/*
 * Copyright (C)2005-2019 Haxe Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

package sys.db;

import haxe.crypto.BaseCode;

private typedef SqliteConnectionHandle = hl.Abstract<"sqlite_database">;
private typedef SqliteResultHandle = hl.Abstract<"sqlite_result">;

@:hlNative("sqlite")
private class SqliteLib {
	public static function connect(path:hl.Bytes):SqliteConnectionHandle {
		return null;
	}

	public static function close(c:SqliteConnectionHandle):Void {}

	public static function request(c:SqliteConnectionHandle, sql:hl.Bytes):SqliteResultHandle {
		return null;
	}

	public static function last_id(c:SqliteConnectionHandle):Int {
		return 0;
	}

	public static function result_next(c:SqliteResultHandle):hl.NativeArray<Dynamic> {
		return null;
	}

	public static function result_get(c:SqliteResultHandle, n:Int):Null<hl.Bytes> {
		return null;
	}

	public static function result_get_int(c:SqliteResultHandle, n:Int):Null<Int> {
		return 0;
	}

	public static function result_get_float(c:SqliteResultHandle, n:Int):Null<Float> {
		return .0;
	}

	public static function result_get_length(c:SqliteResultHandle):Null<Int> {
		return 0;
	}

	public static function result_get_nfields(c:SqliteResultHandle):Int {
		return 0;
	}

	public static function result_get_fields(c:SqliteResultHandle):hl.NativeArray<hl.Bytes> {
		return null;
	}
}

@:access(Sys)
@:access(String)
private class SqliteConnection implements Connection {
	var c:SqliteConnectionHandle;

	public function new(file:String) {
		c = SqliteLib.connect(file.bytes);
	}

	public function close():Void {
		SqliteLib.close(c);
	}

	public function request(s:String):ResultSet {
		try {
			var r:SqliteResultHandle = SqliteLib.request(c, s.bytes);

			return new SqliteResultSet(r);
		} catch (e:String) {
			throw 'Error while executing $s ($e)';
		}

		return null;
	}

	public function escape(s:String):String {
		return s.split("'").join("''");
	}

	public function quote(s:String):String {
		if (s.indexOf("\000") >= 0)
			return "x'" + BaseCode.encode(s, "0123456789ABCDEF") + "'";

		return "'" + s.split("'").join("''") + "'";
	}

	public function addValue(s:StringBuf, v:Dynamic):Void {
		switch (Type.typeof(v)) {
			case TNull, TInt:
				s.add(v);
			case TBool:
				s.add(v ? 1 : 0);
			case TClass(haxe.io.Bytes):
				s.add("x'");
				s.add((v : haxe.io.Bytes).toHex());
				s.add("'");
			case _:
				s.add(quote(Std.string(v)));
		}
	}

	public function lastInsertId():Int {
		return SqliteLib.last_id(c);
	}

	public function dbName():String {
		return "SQLite";
	}

	public function startTransaction():Void {
		request("BEGIN TRANSACTION");
	}

	public function commit():Void {
		request("COMMIT");
		startTransaction(); // match mysql usage
	}

	public function rollback():Void {
		request("ROLLBACK");
		startTransaction(); // match mysql usage
	}
}

@:access(String)
private class SqliteResultSet implements ResultSet {
	public var length(get, null):Int;
	public var nfields(get, null):Int;

	var names:Array<String>;
	var cache:List<Dynamic>;

	var r:SqliteResultHandle;

	public function new(r:SqliteResultHandle) {
		cache = new List();
		this.r = r;
		hasNext(); // execute the request
	}

	function get_length():Int {
		if (nfields != 0) {
			while (true) {
				var c = doNext();
				if (c == null)
					break;

				cache.add(c);
			}

			return cache.length;
		}

		return SqliteLib.result_get_length(r);
	}

	function get_nfields():Int {
		return SqliteLib.result_get_nfields(r);
	}

	public function hasNext():Bool {
		var c = next();
		if (c == null)
			return false;

		cache.push(c);

		return true;
	}

	public function next():Dynamic {
		var c = cache.pop();
		if (c != null)
			return c;

		return doNext();
	}

	private function doNext():Dynamic {
		var o:Dynamic = {};
		var a = SqliteLib.result_next(r);
		if (a == null)
			return null;

		var names = getFieldsNames();
		var i = 0;
		var l = names.length;
		while (i < l) {
			var n:String = names[i];
			var v:Dynamic = a[i];
			switch (hl.Type.getDynamic(v).kind) {
				case hl.Type.TypeKind.HArray:
					var pair:hl.NativeArray<Dynamic> = v;
					var bytes:hl.Bytes = pair[0];
					var len:Int = pair[1];
					var data = new haxe.io.BytesData(bytes, len);
					Reflect.setField(o, n, haxe.io.Bytes.ofData(data));

				case hl.Type.TypeKind.HBytes:
					Reflect.setField(o, n, String.fromUCS2(v));

				default:
					Reflect.setField(o, n, v);
			}
			i++;
		}
		return o;
	}

	public function results():List<Dynamic> {
		var l = new List();
		while (true) {
			var c = next();
			if (c == null)
				break;

			l.add(c);
		}

		return l;
	}

	public function getResult(n:Int):String {
		var bytes = SqliteLib.result_get(r, n);
		if (bytes == null)
			return null;

		return String.fromUCS2(bytes);
	}

	public function getIntResult(n:Int):Int {
		return SqliteLib.result_get_int(r, n);
	}

	public function getFloatResult(n:Int):Float {
		return SqliteLib.result_get_float(r, n);
	}

	public function getFieldsNames():Array<String> {
		if (this.names != null)
			return this.names;

		this.names = [];
		var names = SqliteLib.result_get_fields(r);
		var i = 0;
		var l = names.length;
		while (i < l) {
			var name = String.fromUCS2(names[i]);
			this.names.push(name);
			i++;
		}

		return this.names;
	}
}

@:coreApi class Sqlite {
	public static function open(file:String):Connection {
		return new SqliteConnection(file);
	}
}