/**
 * Classes implementing antlr4 streams and providing an interface to interact with the compiler. Extends basic
 * stream functionality from the core kipper module.
 * @since 0.0.3
 */
import { constants, promises as fs } from "fs";
import * as path from "path";
import { KipperFileStream } from "@kipper/core";
import { KipperFileAccessError, KipperInvalidInputError, KipperUnsupportedEncodingError } from "../errors";
import type { OutputArgs, OutputFlags } from "@oclif/parser/lib/parse";
import type { EvaluatedKipperConfigFile } from "@kipper/config";

/**
 * Valid encodings that Kipper supports.
 * @since 0.1.0
 */
export type KipperEncoding = "ascii" | "utf-8" | "utf8" | "utf16le";

/**
 * Array of all valid encodings that Kipper supports.
 * @since 0.1.0
 */
export const KipperEncodings: Array<KipperEncoding> = ["ascii", "utf-8", "utf8", "utf16le"];

/**
 * Checks whether the encoding is supported. If it is, then it will return it as {@link KipperEncoding}, otherwise it
 * will throw {@link KipperUnsupportedEncodingError}.
 * @param encoding
 * @throws KipperUnsupportedEncodingError If the encoding is not supported by Kipper.
 */
export function verifyEncoding(encoding: string): KipperEncoding {
	const kipperEncoding = KipperEncodings.find((i) => i == encoding);
	if (kipperEncoding) {
		return kipperEncoding;
	} else {
		throw new KipperUnsupportedEncodingError(encoding);
	}
}

function ensureCompatibleFiles(files: Array<{ src: string; outDir: string }> | undefined): void {
	if ((files?.length ?? 0) >= 2) {
		throw new KipperInvalidInputError(
			"Multiple files are not supported in the CLI. This will be updated in a future release.",
		);
	}
}

/**
 * Evaluates the file or stream provided by the command arguments or flags.
 * @param args The arguments that were passed to the command.
 * @param flags The flags that were passed to the command.
 * @param config The configuration file that was loaded.
 * @since 0.10.0
 */
export async function getParseStream(
	args: OutputArgs,
	flags: OutputFlags<any>,
	config: EvaluatedKipperConfigFile | undefined,
): Promise<{ stream: KipperInputFile | KipperFileStream; outDir: string }> {
	let stream: KipperInputFile | KipperFileStream;
	if (args.file) {
		stream = await KipperInputFile.fromFile(args.file, flags["encoding"] as KipperEncoding);
	} else if (flags["string-code"]) {
		stream = new KipperFileStream({ stringContent: flags["string-code"] });
	} else if (config?.files) {
		ensureCompatibleFiles(config.files);
		stream = await KipperInputFile.fromFile(config.files[0].src, flags["encoding"]);
	} else {
		throw new KipperInvalidInputError("Argument 'file' or flag '-s/--string-code' must be populated");
	}

	return {
		stream: stream,
		outDir: args["output-dir"] ?? config?.outDir ?? "build",
	};
}

/**
 * Input file which represents a file that can be provided as an argument to the
 * {@link KipperCompiler}. This file implements a file stream, which stores the
 * content of the file.
 * @since 0.0.2
 */
export class KipperInputFile extends KipperFileStream {
	public static SPECIAL_CHARACTER_REPLACE_REGEX =
		/[\x00-\x09\x0B-\x1F\x7F-\x9F\xAD\u0378\u0379\u037F-\u0383\u038B\u038D\u03A2\u0528-\u0530\u0557\u0558\u0560\u0588\u058B-\u058E\u0590\u05C8-\u05CF\u05EB-\u05EF\u05F5-\u0605\u061C\u061D\u06DD\u070E\u070F\u074B\u074C\u07B2-\u07BF\u07FB-\u07FF\u082E\u082F\u083F\u085C\u085D\u085F-\u089F\u08A1\u08AD-\u08E3\u08FF\u0978\u0980\u0984\u098D\u098E\u0991\u0992\u09A9\u09B1\u09B3-\u09B5\u09BA\u09BB\u09C5\u09C6\u09C9\u09CA\u09CF-\u09D6\u09D8-\u09DB\u09DE\u09E4\u09E5\u09FC-\u0A00\u0A04\u0A0B-\u0A0E\u0A11\u0A12\u0A29\u0A31\u0A34\u0A37\u0A3A\u0A3B\u0A3D\u0A43-\u0A46\u0A49\u0A4A\u0A4E-\u0A50\u0A52-\u0A58\u0A5D\u0A5F-\u0A65\u0A76-\u0A80\u0A84\u0A8E\u0A92\u0AA9\u0AB1\u0AB4\u0ABA\u0ABB\u0AC6\u0ACA\u0ACE\u0ACF\u0AD1-\u0ADF\u0AE4\u0AE5\u0AF2-\u0B00\u0B04\u0B0D\u0B0E\u0B11\u0B12\u0B29\u0B31\u0B34\u0B3A\u0B3B\u0B45\u0B46\u0B49\u0B4A\u0B4E-\u0B55\u0B58-\u0B5B\u0B5E\u0B64\u0B65\u0B78-\u0B81\u0B84\u0B8B-\u0B8D\u0B91\u0B96-\u0B98\u0B9B\u0B9D\u0BA0-\u0BA2\u0BA5-\u0BA7\u0BAB-\u0BAD\u0BBA-\u0BBD\u0BC3-\u0BC5\u0BC9\u0BCE\u0BCF\u0BD1-\u0BD6\u0BD8-\u0BE5\u0BFB-\u0C00\u0C04\u0C0D\u0C11\u0C29\u0C34\u0C3A-\u0C3C\u0C45\u0C49\u0C4E-\u0C54\u0C57\u0C5A-\u0C5F\u0C64\u0C65\u0C70-\u0C77\u0C80\u0C81\u0C84\u0C8D\u0C91\u0CA9\u0CB4\u0CBA\u0CBB\u0CC5\u0CC9\u0CCE-\u0CD4\u0CD7-\u0CDD\u0CDF\u0CE4\u0CE5\u0CF0\u0CF3-\u0D01\u0D04\u0D0D\u0D11\u0D3B\u0D3C\u0D45\u0D49\u0D4F-\u0D56\u0D58-\u0D5F\u0D64\u0D65\u0D76-\u0D78\u0D80\u0D81\u0D84\u0D97-\u0D99\u0DB2\u0DBC\u0DBE\u0DBF\u0DC7-\u0DC9\u0DCB-\u0DCE\u0DD5\u0DD7\u0DE0-\u0DF1\u0DF5-\u0E00\u0E3B-\u0E3E\u0E5C-\u0E80\u0E83\u0E85\u0E86\u0E89\u0E8B\u0E8C\u0E8E-\u0E93\u0E98\u0EA0\u0EA4\u0EA6\u0EA8\u0EA9\u0EAC\u0EBA\u0EBE\u0EBF\u0EC5\u0EC7\u0ECE\u0ECF\u0EDA\u0EDB\u0EE0-\u0EFF\u0F48\u0F6D-\u0F70\u0F98\u0FBD\u0FCD\u0FDB-\u0FFF\u10C6\u10C8-\u10CC\u10CE\u10CF\u1249\u124E\u124F\u1257\u1259\u125E\u125F\u1289\u128E\u128F\u12B1\u12B6\u12B7\u12BF\u12C1\u12C6\u12C7\u12D7\u1311\u1316\u1317\u135B\u135C\u137D-\u137F\u139A-\u139F\u13F5-\u13FF\u169D-\u169F\u16F1-\u16FF\u170D\u1715-\u171F\u1737-\u173F\u1754-\u175F\u176D\u1771\u1774-\u177F\u17DE\u17DF\u17EA-\u17EF\u17FA-\u17FF\u180F\u181A-\u181F\u1878-\u187F\u18AB-\u18AF\u18F6-\u18FF\u191D-\u191F\u192C-\u192F\u193C-\u193F\u1941-\u1943\u196E\u196F\u1975-\u197F\u19AC-\u19AF\u19CA-\u19CF\u19DB-\u19DD\u1A1C\u1A1D\u1A5F\u1A7D\u1A7E\u1A8A-\u1A8F\u1A9A-\u1A9F\u1AAE-\u1AFF\u1B4C-\u1B4F\u1B7D-\u1B7F\u1BF4-\u1BFB\u1C38-\u1C3A\u1C4A-\u1C4C\u1C80-\u1CBF\u1CC8-\u1CCF\u1CF7-\u1CFF\u1DE7-\u1DFB\u1F16\u1F17\u1F1E\u1F1F\u1F46\u1F47\u1F4E\u1F4F\u1F58\u1F5A\u1F5C\u1F5E\u1F7E\u1F7F\u1FB5\u1FC5\u1FD4\u1FD5\u1FDC\u1FF0\u1FF1\u1FF5\u1FFF\u200B-\u200F\u202A-\u202E\u2060-\u206F\u2072\u2073\u208F\u209D-\u209F\u20BB-\u20CF\u20F1-\u20FF\u218A-\u218F\u23F4-\u23FF\u2427-\u243F\u244B-\u245F\u2700\u2B4D-\u2B4F\u2B5A-\u2BFF\u2C2F\u2C5F\u2CF4-\u2CF8\u2D26\u2D28-\u2D2C\u2D2E\u2D2F\u2D68-\u2D6E\u2D71-\u2D7E\u2D97-\u2D9F\u2DA7\u2DAF\u2DB7\u2DBF\u2DC7\u2DCF\u2DD7\u2DDF\u2E3C-\u2E7F\u2E9A\u2EF4-\u2EFF\u2FD6-\u2FEF\u2FFC-\u2FFF\u3040\u3097\u3098\u3100-\u3104\u312E-\u3130\u318F\u31BB-\u31BF\u31E4-\u31EF\u321F\u32FF\u4DB6-\u4DBF\u9FCD-\u9FFF\uA48D-\uA48F\uA4C7-\uA4CF\uA62C-\uA63F\uA698-\uA69E\uA6F8-\uA6FF\uA78F\uA794-\uA79F\uA7AB-\uA7F7\uA82C-\uA82F\uA83A-\uA83F\uA878-\uA87F\uA8C5-\uA8CD\uA8DA-\uA8DF\uA8FC-\uA8FF\uA954-\uA95E\uA97D-\uA97F\uA9CE\uA9DA-\uA9DD\uA9E0-\uA9FF\uAA37-\uAA3F\uAA4E\uAA4F\uAA5A\uAA5B\uAA7C-\uAA7F\uAAC3-\uAADA\uAAF7-\uAB00\uAB07\uAB08\uAB0F\uAB10\uAB17-\uAB1F\uAB27\uAB2F-\uABBF\uABEE\uABEF\uABFA-\uABFF\uD7A4-\uD7AF\uD7C7-\uD7CA\uD7FC-\uF8FF\uFA6E\uFA6F\uFADA-\uFAFF\uFB07-\uFB12\uFB18-\uFB1C\uFB37\uFB3D\uFB3F\uFB42\uFB45\uFBC2-\uFBD2\uFD40-\uFD4F\uFD90\uFD91\uFDC8-\uFDEF\uFDFE\uFDFF\uFE1A-\uFE1F\uFE27-\uFE2F\uFE53\uFE67\uFE6C-\uFE6F\uFE75\uFEFD-\uFF00\uFFBF-\uFFC1\uFFC8\uFFC9\uFFD0\uFFD1\uFFD8\uFFD9\uFFDD-\uFFDF\uFFE7\uFFEF-\uFFFB\uFFFE\uFFFF]/g;
	private readonly _absolutePath: string;
	private readonly _encoding: BufferEncoding;
	private readonly _path: path.ParsedPath;

	constructor(stringContent: string, fileLocation: string, fileName: string, encoding: BufferEncoding) {
		super({ stringContent: stringContent, name: fileName, filePath: fileLocation });
		this._absolutePath = path.resolve(fileLocation);
		this._encoding = encoding;
		this._path = path.parse(this._absolutePath);
	}

	/**
	 * Returns the absolute Path of the file.
	 */
	public get absolutePath(): string {
		return this._absolutePath;
	}

	/**
	 * An alternative name to {@link absolutePath}, but this path may be relative.
	 * @since 0.1.0
	 */
	public override get filePath(): string {
		return super.filePath;
	}

	/**
	 * Returns the encoding for this specific file
	 */
	public get encoding(): BufferEncoding {
		return this._encoding;
	}

	/**
	 * Returns the path as a {@link path.ParsedPath} instance.
	 * @since 0.1.0
	 */
	public get path(): path.ParsedPath {
		return this._path;
	}

	/**
	 * Creates a new {@link KipperInputFile} instance based on the content of the {@link filePath}
	 * @param filePath The path to the file that should be read
	 * @param encoding The encoding that should be used to read the file
	 * @returns The new {@link KipperInputFile} instance with the set values
	 * @since 0.1.0
	 */
	public static async fromFile(filePath: string, encoding: KipperEncoding = "utf8"): Promise<KipperInputFile> {
		const fileLocation = path.resolve(filePath);
		const name = (() => {
			const items1 = fileLocation.split("\\");
			const items2 = items1[items1.length - 1].split("/");
			return items2[items2.length - 1];
		})();

		// Ensure the file can be accessed
		try {
			await fs.access(fileLocation, constants.R_OK);
		} catch (e) {
			throw new KipperFileAccessError(fileLocation);
		}

		// Read in the content of the file
		let content: string = (await fs.readFile(fileLocation, encoding as BufferEncoding)).toString();

		// Standardising the line endings to '\n'
		content = content.replace(/(\r(\n)?)/gi, "\n");

		// Remove non-printable unicode characters
		content = content.replace(KipperInputFile.SPECIAL_CHARACTER_REPLACE_REGEX, "");

		return new KipperInputFile(content, fileLocation, name, encoding as BufferEncoding);
	}
}