import {
    admin,
    customSession,
    magicLink,
    multiSession,
    username,
} from "better-auth/plugins";
import { getUserController, UserController } from "../user/controller";
import { AuthController, getAuthController } from "./controller";
import { drizzleAdapter } from "better-auth/adapters/drizzle";
import { FlowExecCtx } from "@/core/flow.execution.context";
import { UserRoleMap } from "@domains/user/data";
import { getRedisInstance } from "@pkg/keystore";
import { APIError } from "better-auth/api";
import { settings } from "@core/settings";
import { betterAuth } from "better-auth";
import { logger } from "@pkg/logger";
import { db, schema } from "@pkg/db";
import { nanoid } from "nanoid";

// Constants
const EMAIL_EXPIRES_IN_MINS = 10;
const EMAIL_EXPIRES_IN_SECONDS = 60 * EMAIL_EXPIRES_IN_MINS;
const COOKIE_CACHE_MAX_AGE = 60 * 5;

// Helper to create flow context for better-auth callbacks
function createAuthFlowContext(contextLabel: string): FlowExecCtx {
    return {
        flowId: `auth:${contextLabel}:${nanoid(10)}`,
    };
}

// Singleton controller instances
let authControllerInstance: AuthController | null = null;
let userControllerInstance: UserController | null = null;

function getAuthControllerInstance(): AuthController {
    if (!authControllerInstance) {
        authControllerInstance = getAuthController();
    }
    return authControllerInstance;
}

function getUserControllerInstance(): UserController {
    if (!userControllerInstance) {
        userControllerInstance = getUserController();
    }
    return userControllerInstance;
}

export const auth = betterAuth({
    trustedOrigins: ["http://localhost:5173", settings.betterAuthUrl],
    advanced: { useSecureCookies: settings.nodeEnv === "production" },
    appName: settings.appName,
    emailAndPassword: {
        enabled: true,
        disableSignUp: true,
        requireEmailVerification: false,
    },
    plugins: [
        customSession(async ({ user, session }) => {
            session.id = session.token;
            return { user, session };
        }),
        username({
            minUsernameLength: 5,
            maxUsernameLength: 20,
            usernameValidator: async (username) => {
                const fctx = createAuthFlowContext("username-check");
                const uc = getUserControllerInstance();

                const result = await uc
                    .isUsernameAvailable(fctx, username)
                    .match(
                        (isAvailable) => ({ success: true, isAvailable }),
                        (error) => {
                            logger.error(
                                `[${fctx.flowId}] Failed to check username availability`,
                                error,
                            );
                            return { success: false, isAvailable: false };
                        },
                    );

                return result.isAvailable;
            },
        }),
        magicLink({
            expiresIn: EMAIL_EXPIRES_IN_SECONDS,
            rateLimit: { window: 60, max: 4 },
            sendMagicLink: async ({ email, token, url }, request) => {
                const fctx = createAuthFlowContext("magic-link");
                const ac = getAuthControllerInstance();

                const result = await ac
                    .sendMagicLink(fctx, email, token, url)
                    .match(
                        () => ({ success: true, error: undefined }),
                        (error) => ({ success: false, error }),
                    );

                if (!result.success || result?.error) {
                    logger.error(
                        `[${fctx.flowId}] Failed to send magic link`,
                        result.error,
                    );
                    throw new APIError("INTERNAL_SERVER_ERROR", {
                        message: result.error?.message,
                    });
                }
            },
        }),
        admin({
            defaultRole: UserRoleMap.admin,
            defaultBanReason:
                "Stop fanum taxing the server bub, losing aura points fr",
            defaultBanExpiresIn: 60 * 60 * 24,
        }),
        multiSession({ maximumSessions: 5 }),
    ],
    logger: {
        log: (level, message, metadata) => {
            logger.log(level, message, metadata);
        },
        level: settings.isDevelopment ? "debug" : "info",
    },
    database: drizzleAdapter(db, { provider: "pg", schema: { ...schema } }),
    secondaryStorage: {
        get: async (key) => {
            const redis = getRedisInstance();
            return await redis.get(key);
        },
        set: async (key, value, ttl) => {
            const redis = getRedisInstance();
            if (ttl) {
                await redis.setex(key, ttl, value);
            } else {
                await redis.set(key, value);
            }
        },
        delete: async (key) => {
            const redis = getRedisInstance();
            const out = await redis.del(key);
            if (!out && out !== 0) {
                return null;
            }
            return out.toString() as any;
        },
    },
    session: {
        modelName: "session",
        expiresIn: 60 * 60 * 24 * 7,
        updateAge: 60 * 60 * 24,
        cookieCache: {
            enabled: true,
            maxAge: COOKIE_CACHE_MAX_AGE,
        },
    },
    user: {
        changeEmail: {
            enabled: true,
            sendChangeEmailVerification: async (
                { user, newEmail, url, token },
                request,
            ) => {
                const fctx = createAuthFlowContext("email-change");
                const ac = getAuthControllerInstance();

                const result = await ac
                    .sendEmailChangeVerificationEmail(
                        fctx,
                        newEmail,
                        token,
                        url,
                    )
                    .match(
                        () => ({ success: true, error: undefined }),
                        (error) => ({ success: false, error }),
                    );

                if (!result.success || result?.error) {
                    logger.error(
                        `[${fctx.flowId}] Failed to send email change verification`,
                        result.error,
                    );
                    throw new APIError("INTERNAL_SERVER_ERROR", {
                        message: result.error?.message,
                    });
                }
            },
        },
        modelName: "user",
        additionalFields: {
            onboardingDone: {
                type: "boolean",
                defaultValue: false,
                required: false,
            },
            last2FAVerifiedAt: { type: "date", required: false },
            parentId: { required: false, type: "string" },
        },
    },
});

// - - -