import {Injectable, ScopedContainer, Container} from '../../di'
import {infer, UniversalPath} from '../../util'
import {IncomingMessage, ServerResponse} from 'http'
import {HTTPCookieJar} from '../kernel/HTTPCookieJar'
import {TLSSocket} from 'tls'
import * as url from 'url'
import {Response} from './Response'
import * as Negotiator from 'negotiator'

/**
 * Enumeration of different HTTP verbs.
 * @todo add others?
 */
export type HTTPMethod = 'post' | 'get' | 'patch' | 'put' | 'delete' | 'unknown';

/**
 * Returns true if the given item is a valid HTTP verb.
 * @param what
 */
export function isHTTPMethod(what: unknown): what is HTTPMethod {
    return ['post', 'get', 'patch', 'put', 'delete'].includes(String(what))
}

/**
 * Interface that describes the HTTP protocol version.
 */
export interface HTTPProtocol {
    string: string,
    major: number,
    minor: number,
}

/**
 * Interface that describes the origin IP address of a request.
 */
export interface HTTPSourceAddress {
    address: string;
    family: 'IPv4' | 'IPv6';
    port: number;
}

/**
 * Interface describing a container that holds user input data.
 */
export interface DataContainer {
    input(key?: string): any
}

/**
 * A class that represents an HTTP request from a client.
 */
@Injectable()
export class Request extends ScopedContainer implements DataContainer {

    /** The cookie manager for the request. */
    public readonly cookies: HTTPCookieJar;

    /** The URL suffix of the request. */
    public readonly url: string;

    /** The fully-qualified URL of the request. */
    public readonly fullUrl: string;

    /** The HTTP verb of the request. */
    public readonly method: HTTPMethod;

    /** True if the request was made via TLS. */
    public readonly secure: boolean;

    /** The request HTTP protocol version. */
    public readonly protocol: HTTPProtocol;

    /** The URL path, stripped of query params. */
    public readonly path: string;

    /** The raw parsed query data from the request. */
    public readonly rawQueryData: {[key: string]: string | string[] | undefined};

    /** The inferred query data. */
    public readonly query: {[key: string]: any};

    /** True if the request was made via XMLHttpRequest. */
    public readonly isXHR: boolean;

    /** The origin IP address of the request. */
    public readonly address: HTTPSourceAddress;

    /** The associated response. */
    public readonly response: Response;

    /** The media types accepted by the client. */
    public readonly mediaTypes: string[];

    /** Input parsed from the request */
    public readonly parsedInput: {[key: string]: any} = {}

    /** Files parsed from the request. */
    public readonly uploadedFiles: {[key: string]: UniversalPath} = {}

    /** If true, the response lifecycle will not time out and send errors. */
    public bypassTimeout = false

    constructor(
        /** The native Node.js request. */
        protected clientRequest: IncomingMessage,

        /** The native Node.js response. */
        protected serverResponse: ServerResponse,
    ) {
        super(Container.getContainer())

        this.secure = Boolean((clientRequest.connection as TLSSocket).encrypted)

        this.cookies = new HTTPCookieJar(this)
        this.url = String(clientRequest.url)
        this.fullUrl = (this.secure ? 'https' : 'http') + `://${this.getHeader('host')}${this.url}`

        const method = clientRequest.method?.toLowerCase()
        this.method = isHTTPMethod(method) ? method : 'unknown'

        this.protocol = {
            string: clientRequest.httpVersion,
            major: clientRequest.httpVersionMajor,
            minor: clientRequest.httpVersionMinor,
        }

        this.register(Request)
        this.instances.push({
            key: Request,
            value: this,
        })

        const parts = url.parse(this.url, true)

        this.path = parts.pathname ?? '/'
        this.rawQueryData = parts.query

        const query: {[key: string]: any} = {}
        for ( const key in this.rawQueryData ) {
            if ( !Object.prototype.hasOwnProperty.call(this.rawQueryData, key) ) {
                continue
            }

            const value = this.rawQueryData[key]

            if ( Array.isArray(value) ) {
                query[key] = value.map(x => infer(x))
            } else if ( value ) {
                query[key] = infer(value)
            } else {
                query[key] = value
            }
        }

        this.query = query
        this.isXHR = String(this.clientRequest.headers['x-requested-with']).toLowerCase() === 'xmlhttprequest'

        const {address = '0.0.0.0', family = 'IPv4', port = 0} = this.clientRequest.connection.address() as any
        this.address = {
            address,
            family,
            port,
        }

        this.mediaTypes = (new Negotiator(clientRequest)).mediaTypes()
        this.response = new Response(this, serverResponse)
    }

    /** Get the value of a header, if it exists. */
    public getHeader(name: string): string | string[] | undefined {
        return this.clientRequest.headers[name.toLowerCase()]
    }

    /** Get the native Node.js IncomingMessage object. */
    public toNative(): IncomingMessage {
        return this.clientRequest
    }

    /**
     * Get the value of an input field on the request. Spans multiple input sources.
     * @param key
     */
    public input(key?: string): unknown {
        if ( !key ) {
            return {
                ...this.parsedInput,
                ...this.query,
                ...this.uploadedFiles,
            }
        }

        if ( key in this.parsedInput ) {
            return this.parsedInput[key]
        }

        if ( key in this.query ) {
            return this.query[key]
        }
    }

    /**
     * Get the UniversalPath instance for a file uploaded in the given field on the request.
     */
    public file(key: string): UniversalPath | undefined {
        return this.uploadedFiles[key]
    }

    /**
     * Returns true if the request accepts the given media type.
     * @param type - a mimetype, or the short forms json, xml, or html
     */
    accepts(type: string): boolean {
        if ( type === 'json' ) {
            type = 'application/json'
        } else if ( type === 'xml' ) {
            type = 'application/xml'
        } else if ( type === 'html' ) {
            type = 'text/html'
        }

        type = type.toLowerCase()

        const possible = [
            type,
            type.split('/')[0] + '/*',
            '*/*',
        ]

        return this.mediaTypes.some(media => possible.includes(media.toLowerCase()))
    }

    /**
     * Returns the short form of the content type the client has requested.
     */
    wants(): 'html' | 'json' | 'xml' | 'unknown' {
        const jsonIdx = this.mediaTypes.indexOf('application/json') ?? this.mediaTypes.indexOf('application/*') ?? this.mediaTypes.indexOf('*/*')
        const xmlIdx = this.mediaTypes.indexOf('application/xml') ?? this.mediaTypes.indexOf('application/*') ?? this.mediaTypes.indexOf('*/*')
        const htmlIdx = this.mediaTypes.indexOf('text/html') ?? this.mediaTypes.indexOf('text/*') ?? this.mediaTypes.indexOf('*/*')

        if ( htmlIdx >= 0 && htmlIdx <= jsonIdx && htmlIdx <= xmlIdx ) {
            return 'html'
        }
        if ( jsonIdx >= 0 && jsonIdx <= htmlIdx && jsonIdx <= xmlIdx ) {
            return 'json'
        }
        if ( xmlIdx >= 0 && xmlIdx <= jsonIdx && xmlIdx <= htmlIdx ) {
            return 'xml'
        }
        return 'unknown'
    }

    // hostname

    /*
    param
    json
    fresh/stale - cache
    remote ips (proxy)
    signedCookies
    accepts charsets, encodings, languages
    range header parser
     */
}