import type { ConnectRequest, SignTransactionRequest, WebApp } from "./types";
import type { InjectionConfig } from "./types";
import { WalletStore } from "./store";
import type { Injected, InjectedAccount, InjectedExtension, InjectedMetadataKnown, InjectedWindowProvider } from "@polkadot/extension-inject/types";
import { encodeRequest } from "./encryption";
import { SignerPayloadRaw, SignerResult } from "@polkadot/types/types";
import { generateRequestId, parseSignedTxFromStartParam, parseWalletsFromStartParam } from "./helpers";
import { mockAccountsSubscribe } from "./constants";

export class Wallet implements InjectedWindowProvider {
    private readonly varanWalletUrl!: string;
    private readonly store: WalletStore;
    private readonly name = 'Varan Wallet';
    private readonly callbackUrl: string;
    private readonly connectTimeout: number;

    constructor(
        private readonly webApp: WebApp,
        { callbackUrl, isDev, connectTimeout }: Required<InjectionConfig>,
    ) {
        this.varanWalletUrl = isDev ? 'https://t.me/devReptileBot?startapp=' : 'https://t.me/varanwalletbot?startapp=';
        this.store = new WalletStore();
        this.callbackUrl = callbackUrl;
        this.connectTimeout = connectTimeout;
        void this._startParamsCheck();
    }

    get version(): string {
        return '1.0.0';
    }

    private get signer(): InjectedExtension['signer'] {
        return {
            signRaw: (raw) => this.signRawTransaction(raw),
        };
    }

    private async _startParamsCheck(): Promise<void> {
        let actions = 0;
        const newWalletAddresses = parseWalletsFromStartParam(this.webApp);
        const currentAccounts = await this.accounts;

        if (newWalletAddresses) {
            const allWallets = Array.from(
                new Set(
                    currentAccounts
                        .map(a => a.address)
                        .concat(newWalletAddresses)
                    )
                )

            this.store.set('accounts', allWallets);
            actions += 1;
        }

        const tx = parseSignedTxFromStartParam(this.webApp);

        if (tx) {
            const currentTransactions = this.store.get('transactions');

            const pendingTransactionIndex = currentTransactions.findIndex(t => t.id === tx.id && t.status === 'signing');
            if (pendingTransactionIndex === -1) return;

            currentTransactions[pendingTransactionIndex] = {
                ...currentTransactions[pendingTransactionIndex],
                status: tx.success ? 'success' : 'failed',
                signedTx: tx.signedTx ? tx.signedTx : '',
            };

            this.store.set('transactions', currentTransactions);
            actions += 1;
        }


        if (actions) {
            // this.webApp.close();
        }
    }

    private formatAccount(account: string): InjectedAccount {
        return {
            address: account,
            name: account.slice(0, 6) + '...' + account.slice(-4),
        };
    }

    get accounts(): Promise<InjectedAccount[]> {
        const accounts = this.store.get('accounts');
        return Promise.resolve(accounts.map(this.formatAccount));
    }

    private get extensionAccounts(): InjectedExtension['accounts'] {
        return {
            get: () => this.accounts,
            subscribe: mockAccountsSubscribe
        };
    }

    private get extensionMetadata(): InjectedExtension['metadata'] {
        const metadata = this.store.get('injectedMetadataKnown');
        const setMetadata = async (metadata: InjectedMetadataKnown) => {
            await this.store.set('injectedMetadataKnown', metadata);
            return true;
        };
        if (!metadata) return {
            get: () => Promise.resolve([]),
            provide: setMetadata,
        };
        return {
            get: () => Promise.resolve([metadata]),
            provide: setMetadata,
        };
    }

    private async signRawTransaction(raw: SignerPayloadRaw): Promise<SignerResult> {
        const accounts = await this.accounts;
        if (!accounts.length) throw new Error('No accounts found');

        const address = accounts.find(a => a.address === raw.address);
        if (!address) throw new Error('Provided account was not found');

        const request: SignTransactionRequest = {
            method: 'signTransaction',
            tx: raw.data,
            wallet: raw.address,
            callback: this.callbackUrl,
            id: generateRequestId(),
        };
        
        const encodedRequest = encodeRequest(request);
        const botUrl = `${this.varanWalletUrl}${encodedRequest}`;
        this.store.set('transactions', [{
            id: request.id,
            signedTx: '',
            status: 'signing',
        }]);
        
        this.webApp.openTelegramLink(botUrl);

        return new Promise<SignerResult>((resolve) => {
            const id = this.store.subscribe('transactions', (transactions) => {
                const pendingTransaction = transactions.find(t => t.id === request.id && t.status === 'signing');
                if (pendingTransaction) {
                    this.store.unsubscribe('transactions', id);
                    resolve({
                        id: pendingTransaction.id,
                        signature: pendingTransaction.signedTx,
                    } as SignerResult);
                }
            });
        });
    }

    private async _connect(): Promise<void> {
        const request: ConnectRequest = {
            method: 'connect',
            callback: this.callbackUrl,
        };

        const encodedRequest = encodeRequest(request);
        const botUrl = `${this.varanWalletUrl}${encodedRequest}`;

        await this.webApp.openTelegramLink(botUrl);

        return new Promise<void>((resolve) => {
            const id = this.store.subscribe('accounts', (accounts) => {
                if (accounts.length) {
                    this.store.unsubscribe('accounts', id);
                    resolve();
                }
            });
        });
    }

    async connect(): Promise<InjectedExtension> {
        const accounts = await this.accounts;
        if (!accounts.length) {
            await Promise.race([
                this._connect(),
                new Promise<void>((_, reject) => {
                    setTimeout(() => {
                        reject(new Error('Connect timeout'));
                    }, this.connectTimeout);
                })
            ]);
        }
        
        return Promise.resolve({
            name: this.name,
            version: this.version,
            accounts: this.extensionAccounts,
            signer: this.signer,
            metadata: this.extensionMetadata,
        });
    }

    async enable(): Promise<Injected> {
        const accounts = await this.accounts;
        if (!accounts.length) {
            throw new Error('Please connect first');
        }
        return {
            accounts: this.extensionAccounts,
            signer: this.signer,
            metadata: this.extensionMetadata,
        };
    }
}