//todo: Make this a module/mjs file. C6 compatibility can stay, if needed.
//LOOKING FOR: LZARI implementation (for MAX), description of CBS compression (node zlib doesn't tackle it, even with RC4'ing the data)
ICONJS_DEBUG = false;
ICONJS_STRICT = true;
ICONJS_VERSION = "0.5.0";

function setDebug(value) {
	ICONJS_DEBUG = !!value;
}

function setStrictness(value) {
	ICONJS_STRICT = !!value;
}

// where U = uncompressed, N = none, C = compressed

function getTextureFormat(i) {
	if (i<8) {
		if(i==3) {
			return 'N';
		}
		return 'U';
	} else if (i>=8) {
		return 'C';
	} else {
		return void(0);
	}
}

function uncompressTexture(texData) {
	// for texture formats 8-15
	if (texData.length & 1) {
		throw "Texture size isn't a multiple of 2 (was ${texData.length})";
	}
	const view = new DataView(texData);
	const u16le = function(i){return view.getUint16(i, 1)}
	let uncompressed = new Uint16Array(16384);
	let offset = 0;
	for (let index = 0; index < 16384;) {
		currentValue = u16le(offset);
		if(currentValue === 0) {
			// if this is specifically a katamari 1 or 2 icon, skip this byte
			// because it's formatted like that for some reason
			offset += 2;
			currentValue = u16le(offset);
		}
		offset += 2;
		if (currentValue >= 0xff00) {
			//do a raw copy of the next currentValue bytes
			let length = ((0x10000 - currentValue));
			for (let enumerator = 0; enumerator < length; enumerator++) {
				uncompressed[index] = u16le(offset);
				offset += 2;
				index++;
			}
		} else {
			//repeat next byte currentValue times
			uncompressed[index] = u16le(offset);
			for (let indey = 0; indey < currentValue; indey++) {
				uncompressed[index] = u16le(offset);
				index++
			}
			offset += 2;
		}
	}
	return uncompressed;
}

function convertBGR5A1toRGB5A1(bgrData) {
	if(bgrData.byteLength !== 32768) {
		throw `Not a 128x128x16 texture. (length was ${bgrData.length})`;
	}
	// converts 5-bit blue, green, red (in that order) with one alpha bit to GL-compatible RGB5A1
	let converted = new Uint16Array(16384);
	for (let index = 0; index < 16384; index++) {
		let b = ( bgrData[index]         & 0b11111);
		let g = ((bgrData[index] >>  5) & 0b11111);
		let r = ((bgrData[index] >> 10) & 0b11111);
		//               rrrrrgggggbbbbba (a = 1 because 0 is 127 which is 1.0f opacity for the GS)
		let newValue = 0b0000000000000001;
		// mind you, the alpha bit      ^ seems to be set randomly on textures, anyway. Maybe i'm reading these wrong?
		newValue |= (r << 1);
		newValue |= (g << 6);
		newValue |= (b << 11);
		converted[index] = newValue;
	}
	return converted;
}

function stringScrubber(dirty) {
	return dirty.replaceAll("\x00","").substring(0, (dirty.indexOf("\x00") === -1) ? dirty.length : dirty.indexOf("\x00"));
}

function readPS2D(input) {
	const view = new DataView(input);
	const u32le = function(i){return view.getUint32(i, 1)}
	const f32le = function(i){return view.getFloat32(i, 1)}
	//!pattern ps2d.hexpat
	const header = u32le(0);
	if (header !== 0x44325350) {
		throw `Not a PS2D file (was ${header}, expected ${0x44325350})`;
	}
	//:skip 2
	const titleOffset = u32le(6);
	//:skip 2
	const bgAlpha = u32le(12); // should read as a u8, (k/127?.5) for float value (255 = a(2.0~))
	const bgColors = [
		{r: u32le(16), g: u32le(20), b: u32le(24), a: u32le(28)},
		{r: u32le(32), g: u32le(36), b: u32le(40), a: u32le(44)},
		{r: u32le(48), g: u32le(52), b: u32le(56), a: u32le(60)},
		{r: u32le(64), g: u32le(68), b: u32le(72), a: u32le(76)}
	]; // top-left, top-right, bottom-left, bottom-right;
	const lightIndices = [
		{x: f32le(80), y: f32le(84), z: f32le(88)}, //:skip 4
		{x: f32le(96), y: f32le(100), z: f32le(104)}, //:skip 4
		{x: f32le(112), y: f32le(116), z: f32le(120)} //:skip 4
	]
	const lightColors = [
		{r: f32le(128), g: f32le(132), b: f32le(136), a: f32le(140)},
		{r: f32le(144), g: f32le(148), b: f32le(152), a: f32le(156)},
		{r: f32le(160), g: f32le(164), b: f32le(168), a: f32le(172)},
		{r: f32le(176), g: f32le(180), b: f32le(184), a: f32le(188)}	
	]
	// P2SB says color 1 is ambient, 2-4 are for 3-point cameras
	// official HDD icon.sys files (completely different PS2ICON text-based format) also say the same.
	const int_title = input.slice(0xc0, 0x100);
	const tmp_title16 = new Uint16Array(int_title);
	for (let index = 0; index < 32; index++) {
		//find "bad" shift-jis two-bytes, and convert to spaces (or NULL if strict)
		if(tmp_title16[index] === 129 || tmp_title16[index] === 33343) {
			console.warn(`PS2D syntax error: known bad two-byte sequence 0x${tmp_title16[index].toString(16).padEnd(4,"0")} (at ${index}). Replacing with ${(ICONJS_STRICT) ? "NULL" : "0x8140"}.\n${(ICONJS_STRICT) ? "This is console-accurate, so" : "An actual console does not do this."} I recommend patching your icon.sys files!`);
			tmp_title16[index] = (ICONJS_STRICT) ? 0 : 0x4081; // is a reference, so this'll edit int_title too
		}
	}
	//:skip 4 -- Unless proven, keep 64 bytes for display name.
	const int_filename_n = input.slice(0x104, 0x143);
	const int_filename_c = input.slice(0x144, 0x183);
	const int_filename_d = input.slice(0x184, 0x1C3);
	//;skip 512 -- rest of this is just padding
	const rawTitle = (new TextDecoder("shift-jis")).decode(int_title);
	const title = [
		stringScrubber(rawTitle.substring(0,(titleOffset/2))), 
		(rawTitle.indexOf("\x00") < (titleOffset/2)) ? "" : stringScrubber(rawTitle.substring((titleOffset/2)))
	];
	const filenames = {
		n: stringScrubber((new TextDecoder("utf-8")).decode(int_filename_n)),
		c: stringScrubber((new TextDecoder("utf-8")).decode(int_filename_c)),
		d: stringScrubber((new TextDecoder("utf-8")).decode(int_filename_d))
	}
	if(ICONJS_DEBUG){
		console.log({header, titleOffset, bgAlpha, bgColors, lightIndices, lightColors, title, filenames});
	}
	return {filenames, title, background: {colors: bgColors, alpha: bgAlpha}, lighting: {points: lightIndices, colors: lightColors}};
}

function readIconFile(input) {
	//!pattern ps2icon-hacked.hexpat
	const view = new DataView(input);
	const u32le = function(i){return view.getUint32(i, 1)}
	const f32le = function(i){return view.getFloat32(i, 1)}
	const f16le = function(i){return (view.getInt16(i, 1) / 4096)}
	const u32_rgba8 =	function(i) {return {
		r: (i & 0xff), 
		g: ((i & 0xff00) >> 8), 
		b: ((i & 0xff0000) >> 16), 
		a: (i > 0x7fffffff ? 255 : (((i & 0xff000000) >>> 24) * 2)+1)
		// I don't think alpha transparency is actually USED in icons?, rendering with it looks strange.
	}};
	const magic = u32le(0);
	if (magic !== 0x010000) {
		// USER NOTICE: So far, I have yet to parse an icon that hasn't had 0x00010000 as it's magic.
		//              Can someone provide me pointers to such an icon if one exists?
		throw `Not a PS2 icon file (was ${magic}, expected ${0x010000})`;
	}
	const numberOfShapes = u32le(4);
	if(numberOfShapes > 16) {
		throw `Too many defined shapes! Is this a valid file? (file reports ${numberOfShapes} shapes)`;
	}
	const textureType = u32le(8);
	const textureFormat = getTextureFormat(textureType);
	//:skip 4
	const numberOfVertexes = u32le(16);
	if(!!(numberOfVertexes % 3)){
		throw `Not enough vertices to define a triangle (${numberOfVertexes % 3} vertices remained).`;
	}
	// format: [xxyyzzaa * numberOfShapes][xxyyzzaa][uuvvrgba], ((8 * numberOfShapes) + 16) [per chunk]
	let offset = 20;
	let vertices = new Array();
	const chunkLength = ((numberOfShapes * 8) + 16);

	// for numberOfVertexes, copy chunkLength x times, then append with normal, uv and rgba8 color. Floats are 16-bit.
	for (let index = 0; index < numberOfVertexes; index++) {
		let shapes = new Array();
		for (let indey = 0; indey < numberOfShapes; indey++) {
			shapes.push({
				x: f16le(offset+((chunkLength*index)+(indey*8))), 
				y: f16le(offset+((chunkLength*index)+(indey*8))+2), 
				z: f16le(offset+((chunkLength*index)+(indey*8))+4)
			});
			//:skip 2
		}
		
		let normal = {
			x: f16le(offset+(chunkLength*index)+((numberOfShapes * 8))), 
			y: f16le(offset+(chunkLength*index)+((numberOfShapes * 8))+2), 
			z: f16le(offset+(chunkLength*index)+((numberOfShapes * 8))+4)
		};
		//:skip 2
		let uv = {
			u: f16le(offset+(chunkLength*index)+((numberOfShapes * 8))+8), 
			v: f16le(offset+(chunkLength*index)+((numberOfShapes * 8))+10)
		};
		let color = u32_rgba8(u32le(offset+(chunkLength*index)+((numberOfShapes * 8))+12));
		// keep original u32le color?
		vertices.push({shapes, normal, uv, color});
	}
	offset = (20+(numberOfVertexes * chunkLength));
	animationHeader = {id: u32le(offset), length: u32le(offset+4), speed: f32le(offset+8), "offset": u32le(offset+12), keyframes: u32le(offset+16)};
	let animData = new Array();
	// now we have to enumerate values, so now we introduce an offset value.
	// format for a keyframe: sssskkkk[ffffvvvv] where [ffffvvvv] repeat based on the value that kkkk(eys) has.
	// sssskkkk[ffffvvvv] is repeated based on animationHeader.keyframes value.
	offset += 20;
	for (let index = 0; index < animationHeader.keyframes; index++) {
		let frameData = new Array();
		let shapeId = u32le(offset);
		let keys = u32le(offset+4);
		offset += 8;
		for (let indey = 0; indey < keys; indey++) {
			frameData.push({frame: f32le(offset), value: f32le(offset+4)});
			offset += 8;
		}
		animData.push({shapeId, keys, frameData});
	}
	let texture = null;
	switch(textureFormat) {
		case 'N': {
			break;
		}
		case 'U': {
			//where every 16-bit entry is a BGR5A1 color 0b[bbbbbgggggrrrrra]
			texture = new Uint16Array(input.slice(offset, (offset+0x8000)));
			//see convertBGR5A1toRGB5A1() for more info.
			break;
		}
		case 'C': {
			// compression format is RLE-based, where first u32 is size, and format is defined as:
			/**
			* u16 rleType;
			* if (rleType >= 0xff00) {
			*	//do a raw copy
			*	let length = (0x10000 - rleType);
			*	byte data[length];
			* } else {
			*	//repeat next byte rleType times
			*	data = new Uint16Array(rleType);
			*	for (let index = 0; index < rleType; index++) {
			*		data[index] = u16 repeater @ +4;
			*	}
			* }
			**/
			//output of this will be another u16[0x4000] of the decompressed texture
			//after that just parse output as-if it was uncompressed.
			//see uncompressTexture() and convertBGR5A1toRGB5A1() for more info.
			size = u32le(offset);
			texture = {size, data: input.slice(offset+4, offset+(4+size))};
		}
	}
	if(ICONJS_DEBUG){
		console.log({magic, numberOfShapes, textureType, textureFormat, numberOfVertexes, chunkLength, vertices, animationHeader, animData, texture});
	}
	return {numberOfShapes, vertices, textureFormat, texture, animData};
}

function readEntryBlock(input) {
	const view = new DataView(input);
	const u32le = function(i){return view.getUint32(i, 1)};
	const t64le = function(i){return {
		seconds: view.getUint8(i+1),
		minutes: view.getUint8(i+2),
		hours: view.getUint8(i+3),
		day: view.getUint8(i+4),
		month: view.getUint8(i+5),
		year: view.getUint16(i+6, 1)
	}}; //NOTE: times are in JST timezone (GMT+09:00), so clients should implement correctly!
	//!pattern psu_file.hexpat
	const permissions = u32le(0);
	let type;
	if (permissions>0xffff) {
		throw `Not a EMS Memory Adapter (PSU) export file (was ${permissions}, expected less than ${0xffff})`;
	}
	if((permissions & 0b00100000)>=1){
		type = "directory";
	}
	if((permissions & 0b00010000)>=1){
		type = "file";
	}
	if((permissions & 0b0001100000000000)>=1){
		throw `I don't parse portable applications or legacy save data. (${permissions} has bits 10 or 11 set)`;
	}
	const size = u32le(4);
	const createdTime = t64le(8);
	const sectorOffset = u32le(16);
	const dirEntry = u32le(20);
	const modifiedTime = t64le(24);
	const specialSection = input.slice(0x20, 0x40);
	const int_filename = input.slice(0x40, 512); 
	const filename = stringScrubber((new TextDecoder("utf-8")).decode(int_filename));
	if(ICONJS_DEBUG){
		console.log({permissions, type, size, createdTime, sectorOffset, dirEntry, modifiedTime, specialSection, filename});
	}
	return {type, size, filename, createdTime, modifiedTime};
}

function readEmsPsuFile(input){
	const header = readEntryBlock(input.slice(0,0x1ff));
	if(header.size > 0x7f) {
		throw `Directory is too large! (maximum size: ${0x7f}, was ${header.size})`
	}
	let fsOut = {length: header.size, rootDirectory: header.filename, timestamps: {created: header.createdTime, modified: header.modifiedTime}};
	let output = new Object();
	let offset = 512;
	for (let index = 0; index < header.size; index++) {
		fdesc = readEntryBlock(input.slice(offset, offset + 512));
		switch(fdesc.type) {
			case "directory": {
				offset += 512;
				output[fdesc.filename] = null;
				break;
			}
			case "file": {
				if(ICONJS_DEBUG){
					console.log(`PARSING | F: "${fdesc.filename}" O: ${offset} S: ${fdesc.size}`);
				}
				offset += 512;
				const originalOffset = offset;
				if((fdesc.size % 1024) > 0) {
					offset += ((fdesc.size & 0b11111111110000000000) + 1024);
				} else {
					offset += fdesc.size;
					// if we're already filling 1k blocks fully, why change the value?
				}
				output[fdesc.filename] = {
					size: fdesc.size,
					data: input.slice(originalOffset, originalOffset+fdesc.size)
				};
				break;
			}
		}
	}
	fsOut[header.filename] = output;
	return fsOut;
}

function readPsvFile(input){
	const view = new DataView(input);
	const u32le = function(i){return view.getUint32(i, 1)};
	const t64le = function(i){return {
		seconds: view.getUint8(i+1),
		minutes: view.getUint8(i+2),
		hours: view.getUint8(i+3),
		day: view.getUint8(i+4),
		month: view.getUint8(i+5),
		year: view.getUint16(i+6, 1)
	}};
	//!pattern psv_file.hexpat
	const magic = u32le(0);
	if (magic !== 0x50535600) {
		throw `Not a PS3 export (PSV) file (was ${magic}, expected ${0x50535600})`;
	}
	//:skip 4
	//:skip 20 // key seed, console ignores this 
	//:skip 20 // sha1 hmac digest, useful for verifying that this is, indeed, save data.
	//:skip 8
	const type1 = u32le(56);
	const type2 = u32le(60);
	if(type1 !== 0x2c && type2 !== 2) {
		throw `Not parsing, this is not in the PS2 save export format (was ${type1}:${type2}, expected 44:2)`;
	}
	const displayedSize = u32le(64);
	const ps2dOffset = u32le(68);
	const ps2dSize = u32le(72); // don't know why this is included if its always 964
	const nModelOffset = u32le(76);
	const nModelSize = u32le(80);
	const cModelOffset = u32le(84);
	const cModelSize = u32le(88);
	const dModelOffset = u32le(92);
	const dModelSize = u32le(96);
	const numberOfFiles = u32le(100); // in-case this library changes stance on other files
	// file = {t64le created, t64le modified, u32 size, u32 permissions, byte[32] title}
	// and if it's not the root directory, add another u32 for offset/location
	const rootDirectoryData = input.slice(104, 162);
	const timestamps = {created: t64le(104), modified: t64le(112)};
	let offset = 162;
	let fileData = new Array();
	for (let index = 0; index < numberOfFiles; index++) {
		fileData.push(input.slice(offset,offset+0x3c));
		offset += 0x3c;
	};
	//then file data after this but we already have pointers to the files we care about
	const icons = {
		n: input.slice(nModelOffset, nModelOffset+nModelSize),
		c: input.slice(cModelOffset, cModelOffset+cModelSize),
		d: input.slice(dModelOffset, dModelOffset+dModelSize),
	}
	if (ICONJS_DEBUG) {
		console.log({magic, type1, type2, displayedSize, ps2dOffset, ps2dSize, nModelOffset, nModelSize, cModelOffset, cModelSize, dModelOffset, dModelSize, numberOfFiles, rootDirectoryData, fileData})
	}
	return {icons, "icon.sys": input.slice(ps2dOffset, ps2dOffset+ps2dSize), timestamps};
}

function readSxpsDescriptor(input) {
	const view = new DataView(input);
	const u32le = function(i){return view.getUint32(i, 1)};
	const t64le = function(i){return {
		seconds: view.getUint8(i+1),
		minutes: view.getUint8(i+2),
		hours: view.getUint8(i+3),
		day: view.getUint8(i+4),
		month: view.getUint8(i+5),
		year: view.getUint16(i+6, 1)
	}}; //NOTE: times are in JST timezone (GMT+09:00), so clients should implement correctly!
	//!pattern sps-xps_file.hexpat
	//:skip 2 // ... it's the file descriptor block size (including the bytes themselves, so 250)
	const int_filename = input.slice(2, 66);
	const filename = stringScrubber((new TextDecoder("utf-8")).decode(int_filename));
	const size = u32le(66);
	const startSector = u32le(70);
	const endSector = u32le(74);
	const permissions = u32le(78); // the first two bytes are *swapped*. The comments that ensued were not kept.
	let type;
	if (permissions>0xffff) {
		throw `Not a SharkPort (SPS) or X-Port (XPS) export file (was ${permissions}, expected less than ${0xffff})`;
	}
	if((permissions & 0b0010000000000000)>=1){
		type = "directory";
	}
	if((permissions & 0b0001000000000000)>=1){
		type = "file";
	}
	if((permissions & 0b00011000)>=1){
		throw `I don't parse portable applications or legacy save data. (${permissions} has bits 4 or 5 set)`;
	}
	const timestamps = {created: t64le(82), modified: t64le(90)};
	//:skip 4
	//:skip 4 - u32 optional (98)
	//:skip 8 - t64 optionalTime (102) // I don't know why this is here.
	const int_asciiName = input.slice(114, 178);
	const int_shiftjisName = input.slice(178, 242); // Because why parse a PS2D when you can hard-code it?
	//:skip 8
	if(ICONJS_DEBUG) {
		console.log({int_filename, size, startSector, endSector, permissions, type, timestamps, int_asciiName, int_shiftjisName});
	}
	return {type, size, filename, timestamps};
}

function readSharkXPortSxpsFile(input) {
	const view = new DataView(input);
	const u32le = function(i){return view.getUint32(i, 1)};
	//!pattern sps-xps_file.hexpat
	const identLength = u32le(0);
	if(identLength !== 13) {
		throw `Not a SharkPort (SPS) or X-Port (XPS) export file (was ${identLength}, expected 13)`;
	}
	let offset = 4;
	const ident = input.slice(offset, offset+identLength);
	if((new TextDecoder("utf-8")).decode(ident) !== "SharkPortSave") {
		throw `Unrecognized file identification string. Expected "SharkPortSave".`
	}
	offset += (identLength + 4);
	const titleLength = u32le(offset);
	const title = input.slice(offset + 4, (offset + 4) + titleLength);
	offset += (titleLength + 4);
	const descriptionLength = u32le(offset);
	const description = input.slice(offset + 4, (offset + 4) + descriptionLength);
	offset += (descriptionLength + 8);
	const comments = {
		"game": stringScrubber((new TextDecoder("utf-8")).decode(title)),
		"name": stringScrubber((new TextDecoder("utf-8")).decode(description))
	}
	const totalSize = u32le(offset);
	offset += 4;
	const header = readSxpsDescriptor(input.slice(offset, offset + 250));
	offset += 250;
	// alright now lets parse some actual data
	let fsOut = {length: header.size, rootDirectory: header.filename, timestamps: header.timestamps, comments};
	let output = new Object();
	for (let index = 0; index < (header.size - 2); index++) {
		fdesc = readSxpsDescriptor(input.slice(offset, offset + 250));
		switch(fdesc.type) {
			case "directory": {
				offset += 250;
				output[fdesc.filename] = null;
				break;
			}
			case "file": {
				if(ICONJS_DEBUG){
					console.log(`PARSING | F: "${fdesc.filename}" O: ${offset} S: ${fdesc.size}`);
				}
				offset += 250;
				output[fdesc.filename] = {
					size: fdesc.size,
					data: input.slice(offset, offset+fdesc.size)
				};
				offset += fdesc.size;
				break;
			}
		}
	}
	fsOut[header.filename] = output;
	//:skip 4 //  then here lies, at offset (the end of file), a u32 checksum.
	return fsOut;
}

if(typeof module !== "undefined") {
	// for C6JS
	module.exports = {
		readers: {readIconFile, readPS2D, readEmsPsuFile, readPsvFile, readSharkXPortSxpsFile},
		helpers: {uncompressTexture, convertBGR5A1toRGB5A1}, 
		options: {setDebug, setStrictness},
		version: ICONJS_VERSION
	};
}