if (process.env.NODE_ENV !== "test")
    require("server-only");
import crypto from "node:crypto";
import getPool from "@/lib/server/db";
import { apiError } from "@/lib/server/errors";
import type { Group } from "@/lib/shared/types";
import { requireGroupAdmin, requireGroupOwner } from "@/lib/server/group-access";
import { recordGroupAudit } from "@/lib/server/group-audit";

function createInviteCode() {
    return crypto.randomBytes(4).toString("hex").toUpperCase();
}

type GroupRow = {
    id: number;
    name: string;
    role: "MEMBER" | "GROUP_ADMIN" | "GROUP_OWNER";
};

export async function listGroups(userId: number): Promise<Group[]> {
    const pool = getPool();
    const rows = (await pool.query<GroupRow>(
        `select g.id, g.name, gm.role
     from group_members gm
     join groups g on g.id = gm.group_id
     where gm.user_id = $1
     order by g.created_at desc`,
        [userId]
    )).rows;

    return rows.map((row: GroupRow) => ({ id: Number(row.id), name: row.name, role: row.role }));
}

export async function getActiveGroupId(userId: number): Promise<number | null> {
    const pool = getPool();
    const { rows } = await pool.query(
        "select data->>'activeGroupId' as active_group_id from user_settings where user_id=$1",
        [userId]
    );
    const value = rows[0]?.active_group_id;
    if (!value) return null;
    const id = Number(value);
    return Number.isFinite(id) ? id : null;
}

export async function setActiveGroupId(userId: number, groupId: number) {
    const pool = getPool();
    await pool.query(
        `insert into user_settings(user_id, data)
     values($1, jsonb_build_object('activeGroupId', $2::int))
     on conflict (user_id) do update
     set data = user_settings.data || jsonb_build_object('activeGroupId', $2::int),
        updated_at = now()`,
        [userId, groupId]
    );
}

export async function setActiveGroupForUser(userId: number, groupId: number) {
    const pool = getPool();
    const { rowCount } = await pool.query(
        "select 1 from group_members where group_id=$1 and user_id=$2",
        [groupId, userId]
    );
    if (!rowCount) apiError("FORBIDDEN", { userId, groupId });
    await setActiveGroupId(userId, groupId);
}

export async function createGroup(userId: number, name: string) {
    const pool = getPool();
    const inviteCode = createInviteCode();
    const { rows } = await pool.query(
        "insert into groups(name, invite_code, created_by) values($1,$2,$3) returning id, name, invite_code",
        [name, inviteCode, userId]
    );
    const group = rows[0];
    await pool.query(
        "insert into group_members(group_id, user_id, role) values($1,$2,'GROUP_OWNER')",
        [group.id, userId]
    );
    await pool.query(
        "insert into group_settings(group_id, allow_member_tag_manage, join_policy) values($1,false,'NOT_ACCEPTING') on conflict (group_id) do nothing",
        [group.id]
    );
    return { id: group.id, name: group.name, inviteCode: group.invite_code } as { id: number; name: string; inviteCode: string };
}

export async function renameGroup(input: { userId: number; groupId: number; name: string; requestId: string; ip?: string | null; userAgent?: string | null }) {
    const role = await requireGroupAdmin(input.userId, input.groupId);
    const pool = getPool();
    const { rows } = await pool.query(
        "update groups set name=$2 where id=$1 returning name",
        [input.groupId, input.name]
    );
    if (!rows[0]) apiError("NOT_FOUND", { groupId: input.groupId });
    await recordGroupAudit({
        groupId: input.groupId,
        actorUserId: input.userId,
        actorRole: role,
        eventType: "GROUP_RENAMED",
        requestId: input.requestId,
        ip: input.ip,
        userAgent: input.userAgent,
        metadata: { name: input.name }
    });
}

export async function deleteGroup(input: { userId: number; groupId: number; requestId: string; ip?: string | null; userAgent?: string | null }) {
    await requireGroupOwner(input.userId, input.groupId);
    const pool = getPool();
    await pool.query(
        "delete from groups where id=$1",
        [input.groupId]
    );
    await recordGroupAudit({
        groupId: input.groupId,
        actorUserId: input.userId,
        actorRole: "GROUP_OWNER",
        eventType: "GROUP_DELETED",
        requestId: input.requestId,
        ip: input.ip,
        userAgent: input.userAgent
    });
}

export async function joinGroup(userId: number, inviteCode: string) {
    const pool = getPool();
    const { rows } = await pool.query(
        "select id, name from groups where invite_code=$1",
        [inviteCode]
    );
    const group = rows[0];
    if (!group)
        apiError("INVALID_INVITE", { inviteCode });

    const existing = await pool.query(
        "select 1 from group_members where group_id=$1 and user_id=$2",
        [group.id, userId]
    );
    if (existing.rowCount)
        return { id: group.id, name: group.name } as { id: number; name: string };

    const settings = await pool.query(
        "select join_policy from group_settings where group_id=$1",
        [group.id]
    );
    const joinPolicy = String(settings.rows[0]?.join_policy || "NOT_ACCEPTING") as "NOT_ACCEPTING" | "AUTO_ACCEPT" | "APPROVAL_REQUIRED";

    if (joinPolicy === "NOT_ACCEPTING")
        apiError("JOIN_NOT_ACCEPTING", { groupId: group.id, userId });

    if (joinPolicy === "AUTO_ACCEPT") {
        await pool.query(
            "insert into group_members(group_id, user_id, role) values($1,$2,'MEMBER')",
            [group.id, userId]
        );
        return { id: group.id, name: group.name } as { id: number; name: string };
    }

    await pool.query(
        `insert into group_join_requests(group_id, user_id, status)
         values($1,$2,'PENDING')
         on conflict (group_id, user_id) where status='PENDING'
         do update set updated_at=now()`,
        [group.id, userId]
    );
    apiError("JOIN_PENDING", { groupId: group.id, userId });
}

export async function requireActiveGroup(userId: number): Promise<number> {
    const activeGroupId = await getActiveGroupId(userId);
    if (!activeGroupId) apiError("NO_ACTIVE_GROUP", { userId });
    const groups = await listGroups(userId);
    const isMember = groups.some(group => Number(group.id) === activeGroupId);
    if (!isMember) apiError("FORBIDDEN", { userId, groupId: activeGroupId });
    return activeGroupId;
}