import * as child_process from 'child_process';
import * as fs from 'fs-extra';
import * as os from 'os';
import * as path from 'path';
import * as log from './log';
import {sys} from './exec';

function getWidthAndHeight(kha: string, exe: string, from: string, to: string, options: any, format: string, prealpha: boolean): Promise<{w: number, h: number}> {
	return new Promise((resolve, reject) => {
		let params = ['from=' + from, 'to=' + to, 'format=' + format, 'donothing'];
		if (options.scale !== undefined && options.scale !== 1) {
			params.push('scale=' + options.scale);
		}
		let process = child_process.spawn(exe, params);

		let output = '';
		process.stdout.on('data', (data: any) => {
			output += data.toString();
		});

		process.stderr.on('data', (data: any) => {

		});

		process.on('close', (code: number) => {
			if (code !== 0) {
				log.error('kraffiti process exited with code ' + code + ' when trying to get size of ' + path.parse(from).name);
				resolve({w: 0, h: 0});
				return;
			}
			const lines = output.split('\n');
			for (let line of lines) {
				if (line.startsWith('#')) {
					let numbers = line.substring(1).split('x');
					resolve({w: parseInt(numbers[0]), h: parseInt(numbers[1])});
					return;
				}
			}
			resolve({w: 0, h: 0});
		});
	});
}

function convertImage(from: string, temp: string, to: string, kha: string, exe: string, params: string[], options: any, cache: any): Promise<void> {
	return new Promise<void>((resolve, reject) => {
		let process = child_process.spawn(exe, params);

		let output = '';
		process.stdout.on('data', (data: any) => {
			output += data.toString();
		});

		process.stderr.on('data', (data: any) => {

		});

		process.on('close', (code: number) => {
			if (code !== 0) {
				log.error('kraffiti process exited with code ' + code + ' when trying to convert ' + path.parse(from).name);
				resolve();
				return;
			}

			fs.renameSync(temp, to);

			const lines = output.split('\n');
			for (let line of lines) {
				if (line.startsWith('#')) {
					let numbers = line.substring(1).split('x');
					cache[to] = {};
					cache[to].original_width = options.original_width = parseInt(numbers[0]);
					cache[to].original_height = options.original_height = parseInt(numbers[1]);
					resolve();
					return;
				}
			}
			resolve();
		});
	});
}

export async function exportImage(kha: string, exe: string, from: string, to: string, options: any, format: string, prealpha: boolean, poweroftwo: boolean, cache: any): Promise<string> {
	if (format === undefined) {
		if (from.toString().endsWith('.png')) format = 'png';
		else if (from.toString().endsWith('.hdr')) format = 'hdr';
		else format = 'jpg';
	}

	if (format === 'jpg' && (options.scale === undefined || options.scale === 1) && options.background === undefined) {
		to = to + '.jpg';
	}
	else if (format === 'pvr') {
		to = to + '.pvr';
	}
	else if (format === 'ASTC') {
		to = to + '.astc.k';
	}
	else if (format === 'DXT5') {
		to = to + '.dxt5.k';
	}
	else if (format === 'hdr') {
		to = to + '.hdr';
	}
	else if (format === 'lz4') {
		to += '.k';
	}
	else {
		format = 'png';
		if (prealpha) to = to + '.kng';
		else to = to + '.png';
	}

	let temp = to + '.temp';

	let outputformat = format;
	if (format === 'png' && prealpha) {
		outputformat = 'kng';
	}
	if (format === 'lz4') {
		outputformat = 'k';
	}
	if (format === 'ASTC') {
		outputformat = 'astc.k';
	}
	if (format === 'DXT5') {
		outputformat = 'dxt5.k';
	}

	if (fs.existsSync(to) && fs.statSync(to).mtime.getTime() > fs.statSync(from.toString()).mtime.getTime()) {
		if (cache[to] !== undefined) {
			const cachedOptions = cache[to];
			options.original_width = cachedOptions.original_width;
			options.original_height = cachedOptions.original_height;
			return outputformat;
		}
		let wh = await getWidthAndHeight(kha, exe, from, to, options, format, prealpha);
		cache[to] = {};
		cache[to].original_width = options.original_width = wh.w;
		cache[to].original_height = options.original_height = wh.h;
		return outputformat;
	}

	fs.ensureDirSync(path.dirname(to));

	if (format === 'jpg' || format === 'hdr') {
		fs.copySync(from, temp, { overwrite: true });
		fs.renameSync(temp, to);
		let wh = await getWidthAndHeight(kha, exe, from, to, options, format, prealpha);
		options.original_width = wh.w;
		options.original_height = wh.h;
		return outputformat;
	}

	let params = ['from=' + from, 'to=' + temp, 'format=' + format];
	if (!poweroftwo) {
		params.push('filter=nearest');
	}
	if (prealpha) params.push('prealpha');
	if (options.scale !== undefined && options.scale !== 1) {
		params.push('scale=' + options.scale);
	}
	if (options.background !== undefined) {
		params.push('transparent=' + ((options.background.red << 24) | (options.background.green << 16) | (options.background.blue << 8) | 0xff).toString(16));
	}
	if (poweroftwo) {
		params.push('poweroftwo');
	}

	await convertImage(from, temp, to, kha, exe, params, options, cache);
	return outputformat;
}