"use strict";

export class Domain {
    name;
    id;
    servers;
    invalidServers;

    toString() {
        return `[${this.name}]`;
    }

    constructor(jsonData, domainServers) {
        // FIXME check values
        this.name = jsonData.name;
        this.id = jsonData.id;
        this.servers = [];
        for (let domainServer of domainServers) {
            this.servers.push(new DomainServer(domainServer));
        }
        this.invalidServers = [];
    }

    static async fromName(domainName) {
        return fetch(`https://${domainName}/.well-known/usimp.json`, {
            redirect: "manual",
        }).then(response => {
            if (response.ok) {
                return response.json();
            } else {
                throw "Invalid response";
            }
        }).then(data => {
            return new Domain(data.domain, data.domain_servers);
        });
    }

    chooseDomainServer() {
        if (this.servers.length === 0) throw Error("No domain servers specified");

        this.servers.filter(srv => this.invalidServers.map(srv => srv.id).includes(srv.id));
        if (this.servers.length === 0) throw Error("No domain servers reachable");
        if (this.servers.length === 1) return this.servers[0];

        let priority = this.servers.reduce((min, srv) => Math.min(min, srv.priority), Infinity);
        let domainServers = this.servers.filter(srv => srv.priority === priority);
        if (domainServers.length === 1) return this.servers[0];

        let totalWeight = domainServers.reduce((total, srv) => total + srv.weight, 0);
        let w = Math.floor(Math.random() * totalWeight);

        let accumulator = 0;
        for (let srv of domainServers) {
            accumulator += srv.weight;
            if (w < accumulator) return srv;
        }

        throw "Domain server selection did not work correctly";
    }
}

export class DomainServer {
    host;
    id;
    priority;
    weight;
    protocols;

    toString() {
        return `[${this.host}/${this.priority}/${this.weight}]`;
    }

    constructor(jsonData) {
        // FIXME check values
        this.host = jsonData.host;
        this.id = jsonData.id;
        this.priority = jsonData.priority;
        this.weight = jsonData.weight;
        this.protocols = jsonData.protocols;
    }
}

export class Account {

}

export class Member {

}

export class Room {

}

export class Event {

}

export class Session {
    domain;
    server;
    token;

    httpBaseUrl;
    wsConnection;
    numRequests;

    constructor(domain) {
        this.domain = domain;
        this.server = domain.chooseDomainServer();
        this.numRequests = 0;

        const host = this.server.host;
        const protocols = this.server.protocols;

        /*
        if ("wss" in protocols) {
            this.wsConnection = new WebSocket(`wss://${host}:${protocols.wss}/_usimp/websocket`, ["usimp"]);
        } else if ("ws" in protocols) {
            this.wsConnection = new WebSocket(`ws://${host}:${protocols.ws}/_usimp/websocket`, ["usimp"])
        }
        */

        if ("https" in protocols) {
            this.httpBaseUrl = `https://${host}:${protocols.https}/_usimp`;
        } else if ("http" in protocols) {
            this.httpBaseUrl = `http://${host}:${protocols.http}/_usimp`;
        } else {
            throw "Domain server provides no supported transport protocols";
        }
    }

    send(endpoint, data) {
        this.numRequests++;
        if (this.wsConnection) {
            this.wsConnection.send(JSON.stringify({
                'request_num': this.numRequests,
                'data': data
            }));
        } else {
            let headers = {
                'Content-Type': 'application/json',
                'To-Domain': this.domain.id,
                'From-Domain': this.domain.id,
            };
            if (this.token) {
                headers['Authorization'] = `usimp ${this.token}`;
            }

            return fetch(`${this.httpBaseUrl}/${endpoint}`, {
                method: "POST",
                headers: headers,
                body: JSON.stringify(data),
            }).then(response => {
                return response.json();
            });
        }
    }

    authenticate(accountName, password) {
        return this.send("authenticate", {
            type: "password",
            name: accountName,
            password: password,
        }).then(response => {
            this.token = response.token;
            return response;
        });
    }

    sendEvent(roomId, data) {
        return this.send("send_event", {
            room_id: roomId,
            data: data,
        });
    }

    subscribe(func) {
        this.numRequests++;
        if (this.wsConnection) {
            // TODO
        } else {
            let headers = {
                'Content-Type': 'application/json',
                'To-Domain': this.domain.id,
                'From-Domain': this.domain.id,
            };
            if (this.token) {
                headers['Authorization'] = `usimp ${this.token}`;
            }

            fetch(`${this.httpBaseUrl}/subscribe`, {
                method: "POST",
                headers: headers,
                body: JSON.stringify({}),
            }).then(response => {
                return response.json();
            }).then(response => {
                func(response);
                this.subscribe(func);
            });
        }
    }
}