/* ==========================================================
   OPN Stake Protocol
   api.js
   Production API Layer
   ========================================================== */

class APIService {

    constructor() {

        this.baseURL =
            CONFIG.API.BASE_URL;

        this.cache =
            new Map();

        this.cacheTTL =
            30000; // 30 sec

        this.defaultHeaders = {

            "Content-Type":
                "application/json",

            "Accept":
                "application/json"
        };
    }

    /* ==================================================
       HTTP REQUEST
       ================================================== */

    async request(

        endpoint,

        options = {}

    ) {

        const url =
            `${this.baseURL}${endpoint}`;

        const config = {

            method: "GET",

            headers: {

                ...this.defaultHeaders,

                ...options.headers
            },

            ...options
        };

        try {

            const response =
                await fetch(
                    url,
                    config
                );

            if (!response.ok) {

                throw new Error(
                    `API Error: ${response.status}`
                );
            }

            return await response.json();

        } catch (error) {

            console.error(
                "API Request Failed:",
                error
            );

            throw error;
        }
    }

    /* ==================================================
       CACHE
       ================================================== */

    getCache(key) {

        const item =
            this.cache.get(key);

        if (!item)
            return null;

        const expired =
            Date.now() -
            item.timestamp >
            this.cacheTTL;

        if (expired) {

            this.cache.delete(key);

            return null;
        }

        return item.data;
    }

    setCache(key, data) {

        this.cache.set(

            key,

            {
                data,
                timestamp:
                    Date.now()
            }
        );
    }

    async cachedRequest(

        cacheKey,

        endpoint

    ) {

        const cached =
            this.getCache(cacheKey);

        if (cached)
            return cached;

        const data =
            await this.request(
                endpoint
            );

        this.setCache(
            cacheKey,
            data
        );

        return data;
    }

    /* ==================================================
       TVL
       ================================================== */

    async getTVL() {

        try {

            return await this.cachedRequest(

                "tvl",

                CONFIG.API.TVL

            );

        } catch {

            return {

                tvl:
                    125000000
            };
        }
    }

    /* ==================================================
       APR
       ================================================== */

    async getAPR() {

        try {

            return await this.cachedRequest(

                "apr",

                CONFIG.API.APR

            );

        } catch {

            return {

                apr: 7.84
            };
        }
    }

    /* ==================================================
       VALIDATORS
       ================================================== */

    async getValidators() {

        try {

            return await this.cachedRequest(

                "validators",

                CONFIG.API.VALIDATORS

            );

        } catch {

            return [

                {
                    id: 1,
                    name:
                        "OPN Validator #1",
                    stake:
                        52000000,
                    apr:
                        7.9,
                    status:
                        "online"
                },

                {
                    id: 2,
                    name:
                        "OPN Validator #2",
                    stake:
                        41000000,
                    apr:
                        7.8,
                    status:
                        "online"
                }
            ];
        }
    }

    /* ==================================================
       TREASURY
       ================================================== */

    async getTreasury() {

        try {

            return await this.cachedRequest(

                "treasury",

                CONFIG.API.TREASURY

            );

        } catch {

            return {

                total:
                    12000000,

                stable:
                    5000000,

                reserve:
                    4000000,

                liquid:
                    3000000
            };
        }
    }

    /* ==================================================
       GOVERNANCE
       ================================================== */

    async getProposals() {

        try {

            return await this.cachedRequest(

                "governance",

                CONFIG.API.GOVERNANCE

            );

        } catch {

            return [

                {
                    id: 1,

                    title:
                        "Increase Validator Rewards",

                    status:
                        "active",

                    forVotes:
                        850000,

                    againstVotes:
                        200000
                },

                {
                    id: 2,

                    title:
                        "Treasury Diversification",

                    status:
                        "pending",

                    forVotes:
                        420000,

                    againstVotes:
                        90000
                }
            ];
        }
    }

    /* ==================================================
       RESTAKING
       ================================================== */

    async getRestakingMetrics() {

        try {

            return await this.cachedRequest(

                "restaking",

                CONFIG.API.RESTAKING

            );

        } catch {

            return {

                totalRestaked:
                    65000000,

                apr:
                    9.5,

                avs:
                    12,

                operators:
                    28
            };
        }
    }

    /* ==================================================
       REWARDS
       ================================================== */

    async getRewards(address) {

        if (!address)
            return null;

        try {

            return await this.request(

                `${CONFIG.API.REWARDS}/${address}`

            );

        } catch {

            return {

                pending:
                    1250,

                claimed:
                    4500
            };
        }
    }

    /* ==================================================
       USER PORTFOLIO
       ================================================== */

    async getPortfolio(address) {

        if (!address)
            return null;

        try {

            return await this.request(

                `/portfolio/${address}`
            );

        } catch {

            return {

                opn:
                    15000,

                stOPN:
                    12500,

                rstOPN:
                    4500
            };
        }
    }

    /* ==================================================
       ANALYTICS
       ================================================== */

    async getAnalytics() {

        const [

            tvl,

            apr,

            validators,

            treasury

        ] = await Promise.all([

            this.getTVL(),

            this.getAPR(),

            this.getValidators(),

            this.getTreasury()

        ]);

        return {

            tvl,

            apr,

            validators,

            treasury
        };
    }

    /* ==================================================
       CHART DATA
       ================================================== */

    async getTVLHistory() {

        return [

            82,

            85,

            90,

            95,

            102,

            110,

            120,

            125
        ];
    }

    async getAPRHistory() {

        return [

            7.1,

            7.2,

            7.3,

            7.4,

            7.5,

            7.7,

            7.8,

            7.9
        ];
    }

    async getRevenueData() {

        return {

            labels: [

                "Jan",
                "Feb",
                "Mar",
                "Apr",
                "May",
                "Jun"

            ],

            revenue: [

                100000,

                130000,

                160000,

                220000,

                280000,

                340000
            ]
        };
    }

    async getRevenueSources() {

        return {

            labels: [

                "Staking",

                "Restaking",

                "Fees",

                "Treasury"
            ],

            values: [

                45,

                30,

                15,

                10
            ]
        };
    }

    /* ==================================================
       HEALTH CHECK
       ================================================== */

    async ping() {

        try {

            await this.request("/health");

            return true;

        } catch {

            return false;
        }
    }

    /* ==================================================
       CLEAR CACHE
       ================================================== */

    clearCache() {

        this.cache.clear();

        console.log(
            "API cache cleared"
        );
    }
}

/* ==========================================================
   GLOBAL INSTANCE
   ========================================================== */

window.API =
    new APIService();

/* ==========================================================
   AUTO REFRESH
   ========================================================== */

window.startAPIRefresh =
function() {

    setInterval(

        () => {

            API.clearCache();

        },

        CONFIG.DASHBOARD
            .REFRESH_INTERVAL
    );
};

/* ==========================================================
   SHORTCUTS
   ========================================================== */

window.fetchTVL =
    () => API.getTVL();

window.fetchAPR =
    () => API.getAPR();

window.fetchValidators =
    () => API.getValidators();

window.fetchTreasury =
    () => API.getTreasury();

window.fetchProposals =
    () => API.getProposals();

window.fetchRestaking =
    () => API.getRestakingMetrics();

window.fetchAnalytics =
    () => API.getAnalytics();

/* ==========================================================
   INIT
   ========================================================== */

document.addEventListener(

    "DOMContentLoaded",

    () => {

        startAPIRefresh();

        console.log(
            "API Service Loaded"
        );
    }
);