import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { JwtService } from '@nestjs/jwt';
import { GatiService } from '@nxtoai/gati';
import { AagService } from '@nxtoai/aag';

@Injectable()
export class JwtHelper {
    private readonly TOKEN_PREFIX = 'token:';
    private readonly USER_PREFIX = 'user:';
    private readonly TOKEN_EXPIRY = 24 * 60 * 60; // 24 hours in seconds

    constructor(
        private readonly configService: ConfigService,
        private readonly jwtService: JwtService,
        private readonly gati: GatiService,
        private readonly aag: AagService
    ) {}

    private getTokenKey(token: string): string {
        return `${this.TOKEN_PREFIX}${token}`;
    }

    private getUserKey(userid: string): string {
        return `${this.USER_PREFIX}${userid}`;
    }

    async cacheToken(token: string, userid: string): Promise<void> {
        try {
            const tokenKey = this.getTokenKey(token);
            const userKey = this.getUserKey(userid);

            // Store token -> userid mapping
            await this.gati.put(tokenKey, { value: userid }, { ttl: this.TOKEN_EXPIRY });

            // Store userid -> token mapping
            await this.gati.put(userKey, { value: token }, { ttl: this.TOKEN_EXPIRY });

            this.aag.debug(`Token cached for user: ${userid}`);
        } catch (error) {
            this.aag.error(`Error caching token: ${error.message}`, error.stack);
            throw error;
        }
    }

    async getTokenUser(token: string): Promise<string | null> {
        try {
            const tokenKey = this.getTokenKey(token);
            const cachedUser = await this.gati.get(tokenKey);
            return typeof cachedUser?.value === 'string' ? cachedUser.value : null;
        } catch (error) {
            this.aag.error(`Error getting token user: ${error.message}`, error.stack);
            return null;
        }
    }

    async getUserToken(userid: string): Promise<string | null> {
        try {
            const userKey = this.getUserKey(userid);
            const cachedToken = await this.gati.get(userKey);
            return typeof cachedToken?.value === 'string' ? cachedToken.value : null;
        } catch (error) {
            this.aag.error(`Error getting user token: ${error.message}`, error.stack);
            return null;
        }
    }

    async invalidateToken(token: string): Promise<void> {
        try {
            const tokenKey = this.getTokenKey(token);
            const userid = await this.getTokenUser(token);

            if (userid) {
                const userKey = this.getUserKey(userid);
                await Promise.all([
                    this.gati.remove(tokenKey),
                    this.gati.remove(userKey)
                ]);
                this.aag.debug(`Token invalidated for user: ${userid}`);
            }
        } catch (error) {
            this.aag.error(`Error invalidating token: ${error.message}`, error.stack);
            throw error;
        }
    }

    async invalidateUserToken(userid: string): Promise<void> {
        try {
            const userKey = this.getUserKey(userid);
            const cachedToken = await this.gati.get(userKey);

            if (cachedToken?.value && typeof cachedToken.value === 'string') {
                const tokenKey = this.getTokenKey(cachedToken.value);
                await Promise.all([
                    this.gati.remove(tokenKey),
                    this.gati.remove(userKey)
                ]);
                this.aag.debug(`All tokens invalidated for user: ${userid}`);
            }
        } catch (error) {
            this.aag.error(`Error invalidating user tokens: ${error.message}`, error.stack);
            throw error;
        }
    }

    async isTokenBlacklisted(token: string): Promise<boolean> {
        try {
            const tokenKey = this.getTokenKey(token);
            const cachedUser = await this.gati.get(tokenKey);
            return !cachedUser?.value || typeof cachedUser.value !== 'string';
        } catch (error) {
            this.aag.error(`Error checking token blacklist: ${error.message}`, error.stack);
            return true; // If there's an error, consider the token as blacklisted for safety
        }
    }
}