import { Request, Response, NextFunction } from "express";
import { z } from "zod";
import { db } from "@server/db";
import response from "@server/lib/response";
import HttpCode from "@server/types/HttpCode";
import createHttpError from "http-errors";
import logger from "@server/logger";
import { fromError } from "zod-validation-error";
import {
    idp,
    idpOidcConfig,
    idpOrg,
    Role,
    roles,
    userOrgs,
    users
} from "@server/db/schemas";
import { and, eq, inArray } from "drizzle-orm";
import * as arctic from "arctic";
import { generateOidcRedirectUrl } from "@server/lib/idp/generateRedirectUrl";
import jmespath from "jmespath";
import jsonwebtoken from "jsonwebtoken";
import config from "@server/lib/config";
import { UserType } from "@server/types/UserTypes";
import {
    createSession,
    generateId,
    generateSessionToken,
    serializeSessionCookie
} from "@server/auth/sessions/app";

const paramsSchema = z
    .object({
        idpId: z.coerce.number()
    })
    .strict();

const bodySchema = z.object({
    code: z.string().nonempty(),
    state: z.string().nonempty(),
    storedState: z.string().nonempty()
});

export type ValidateOidcUrlCallbackResponse = {
    redirectUrl: string;
};

export async function validateOidcCallback(
    req: Request,
    res: Response,
    next: NextFunction
): Promise<any> {
    try {
        const parsedParams = paramsSchema.safeParse(req.params);
        if (!parsedParams.success) {
            return next(
                createHttpError(
                    HttpCode.BAD_REQUEST,
                    fromError(parsedParams.error).toString()
                )
            );
        }

        const { idpId } = parsedParams.data;

        const parsedBody = bodySchema.safeParse(req.body);
        if (!parsedBody.success) {
            return next(
                createHttpError(
                    HttpCode.BAD_REQUEST,
                    fromError(parsedBody.error).toString()
                )
            );
        }

        const { storedState, code, state: expectedState } = parsedBody.data;

        const [existingIdp] = await db
            .select()
            .from(idp)
            .innerJoin(idpOidcConfig, eq(idpOidcConfig.idpId, idp.idpId))
            .where(and(eq(idp.type, "oidc"), eq(idp.idpId, idpId)));

        if (!existingIdp) {
            return next(
                createHttpError(
                    HttpCode.BAD_REQUEST,
                    "IdP not found for the organization"
                )
            );
        }

        const redirectUrl = generateOidcRedirectUrl(existingIdp.idp.idpId);
        const client = new arctic.OAuth2Client(
            existingIdp.idpOidcConfig.clientId,
            existingIdp.idpOidcConfig.clientSecret,
            redirectUrl
        );

        const statePayload = jsonwebtoken.verify(
            storedState,
            config.getRawConfig().server.secret,
            function (err, decoded) {
                if (err) {
                    logger.error("Error verifying state JWT", { err });
                    return next(
                        createHttpError(
                            HttpCode.BAD_REQUEST,
                            "Invalid state JWT"
                        )
                    );
                }
                return decoded;
            }
        );

        const stateObj = z
            .object({
                redirectUrl: z.string(),
                state: z.string(),
                codeVerifier: z.string()
            })
            .safeParse(statePayload);

        if (!stateObj.success) {
            logger.error("Error parsing state JWT");
            return next(
                createHttpError(
                    HttpCode.BAD_REQUEST,
                    fromError(stateObj.error).toString()
                )
            );
        }

        const {
            codeVerifier,
            state,
            redirectUrl: postAuthRedirectUrl
        } = stateObj.data;

        if (state !== expectedState) {
            logger.error("State mismatch", { expectedState, state });
            return next(
                createHttpError(HttpCode.BAD_REQUEST, "State mismatch")
            );
        }

        const tokens = await client.validateAuthorizationCode(
            existingIdp.idpOidcConfig.tokenUrl,
            code,
            codeVerifier
        );

        const idToken = tokens.idToken();
        const claims = arctic.decodeIdToken(idToken);

        const userIdentifier = jmespath.search(
            claims,
            existingIdp.idpOidcConfig.identifierPath
        );

        if (!userIdentifier) {
            return next(
                createHttpError(
                    HttpCode.BAD_REQUEST,
                    "User identifier not found in the ID token"
                )
            );
        }

        logger.debug("User identifier", { userIdentifier });

        let email = null;
        let name = null;
        try {
            if (existingIdp.idpOidcConfig.emailPath) {
                email = jmespath.search(
                    claims,
                    existingIdp.idpOidcConfig.emailPath
                );
            }

            if (existingIdp.idpOidcConfig.namePath) {
                name = jmespath.search(
                    claims,
                    existingIdp.idpOidcConfig.namePath || ""
                );
            }
        } catch (error) {}

        logger.debug("User email", { email });
        logger.debug("User name", { name });

        const [existingUser] = await db
            .select()
            .from(users)
            .where(
                and(
                    eq(users.username, userIdentifier),
                    eq(users.idpId, existingIdp.idp.idpId)
                )
            );

        const idpOrgs = await db
            .select()
            .from(idpOrg)
            .where(eq(idpOrg.idpId, existingIdp.idp.idpId));

        let userOrgInfo: { orgId: string; roleId: number }[] = [];
        for (const idpOrg of idpOrgs) {
            let roleId: number | undefined = undefined;

            if (idpOrg.orgMapping) {
                const orgId = jmespath.search(claims, idpOrg.orgMapping);
                if (!orgId) {
                    continue;
                }
            }

            if (idpOrg.roleMapping) {
                const roleName = jmespath.search(claims, idpOrg.roleMapping);

                if (!roleName) {
                    logger.error("Role name not found in the ID token", {
                        roleName
                    });
                    continue;
                }

                const [roleRes] = await db
                    .select()
                    .from(roles)
                    .where(
                        and(
                            eq(roles.orgId, idpOrg.orgId),
                            eq(roles.name, roleName)
                        )
                    );

                if (!roleRes) {
                    logger.error("Role not found", {
                        orgId: idpOrg.orgId,
                        roleName
                    });
                    continue;
                }

                roleId = roleRes.roleId;

                userOrgInfo.push({
                    orgId: idpOrg.orgId,
                    roleId
                });
            }
        }

        logger.debug("User org info", { userOrgInfo });

        let existingUserId = existingUser?.userId;

        // sync the user with the orgs and roles
        await db.transaction(async (trx) => {
            let userId = existingUser?.userId;

            // create user if not exists
            if (!existingUser) {
                userId = generateId(15);

                await trx.insert(users).values({
                    userId,
                    username: userIdentifier,
                    email: email || null,
                    name: name || null,
                    type: UserType.OIDC,
                    idpId: existingIdp.idp.idpId,
                    emailVerified: true, // OIDC users are always verified
                    dateCreated: new Date().toISOString()
                });
            } else {
                // set the name and email
                await trx
                    .update(users)
                    .set({
                        username: userIdentifier,
                        email: email || null,
                        name: name || null
                    })
                    .where(eq(users.userId, userId));
            }

            existingUserId = userId;

            // get all current user orgs
            const currentUserOrgs = await trx
                .select()
                .from(userOrgs)
                .where(eq(userOrgs.userId, userId));

            // Delete orgs that are no longer valid
            const orgsToDelete = currentUserOrgs.filter(
                (currentOrg) =>
                    !userOrgInfo.some(
                        (newOrg) => newOrg.orgId === currentOrg.orgId
                    )
            );

            if (orgsToDelete.length > 0) {
                await trx.delete(userOrgs).where(
                    and(
                        eq(userOrgs.userId, userId),
                        inArray(
                            userOrgs.orgId,
                            orgsToDelete.map((org) => org.orgId)
                        )
                    )
                );
            }

            // Update roles for existing orgs where the role has changed
            const orgsToUpdate = currentUserOrgs.filter((currentOrg) => {
                const newOrg = userOrgInfo.find(
                    (newOrg) => newOrg.orgId === currentOrg.orgId
                );
                return newOrg && newOrg.roleId !== currentOrg.roleId;
            });

            if (orgsToUpdate.length > 0) {
                for (const org of orgsToUpdate) {
                    const newRole = userOrgInfo.find(
                        (newOrg) => newOrg.orgId === org.orgId
                    );
                    if (newRole) {
                        await trx
                            .update(userOrgs)
                            .set({ roleId: newRole.roleId })
                            .where(
                                and(
                                    eq(userOrgs.userId, userId),
                                    eq(userOrgs.orgId, org.orgId)
                                )
                            );
                    }
                }
            }

            // Add new orgs that don't exist yet
            const orgsToAdd = userOrgInfo.filter(
                (newOrg) =>
                    !currentUserOrgs.some(
                        (currentOrg) => currentOrg.orgId === newOrg.orgId
                    )
            );

            if (orgsToAdd.length > 0) {
                await trx.insert(userOrgs).values(
                    orgsToAdd.map((org) => ({
                        userId,
                        orgId: org.orgId,
                        roleId: org.roleId,
                        dateCreated: new Date().toISOString()
                    }))
                );
            }
        });

        const token = generateSessionToken();
        const sess = await createSession(token, existingUserId);
        const isSecure = req.protocol === "https";
        const cookie = serializeSessionCookie(
            token,
            isSecure,
            new Date(sess.expiresAt)
        );

        res.appendHeader("Set-Cookie", cookie);

        return response<ValidateOidcUrlCallbackResponse>(res, {
            data: {
                redirectUrl: postAuthRedirectUrl
            },
            success: true,
            error: false,
            message: "OIDC callback validated successfully",
            status: HttpCode.CREATED
        });
    } catch (error) {
        logger.error(error);
        return next(
            createHttpError(HttpCode.INTERNAL_SERVER_ERROR, "An error occurred")
        );
    }
}