export class IRCMessage {
    constructor(
        public tags: Map<string, string>,
        public prefix: string,
        public command: string,
        public params: string[],
    ) {}
    toString() {
        let messageString = '';
        if (this.tags.size !== 0) {
            let tagArray = [];
            for (const [key, value] of this.tags) {
                if (value === '') {
                    tagArray.push(key);
                }
                else {
                    tagArray.push(`${key}=${encodeTag(value)}`);
                }
            }
            messageString = `@${tagArray.join(";")} `;
        }

        if (this.prefix) {
            messageString = `${messageString}:${this.prefix} `;
        }

        messageString = `${messageString}${this.command}`;

        const params = this.params.slice();

        let lastParam = params.pop();
        if (lastParam) {
            if (lastParam.indexOf(' ') !== -1) {
                lastParam = `:${lastParam}`;
            }
            params.push(lastParam);
        }
        messageString = `${messageString} ${params.join(' ')}`;
        return messageString;
    }
}

function decodeTag(value: string): string {
    const tagDecodeMap = new Map([
        ['\\:', ';'],
        ['\\s', ' '],
        ['\\\\', '\\'],
        ['\\r', '\r'],
        ['\\n', '\n'],
        ['\\', ''],
    ]);
    return value.replace(/\\:|\\s|\\\\|\\r|\\n|\\/gi, t => tagDecodeMap.get(t) || '')
}

function encodeTag(value: string): string {
    const tagEncodeMap = new Map([
        [';', '\\:'],
        [' ', '\\s'],
        ['\\', '\\\\'],
        ['\r', '\\r'],
        ['\n', '\\n'],
    ]);
    return value.replace(/;| |\\|\r|\n/gi, t => tagEncodeMap.get(t) || '');
}

function addToTags(key: string): boolean {
    const tagsToPass = [
        'batch',
        'reflectionircd.chat/delete-message',
        'reflectionircd.chat/edit-message',
        'label',
    ]
    return (tagsToPass.includes(key) || key.startsWith('+'));
}

export function parseIRCMessage(rawLine: string) {
    //console.log(`RAW: ${rawLine}`);
    let restOfMessage = rawLine;
    let parsedTags: Map<string, string> = new Map();
    let prefix = '';
    let command = '';
    let params: string[] = [];
    if (rawLine.startsWith('@')) {
        const tags = restOfMessage.substring(1, restOfMessage.indexOf(' '));
        restOfMessage = restOfMessage.substring(restOfMessage.indexOf(' ')+1);
        for (const tag of tags.split(';')) {
            const valueSplit = tag.indexOf('=');
            if (valueSplit === -1 && addToTags(tag)) {
                parsedTags.set(tag, '');
                continue;
            }
            const key = tag.substring(0, valueSplit);
            const value = tag.substring(valueSplit+1);
            if (addToTags(key))
                parsedTags.set(key, decodeTag(value));
        }
    }
    if (restOfMessage.startsWith(':')) {
        prefix = restOfMessage.substring(0, restOfMessage.indexOf(' '));
        restOfMessage = restOfMessage.substring(restOfMessage.indexOf(' ')+1);
    }

    if (restOfMessage.indexOf(' ') === -1) {
        command = restOfMessage;
        return new IRCMessage(parsedTags, prefix, command, params);
    }

    command = restOfMessage.substring(0, restOfMessage.indexOf(' '));
    restOfMessage = restOfMessage.substring(restOfMessage.indexOf(' ') + 1);

    let lastParam = '';
    if (restOfMessage.indexOf(' :') !== -1) {
        lastParam = restOfMessage.substring(restOfMessage.indexOf(' :') + 2);
        restOfMessage = restOfMessage.substring(0, restOfMessage.indexOf(' :'));
    }

    params = restOfMessage.split(' ');
    if (lastParam !== '') {
        params.push(lastParam);
    }
    //console.log(parsedTags, prefix, command, params);
    return new IRCMessage(parsedTags, prefix, command, params);
}