import * as fs from 'node:fs';
import { isCppAllowed } from './map';

export const INDENT = '    ';
export const POINTER_SIZE = 4;
export const EXTENSION = '.def';
export const STRUCTURE_FILES: {[id: string]: string} = {};
export function readDefinition(name: string) {
    if (!STRUCTURE_FILES[name]) {
        throw new Error(`Missing Definition File: ${name}${EXTENSION}`);
    }
    return fs.readFileSync(STRUCTURE_FILES[name]!, {encoding: 'utf8'});
}
export function syntaxError(message?: string) {
    throw new Error('Syntax Error' + (message ? `: ${message}` : ''));
}
export function parseTypeAndName(piece: string) {
    // Split On Last Space
    const index = piece.lastIndexOf(' ');
    if (index === -1) {
        syntaxError('Unable To Find Name/Type Divider');
    }
    let name = piece.substring(index + 1)!;
    let type = piece.substring(0, index)!;
    // Move Asterisks From Name To Type
    while (name.startsWith('*')) {
        name = name.substring(1);
        if (!type.endsWith('*')) {
            type += ' ';
        }
        type += '*';
    }
    // Return
    return {type, name};
}
export const MIN_SIZE = 1;
export function toUpperSnakeCase(str: string) {
    let wasUpper = false;
    let nextIsUpper = false;
    let out = '';
    for (let i = 0; i < str.length; i++) {
        let character = str.charAt(i);
        if (character === '_') {
            wasUpper = false;
            nextIsUpper = true;
            continue;
        }
        const isUpper = character === character.toUpperCase() || nextIsUpper;
        nextIsUpper = false;
        character = character.toUpperCase();
        if (isUpper && i > 0 && !wasUpper) {
            out += '_';
        }
        out += character;
        wasUpper = isUpper;
    }
    return out;
}
export function formatType(type: string) {
    if (!type.endsWith('*')) {
        type += ' ';
    }
    return type;
}
export const COMMENT = '//';
export function toHex(x: number) {
    return '0x' + x.toString(16);
}
export function getAssertFunction() {
    return isCppAllowed() ? 'static_assert' : '_Static_assert';
}
export function assertSize(name: string, size: number, isDefined: boolean) {
    let out = '';
    // Define Size Macro
    const macro = toUpperSnakeCase(name) + '_SIZE';
    out += `#define ${macro} ${toHex(size)}\n`;
    // Check Size
    out += `${getAssertFunction()}(sizeof (${name}) == ${macro}, "Invalid Size");\n`;
    // Hide Structure Size If The Real Size Is Unknown
    if (!isDefined) {
        out += `#undef ${macro}\n`;
    }
    // Return
    return out;
}
export function safeParseInt(str: string) {
    const x = parseInt(str);
    if (isNaN(x)) {
        throw new Error('Invalid Integer: ' + str);
    }
    return x;
}
export function stripArrayData(propertyName: string) {
    const index = propertyName.indexOf('[');
    if (index !== -1) {
        propertyName = propertyName.substring(0, index);
    }
    return propertyName;
}
export function getSizeMultiplierFromArrayData(propertyName: string) {
    let multiplier = 1;
    // Check If Array Data Is Present
    const index = propertyName.indexOf('[');
    if (index === -1) {
        return multiplier;
    }
    propertyName = propertyName.substring(index + 1);
    // Strip Last ]
    if (!propertyName.endsWith(']')) {
        syntaxError('Expecting ]');
    } else {
        propertyName = propertyName.substring(0, propertyName.length - 1);
    }
    // Split
    const parts = propertyName.split('][');
    // Calculate Multiplier
    for (const part of parts) {
        multiplier *= safeParseInt(part);
    }
    // Return
    return multiplier;
}
export function getSelfArg(type: string) {
    return `${type} *self`;
}
export class Size {
    #size: number | null;
    #isExact: boolean;
    readonly #pointerAligned: boolean;

    constructor(pointerAligned: boolean) {
        this.#size = null;
        this.#isExact = false;
        this.#pointerAligned = pointerAligned;
    }

    has() {
        return this.#size !== null;
    }
    get() {
        if (this.#size === null) {
            throw new Error('No Size Specified');
        }
        return this.#size;
    }
    set(size: number, isExact: boolean) {
        if (size < MIN_SIZE) {
            throw new Error(`Size Too Small: ${toHex(size)}`);
        }
        if (this.#isExact) {
            throw new Error('Cannot Change Size After Being Set By Base Structure');
        }
        if (this.#size !== null && size < this.#size) {
            throw new Error('Cannot Decrease VTable Size');
        }
        this.#size = size;
        this.#isExact = isExact;
        if (this.#pointerAligned && (this.#size % POINTER_SIZE) !== 0) {
            throw new Error(`Invalid Size: ${toHex(this.#size)}`);
        }
    }
    // Whether This Is An Exact Limit Or Just A Lower Bound
    isExact() {
        return this.#isExact;
    }
}