import { NextRequest, NextResponse } from "next/server";
import type { SupabaseClient } from "@supabase/supabase-js";
import { z } from "zod";
import type { Database } from "../shared/database";
import {
  commentInput,
  communityReportInput,
  communityReviewInput,
  reactionInput,
} from "../shared/community";
import { canReviewMaps } from "../shared/permissions";
import { browserAccount } from "./request-security";
import { ServiceError, checkServiceError } from "./service-error";

type Dependencies = {
  db: SupabaseClient<Database>;
  getUser: () => Promise<{ id: string } | null>;
  getProfile: (id: string) => Promise<{ id: string; role: string }>;
  jsonBody: (request: NextRequest) => Promise<unknown>;
  limit: (key: string, count: number, seconds: number) => Promise<void>;
};
const id = (value: string) => z.string().uuid().parse(value);
const cursorInput = z.tuple([
  z.string().datetime({ offset: true }),
  z.string().uuid(),
]);
const cursorFor = (row: { created_at: string; id: string }) =>
  `${row.created_at}|${row.id}`;
function cursorFilter(request: NextRequest, direction: "lt" | "gt") {
  const value = request.nextUrl.searchParams.get("cursor");
  if (!value) return null;
  const [created, rowId] = cursorInput.parse(value.split("|"));
  return `created_at.${direction}.${created},and(created_at.eq.${created},id.${direction}.${rowId})`;
}
function rows<T>(result: {
  data: T;
  error: { message: string; code?: string } | null;
}): NonNullable<T> {
  checkServiceError(result.error);
  if (result.data == null) throw new ServiceError("Content not found", 404);
  return result.data;
}
const respond = (body: unknown, status = 200) =>
  NextResponse.json(body, { status, headers: { "Cache-Control": "no-store" } });

export async function communityApi(
  request: NextRequest,
  path: string[],
  { db, getUser, getProfile, jsonBody, limit }: Dependencies,
) {
  const method = request.method;
  async function account(staff = false) {
    const current = await browserAccount(request, getUser);
    const profile = await getProfile(current.id);
    if (staff && !canReviewMaps(profile.role))
      throw new ServiceError("Moderator permission required", 403);
    return profile;
  }
  async function published(datasetId: string) {
    rows(
      await db
        .from("datasets")
        .select("id")
        .eq("id", datasetId)
        .eq("state", "published")
        .maybeSingle(),
    );
  }
  if (
    path[0] === "maps" &&
    path[2] === "community" &&
    path.length === 3 &&
    method === "GET"
  ) {
    const datasetId = id(path[1]);
    await published(datasetId);
    const current = await getUser();
    const profile = current ? await getProfile(current.id) : null;
    const filter = cursorFilter(request, "lt");
    let commentQuery = db
      .from("map_comments")
      .select("id,body,created_at,author_id")
      .eq("dataset_id", datasetId)
      .is("removed_at", null)
      .order("created_at", { ascending: false })
      .order("id", { ascending: false })
      .limit(31);
    if (filter) commentQuery = commentQuery.or(filter);
    const [summary, comments, reaction] = await Promise.all([
      db.rpc("map_reaction_summary", { p_dataset: datasetId }),
      commentQuery,
      current
        ? db
            .from("map_reactions")
            .select("value")
            .eq("dataset_id", datasetId)
            .eq("user_id", current.id)
            .maybeSingle()
        : Promise.resolve({ data: null, error: null }),
    ]);
    const items = rows(comments);
    const authors = [
      ...new Set(items.flatMap((c) => (c.author_id ? [c.author_id] : []))),
    ];
    const profiles = authors.length
      ? rows(
          await db
            .from("profiles")
            .select(
              "id,display_name,role,name_glow,glow_color,bug_finder,custom_prefix,custom_prefix_icon",
            )
            .in("id", authors),
        )
      : [];
    const byId = new Map(profiles.map((p) => [p.id, p]));
    checkServiceError(reaction.error);
    const totals = rows(summary)[0];
    return respond({
      likes: Number(totals?.likes ?? 0),
      dislikes: Number(totals?.dislikes ?? 0),
      reaction: reaction.data?.value ?? 0,
      viewer: profile
        ? { id: profile.id, canModerate: canReviewMaps(profile.role) }
        : null,
      comments: items.slice(0, 30).map((c) => ({
        ...c,
        author: byId.get(c.author_id ?? "")?.display_name ?? "Deleted player",
        appearance: byId.get(c.author_id ?? ""),
      })),
      nextCursor: items.length > 30 ? cursorFor(items[29]) : null,
    });
  }
  if (
    path[0] === "maps" &&
    path.length === 3 &&
    ["reaction", "comments"].includes(path[2]) &&
    method === "POST"
  ) {
    const current = await account();
    const datasetId = id(path[1]);
    await published(datasetId);
    if (path[2] === "reaction") {
      const body = reactionInput.parse(await jsonBody(request));
      await limit("community:reaction:" + current.id, 120, 60);
      const result =
        body.value === 0
          ? await db
              .from("map_reactions")
              .delete()
              .eq("dataset_id", datasetId)
              .eq("user_id", current.id)
          : await db.from("map_reactions").upsert(
              {
                dataset_id: datasetId,
                user_id: current.id,
                value: body.value,
              },
              { onConflict: "dataset_id,user_id" },
            );
      checkServiceError(result.error);
      return respond({ ok: true });
    }
    const body = commentInput.parse(await jsonBody(request));
    await limit("community:comment:" + current.id, 10, 600);
    rows(
      await db
        .from("map_comments")
        .insert({
          dataset_id: datasetId,
          author_id: current.id,
          body: body.body,
        })
        .select("id")
        .single(),
    );
    return respond({ ok: true }, 201);
  }
  if (
    path[0] === "community" &&
    path[1] === "comments" &&
    path.length === 3 &&
    method === "DELETE"
  ) {
    const reviewer = await account(true);
    const result = await db
      .from("map_comments")
      .update({ removed_at: new Date().toISOString(), removed_by: reviewer.id })
      .eq("id", id(path[2]))
      .is("removed_at", null)
      .select("id")
      .maybeSingle();
    rows(result);
    return respond({ ok: true });
  }
  if (path.join("/") === "community/reports" && method === "POST") {
    const current = await account();
    const body = communityReportInput.parse(await jsonBody(request));
    await limit("community:report:" + current.id, 10, 3600);
    if (body.target === "comment") {
      const comment = rows(
        await db
          .from("map_comments")
          .select("dataset_id")
          .eq("id", body.targetId)
          .is("removed_at", null)
          .maybeSingle(),
      );
      await published(comment.dataset_id);
    } else {
      if (body.targetId === current.id)
        throw new ServiceError("You cannot report your own account", 400);
      rows(
        await db
          .from("profiles")
          .select("id")
          .eq("id", body.targetId)
          .maybeSingle(),
      );
    }
    const result = await db.from("community_reports").insert({
      reporter_id: current.id,
      target: body.target,
      comment_id: body.target === "comment" ? body.targetId : null,
      account_id: body.target === "account" ? body.targetId : null,
      category: body.category,
      reason: body.reason,
    });
    if (result.error?.code === "23505")
      throw new ServiceError(
        "You already have an open report for this content",
        409,
      );
    checkServiceError(result.error);
    return respond({ ok: true }, 201);
  }
  if (path[0] === "moderation" && path[1] === "community-reports") {
    const reviewer = await account(true);
    if (method === "GET" && path.length === 2) {
      const filter = cursorFilter(request, "gt");
      let query = db
        .from("community_reports")
        .select("*")
        .eq("state", "open")
        .order("created_at")
        .order("id")
        .limit(51);
      if (filter) query = query.or(filter);
      const reports = rows(await query);
      const commentIds = reports.flatMap((r) =>
        r.comment_id ? [r.comment_id] : [],
      );
      const accountIds = reports.flatMap((r) =>
        r.account_id ? [r.account_id] : [],
      );
      const [comments, accounts] = await Promise.all([
        commentIds.length
          ? db.from("map_comments").select("*").in("id", commentIds)
          : Promise.resolve({ data: [], error: null }),
        accountIds.length
          ? db.from("profiles").select("id,display_name").in("id", accountIds)
          : Promise.resolve({ data: [], error: null }),
      ]);
      const byComment = new Map(rows(comments).map((c) => [c.id, c]));
      const byAccount = new Map(
        rows(accounts).map((a) => [a.id, a.display_name]),
      );
      return respond({
        reports: reports.slice(0, 50).map((r) => ({
          ...r,
          comment: byComment.get(r.comment_id ?? "") ?? null,
          accountName: byAccount.get(r.account_id ?? "") ?? null,
        })),
        nextCursor: reports.length > 50 ? cursorFor(reports[49]) : null,
      });
    }
    if (method === "PATCH" && path.length === 3) {
      const body = communityReviewInput.parse(await jsonBody(request));
      const result = await db
        .from("community_reports")
        .update({
          state: body.decision,
          reviewer_id: reviewer.id,
          reviewed_at: new Date().toISOString(),
          review_reason: body.reason,
        })
        .eq("id", id(path[2]))
        .eq("state", "open")
        .select("id")
        .maybeSingle();
      checkServiceError(result.error);
      if (!result.data)
        throw new ServiceError("Report already reviewed or not found", 409);
      return respond({ ok: true });
    }
  }
  return respond({ error: "Not found" }, 404);
}