daton/lib/src/support/UniversalPath.ts

import { path as deno_path } from '../external/std.ts'
import * as Mime from 'https://deno.land/x/media_types/mod.ts'

export enum UniversalPathPrefix {
    HTTP = 'http://',
    HTTPS = 'https://',
    Local = 'file://',
}

export type PathLike = string | UniversalPath

export function universal_path(...parts: PathLike[]): UniversalPath {
    let [main, ...concats] = parts
    if ( !(main instanceof UniversalPath) ) main = new UniversalPath(main)
    return main.concat(...concats)
}

export class UniversalPath {
    protected _prefix!: UniversalPathPrefix
    protected _local!: string

    constructor(
        protected readonly initial: string,
    ) {
        this.set_prefix()
        this.set_local()
    }

    protected set_prefix() {
        if ( this.initial.toLowerCase().startsWith('http://') ) {
            this._prefix = UniversalPathPrefix.HTTP
        } else if ( this.initial.toLowerCase().startsWith('https://') ) {
            this._prefix = UniversalPathPrefix.HTTPS
        } else {
            this._prefix = UniversalPathPrefix.Local
        }
    }

    protected set_local() {
        this._local = this.initial
        if ( this.initial.toLowerCase().startsWith(this._prefix) ) {
            this._local = this._local.slice(this._prefix.length)
        }

        if ( this._prefix === UniversalPathPrefix.Local && !this._local.startsWith('/') ) {
            this._local = deno_path.resolve(this._local)
        }
    }

    get prefix() {
        return this._prefix
    }

    get is_local() {
        return this._prefix === UniversalPathPrefix.Local
    }

    get is_remote() {
        return this._prefix !== UniversalPathPrefix.Local
    }

    get unqualified() {
        return this._local
    }

    get to_local() {
        if ( this.is_local ) {
            return this._local
        } else {
            return `${this.prefix}${this._local}`
        }
    }

    get to_remote() {
        return `${this.prefix}${this._local}`
    }

    public concat(...paths: PathLike[]): UniversalPath {
        const resolved = deno_path.join(this.unqualified, ...(paths.map(p => typeof p === 'string' ? p : p.unqualified)))
        return new UniversalPath(`${this.prefix}${resolved}`)
    }

    public append(path: PathLike): this {
        this._local += String(path)
        return this
    }

    toString() {
        return `${this.prefix}${this._local}`
    }

    get ext() {
        return deno_path.extname(this._local)
    }

    get mime_type() {
        return Mime.lookup(this.ext)
    }

    get content_type() {
        return Mime.contentType(this.ext)
    }

    get charset() {
        if ( this.mime_type ) {
            return Mime.charset(this.mime_type)
        }
    }
}