPEND) { // 'a'
				console.log("append error")
				throw new Error("Not implmented");
			} else {
				// 打开文件
				myflags = 'r+';
				console.log("open dir?", path, 'flag', flags, myflags)
			}


			return global.fs.openOriginal(path, myflags, mode, callback);
		};

		global.fs.fstatOriginal = global.fs.fstat;
		global.fs.fstat = function (fd, callback) {
			return global.fs.fstatOriginal(fd, function () {
				var retStat = arguments[1];
				delete retStat['fileData'];
				retStat.atimeMs = retStat.atime.getTime();
				retStat.mtimeMs = retStat.mtime.getTime();
				retStat.ctimeMs = retStat.ctime.getTime();
				retStat.birthtimeMs = retStat.birthtime.getTime();
				return callback(arguments[0], retStat);

			});
		};



		global.fs.closeOriginal = global.fs.close;
		global.fs.close = function (fd, callback) {
			return global.fs.closeOriginal(fd, function () {
				if (typeof arguments[0] === 'undefined') arguments[0] = null;
				return callback(...arguments);
			});
		}

		// global.fs.renameOriginal = global.fs.rename
		// global.fs.rename = function (from, to, callback) {
		// 	console.log("rename a0", arguments[0])
		// 	global.fs.renameOriginal(from, to);
		// 	callback(arguments[0])
		// }

		// global.fs.renameSyncOriginal = global.fs.renameSync
		// global.fs.renameSync = function(fd, options) {
		// 	console.log("Sync")
		// }


		global.fs = new Proxy(global.fs, handler);
	}

	// End of polyfills for common API.

	const encoder = new TextEncoder("utf-8");
	const decoder = new TextDecoder("utf-8");

	global.Go = class {
		constructor() {
			this.argv = ["js"];
			this.env = {};
			this.exit = (code) => {
				this.exitCode = code;
				if (code !== 0) {
					console.warn("exit code:", code);
				}
			};
			this._exitPromise = new Promise((resolve) => {
				this._resolveExitPromise = resolve;
			});
			this._pendingEvent = null;
			this._scheduledTimeouts = new Map();
			this._nextCallbackTimeoutID = 1;

			const setInt64 = (addr, v) => {
				this.mem.setUint32(addr + 0, v, true);
				this.mem.setUint32(addr + 4, Math.floor(v / 4294967296), true);
			}

			const getInt64 = (addr) => {
				const low = this.mem.getUint32(addr + 0, true);
				const high = this.mem.getInt32(addr + 4, true);
				return low + high * 4294967296;
			}

			const loadValue = (addr) => {
				const f = this.mem.getFloat64(addr, true);
				if (f === 0) {
					return undefined;
				}
				if (!isNaN(f)) {
					return f;
				}

				const id = this.mem.getUint32(addr, true);
				return this._values[id];
			}

			const storeValue = (addr, v) => {
				const nanHead = 0x7FF80000;

				if (typeof v === "number" && v !== 0) {
					if (isNaN(v)) {
						this.mem.setUint32(addr + 4, nanHead, true);
						this.mem.setUint32(addr, 0, true);
						return;
					}
					this.mem.setFloat64(addr, v, true);
					return;
				}

				if (v === undefined) {
					this.mem.setFloat64(addr, 0, true);
					return;
				}

				let id = this._ids.get(v);
				if (id === undefined) {
					id = this._idPool.pop();
					if (id === undefined) {
						id = this._values.length;
					}
					this._values[id] = v;
					this._goRefCounts[id] = 0;
					this._ids.set(v, id);
				}
				this._goRefCounts[id]++;
				let typeFlag = 0;
				switch (typeof v) {
					case "object":
						if (v !== null) {
							typeFlag = 1;
						}
						break;
					case "string":
						typeFlag = 2;
						break;
					case "symbol":
						typeFlag = 3;
						break;
					case "function":
						typeFlag = 4;
						break;
				}
				this.mem.setUint32(addr + 4, nanHead | typeFlag, true);
				this.mem.setUint32(addr, id, true);
			}

			const loadSlice = (addr) => {
				const array = getInt64(addr + 0);
				const len = getInt64(addr + 8);
				return new Uint8Array(this._inst.exports.mem.buffer, array, len);
			}

			const loadSliceOfValues = (addr) => {
				const array = getInt64(addr + 0);
				const len = getInt64(addr + 8);
				const a = new Array(len);
				for (let i = 0; i < len; i++) {
					a[i] = loadValue(array + i * 8);
				}
				return a;
			}

			const loadString = (addr) => {
				const saddr = getInt64(addr + 0);
				const len = getInt64(addr + 8);
				return decoder.decode(new DataView(this._inst.exports.mem.buffer, saddr, len));
			}

			const timeOrigin = Date.now() - performance.now();
			this.importObject = {
				go: {
					// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
					// may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported
					// function. A goroutine can switch to a new stack if the current stack is too small (see morestack function).
					// This changes the SP, thus we have to update the SP used by the imported function.

					// func wasmExit(code int32)
					"runtime.wasmExit": (sp) => {
						sp >>>= 0;
						const code = this.mem.getInt32(sp + 8, true);
						this.exited = true;
						delete this._inst;
						delete this._values;
						delete this._goRefCounts;
						delete this._ids;
						delete this._idPool;
						this.exit(code);
					},

					// func wasmWrite(fd uintptr, p unsafe.Pointer, n int32)
					"runtime.wasmWrite": (sp) => {
						sp >>>= 0;
						const fd = getInt64(sp + 8);
						const p = getInt64(sp + 16);
						const n = this.mem.getInt32(sp + 24, true);
						fs.writeSync(fd, new Uint8Array(this._inst.exports.mem.buffer, p, n));
					},

					// func resetMemoryDataView()
					"runtime.resetMemoryDataView": (sp) => {
						sp >>>= 0;
						this.mem = new DataView(this._inst.exports.mem.buffer);
					},

					// func nanotime1() int64
					"runtime.nanotime1": (sp) => {
						sp >>>= 0;
						setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
					},

					// func walltime1() (sec int64, nsec int32)
					"runtime.walltime1": (sp) => {
						sp >>>= 0;
						const msec = (new Date).getTime();
						setInt64(sp + 8, msec / 1000);
						this.mem.setInt32(sp + 16, (msec % 1000) * 1000000, true);
					},

					// func scheduleTimeoutEvent(delay int64) int32
					"runtime.scheduleTimeoutEvent": (sp) => {
						sp >>>= 0;
						const id = this._nextCallbackTimeoutID;
						this._nextCallbackTimeoutID++;
						this._scheduledTimeouts.set(id, setTimeout(
							() => {
								this._resume();
								while (this._scheduledTimeouts.has(id)) {
									// for some reason Go failed to register the timeout event, log and try again
									// (temporary workaround for https://github.com/golang/go/issues/28975)
									console.warn("scheduleTimeoutEvent: missed timeout event");
									this._resume();
								}
							},
							getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early
						));
						this.mem.setInt32(sp + 16, id, true);
					},

					// func clearTimeoutEvent(id int32)
					"runtime.clearTimeoutEvent": (sp) => {
						sp >>>= 0;
						const id = this.mem.getInt32(sp + 8, true);
						clearTimeout(this._scheduledTimeouts.get(id));
						this._scheduledTimeouts.delete(id);
					},

					// func getRandomData(r []byte)
					"runtime.getRandomData": (sp) => {
						sp >>>= 0;
						crypto.getRandomValues(loadSlice(sp + 8));
					},

					// func finalizeRef(v ref)
					"syscall/js.finalizeRef": (sp) => {
						sp >>>= 0;
						const id = this.mem.getUint32(sp + 8, true);
						this._goRefCounts[id]--;
						if (this._goRefCounts[id] === 0) {
							const v = this._values[id];
							this._values[id] = null;
							this._ids.delete(v);
							this._idPool.push(id);
						}
					},

					// func stringVal(value string) ref
					"syscall/js.stringVal": (sp) => {
						sp >>>= 0;
						storeValue(sp + 24, loadString(sp + 8));
					},

					// func valueGet(v ref, p string) ref
					"syscall/js.valueGet": (sp) => {
						sp >>>= 0;
						const result = Reflect.get(loadValue(sp + 8), loadString(sp + 16));
						sp = this._inst.exports.getsp() >>> 0; // see comment above
						storeValue(sp + 32, result);
					},

					// func valueSet(v ref, p string, x ref)
					"syscall/js.valueSet": (sp) => {
						sp >>>= 0;
						Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
					},

					// func valueDelete(v ref, p string)
					"syscall/js.valueDelete": (sp) => {
						sp >>>= 0;
						Reflect.deleteProperty(loadValue(sp + 8), loadString(sp + 16));
					},

					// func valueIndex(v ref, i int) ref
					"syscall/js.valueIndex": (sp) => {
						sp >>>= 0;
						storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
					},

					// valueSetIndex(v ref, i int, x ref)
					"syscall/js.valueSetIndex": (sp) => {
						sp >>>= 0;
						Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
					},

					// func valueCall(v ref, m string, args []ref) (ref, bool)
					"syscall/js.valueCall": (sp) => {
						sp >>>= 0;
						try {
							const v = loadValue(sp + 8);
							const m = Reflect.get(v, loadString(sp + 16));
							const args = loadSliceOfValues(sp + 32);
							const result = Reflect.apply(m, v, args);
							sp = this._inst.exports.getsp() >>> 0; // see comment above
							storeValue(sp + 56, result);
							this.mem.setUint8(sp + 64, 1);
						} catch (err) {
							storeValue(sp + 56, err);
							this.mem.setUint8(sp + 64, 0);
						}
					},

					// func valueInvoke(v ref, args []ref) (ref, bool)
					"syscall/js.valueInvoke": (sp) => {
						sp >>>= 0;
						try {
							const v = loadValue(sp + 8);
							const args = loadSliceOfValues(sp + 16);
							const result = Reflect.apply(v, undefined, args);
							sp = this._inst.exports.getsp() >>> 0; // see comment above
							storeValue(sp + 40, result);
							this.mem.setUint8(sp + 48, 1);
						} catch (err) {
							storeValue(sp + 40, err);
							this.mem.setUint8(sp + 48, 0);
						}
					},

					// func valueNew(v ref, args []ref) (ref, bool)
					"syscall/js.valueNew": (sp) => {
						sp >>>= 0;
						try {
							const v = loadValue(sp + 8);
							const args = loadSliceOfValues(sp + 16);
							const result = Reflect.construct(v, args);
							sp = this._inst.exports.getsp() >>> 0; // see comment above
							storeValue(sp + 40, result);
							this.mem.setUint8(sp + 48, 1);
						} catch (err) {
							storeValue(sp + 40, err);
							this.mem.setUint8(sp + 48, 0);
						}
					},

					// func valueLength(v ref) int
					"syscall/js.valueLength": (sp) => {
						sp >>>= 0;
						setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
					},

					// valuePrepareString(v ref) (ref, int)
					"syscall/js.valuePrepareString": (sp) => {
						sp >>>= 0;
						const str = encoder.encode(String(loadValue(sp + 8)));
						storeValue(sp + 16, str);
						setInt64(sp + 24, str.length);
					},

					// valueLoadString(v ref, b []byte)
					"syscall/js.valueLoadString": (sp) => {
						sp >>>= 0;
						const str = loadValue(sp + 8);
						loadSlice(sp + 16).set(str);
					},

					// func valueInstanceOf(v ref, t ref) bool
					"syscall/js.valueInstanceOf": (sp) => {
						sp >>>= 0;
						this.mem.setUint8(sp + 24, (loadValue(sp + 8) instanceof loadValue(sp + 16)) ? 1 : 0);
					},

					// func copyBytesToGo(dst []byte, src ref) (int, bool)
					"syscall/js.copyBytesToGo": (sp) => {
						sp >>>= 0;
						const dst = loadSlice(sp + 8);
						const src = loadValue(sp + 32);
						if (!(src instanceof Uint8Array || src instanceof Uint8ClampedArray)) {
							this.mem.setUint8(sp + 48, 0);
							return;
						}
						const toCopy = src.subarray(0, dst.length);
						dst.set(toCopy);
						setInt64(sp + 40, toCopy.length);
						this.mem.setUint8(sp + 48, 1);
					},

					// func copyBytesToJS(dst ref, src []byte) (int, bool)
					"syscall/js.copyBytesToJS": (sp) => {
						sp >>>= 0;
						const dst = loadValue(sp + 8);
						const src = loadSlice(sp + 16);
						if (!(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)) {
							this.mem.setUint8(sp + 48, 0);
							return;
						}
						const toCopy = src.subarray(0, dst.length);
						dst.set(toCopy);
						setInt64(sp + 40, toCopy.length);
						this.mem.setUint8(sp + 48, 1);
					},

					"debug": (value) => {
						console.log(value);
					},
				}
			};
		}

		async run(instance) {
			if (!(instance instanceof WebAssembly.Instance)) {
				throw new Error("Go.run: WebAssembly.Instance expected");
			}
			this._inst = instance;
			this.mem = new DataView(this._inst.exports.mem.buffer);
			this._values = [ // JS values that Go currently has references to, indexed by reference id
				NaN,
				0,
				null,
				true,
				false,
				global,
				this,
			];
			this._goRefCounts = new Array(this._values.length).fill(Infinity); // number of references that Go has to a JS value, indexed by reference id
			this._ids = new Map([ // mapping from JS values to reference ids
				[0, 1],
				[null, 2],
				[true, 3],
				[false, 4],
				[global, 5],
				[this, 6],
			]);
			this._idPool = []; // unused ids that have been garbage collected
			this.exited = false; // whether the Go program has exited

			// Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
			let offset = 4096;

			const strPtr = (str) => {
				const ptr = offset;
				const bytes = encoder.encode(str + "\0");
				new Uint8Array(this.mem.buffer, offset, bytes.length).set(bytes);
				offset += bytes.length;
				if (offset % 8 !== 0) {
					offset += 8 - (offset % 8);
				}
				return ptr;
			};

			const argc = this.argv.length;

			const argvPtrs = [];
			this.argv.forEach((arg) => {
				argvPtrs.push(strPtr(arg));
			});
			argvPtrs.push(0);

			const keys = Object.keys(this.env).sort();
			keys.forEach((key) => {
				argvPtrs.push(strPtr(`${key}=${this.env[key]}`));
			});
			argvPtrs.push(0);

			const argv = offset;
			argvPtrs.forEach((ptr) => {
				this.mem.setUint32(offset, ptr, true);
				this.mem.setUint32(offset + 4, 0, true);
				offset += 8;
			});

			this._inst.exports.run(argc, argv);
			if (this.exited) {
				this._resolveExitPromise();
			}
			await this._exitPromise;
		}

		_resume() {
			if (this.exited) {
				throw new Error("Go program has already exited");
			}
			this._inst.exports.resume();
			if (this.exited) {
				this._resolveExitPromise();
			}
		}

		_makeFuncWrapper(id) {
			const go = this;
			return function () {
				const event = {
					id: id,
					this: this,
					args: arguments
				};
				go._pendingEvent = event;
				go._resume();
				return event.result;
			};
		}
	}

	if (
		typeof module !== "undefined" &&
		global.require &&
		global.require.main === module &&
		global.process &&
		global.process.versions &&
		!global.process.versions.electron
	) {
		if (process.argv.length < 3) {
			console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
			process.exit(1);
		}

		const go = new Go();
		go.argv = process.argv.slice(2);
		go.env = Object.assign({
			TMPDIR: require("os").tmpdir()
		}, process.env);
		go.exit = process.exit;
		WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
			process.on("exit", (code) => { // Node.js exits if no event handler is pending
				if (code === 0 && !go.exited) {
					// deadlock, make Go print error and stack traces
					go._pendingEvent = {
						id: 0
					};
					go._resume();
				}
			});
			return go.run(result.instance);
		}).catch((err) => {
			console.error(err);
			process.exit(1);
		});
	}
})();