import "server-only";
import { createClient } from "@supabase/supabase-js";
import { randomUUID } from "node:crypto";
import sharp from "sharp";
import { NextRequest, NextResponse } from "next/server";
import {
  admin,
  authClient,
  required,
  user,
  rawUser,
  accountState,
} from "./supabase";
import { accountProfile } from "./profile";
import { browserAccount } from "./request-security";
import { ServiceError } from "./service-error";
import {
  authActionSchema,
  authDestination,
  passwordUpdateSchema,
  profileUpdateSchema,
  initialPasswordSchema,
} from "@/shared/account";
import { createHash } from "node:crypto";
import { recoveryCookie, verifyRecoveryGrant } from "./password-recovery";
import { requestOrigin } from "./request-origin";
import { issueInitialPassword } from "@/shared/initial-password";
import {
  profileAvatarBucket,
  profileAvatarMaxBytes,
} from "@/shared/profile-appearance";

type Context = {
  jsonBody: (r: NextRequest) => Promise<unknown>;
  limit: (key: string, count: number, seconds: number) => Promise<void>;
};
const json = (body: unknown, status = 200) =>
  NextResponse.json(body, { status, headers: { "Cache-Control": "no-store" } });
const avatarRequestLimit = profileAvatarMaxBytes + 64 * 1024;

async function avatarFile(request: NextRequest): Promise<File> {
  const contentType = request.headers.get("content-type") ?? "";
  if (!/^multipart\/form-data\s*;.*\bboundary=/i.test(contentType))
    throw new ServiceError("Choose a valid profile photo", 400);
  const contentLength = request.headers.get("content-length");
  if (
    contentLength &&
    /^\d+$/.test(contentLength) &&
    Number(contentLength) > avatarRequestLimit
  )
    throw new ServiceError("Image must be 5 MB or smaller", 413);

  const reader = request.body?.getReader();
  if (!reader) throw new ServiceError("Choose a profile photo", 400);
  const chunks: Uint8Array[] = [];
  let size = 0;
  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    size += value.byteLength;
    if (size > avatarRequestLimit) {
      try {
        await reader.cancel();
      } catch {
        // The request is already being rejected; cancellation is best effort.
      }
      throw new ServiceError("Image must be 5 MB or smaller", 413);
    }
    chunks.push(value);
  }

  let form: FormData;
  try {
    const boundedRequest = new Request(request.url, {
      method: "POST",
      headers: { "content-type": contentType },
      body: Buffer.concat(chunks, size),
    });
    form = await boundedRequest.formData();
  } catch {
    throw new ServiceError("Choose a valid profile photo", 400);
  }
  const entries = [...form.entries()];
  if (entries.length !== 1)
    throw new ServiceError("Choose a valid profile photo", 400);
  const entry = entries[0]!;
  if (
    entry[0] !== "photo" ||
    typeof entry[1] === "string" ||
    !(entry[1] instanceof File)
  )
    throw new ServiceError("Choose a valid profile photo", 400);
  const file = entry[1];
  if (!file.size || file.size > profileAvatarMaxBytes)
    throw new ServiceError("Image must be 5 MB or smaller", 413);
  return file;
}

async function normalizedAvatar(file: File) {
  try {
    const image = sharp(Buffer.from(await file.arrayBuffer()), {
      limitInputPixels: 24_000_000,
      failOn: "error",
      animated: false,
    });
    const metadata = await image.metadata();
    if (
      !["jpeg", "png", "webp"].includes(metadata.format ?? "") ||
      (metadata.pages ?? 1) !== 1
    )
      throw new ServiceError("Choose a JPG, PNG or WebP image", 400);
    const output = await image
      .rotate()
      .resize({
        width: 512,
        height: 512,
        fit: "inside",
        withoutEnlargement: true,
      })
      .webp({ quality: 85 })
      .toBuffer();
    if (output.byteLength > profileAvatarMaxBytes)
      throw new ServiceError("Image must be 5 MB or smaller", 413);
    return output;
  } catch (error) {
    if (error instanceof ServiceError) throw error;
    throw new ServiceError("Choose a valid JPG, PNG or WebP image", 400);
  }
}

export async function accountApi(
  request: NextRequest,
  path: string[],
  context: Context,
) {
  if (
    path[0] === "auth" &&
    path[1] === "logout" &&
    path.length === 2 &&
    request.method === "POST"
  ) {
    const client = await authClient();
    const { error } = await client.auth.signOut({ scope: "local" });
    if (error) throw new Error("Could not sign out. Please try again.");
    const response = json({ ok: true });
    for (const name of ["mg_guest", "mg_multiplayer"])
      response.cookies.set(name, "", {
        path: "/",
        maxAge: 0,
        httpOnly: true,
        sameSite: "lax",
      });
    return response;
  }
  if (path[0] === "profile" && path[1] === "avatar" && path.length === 2) {
    if (request.method !== "POST")
      return json({ error: "Method not allowed" }, 405);
    const account = await browserAccount(request, user);
    await context.limit(`profile:avatar:${account.id}`, 10, 3600);
    const file = await avatarFile(request);
    const image = await normalizedAvatar(file);
    const profileBefore = await accountProfile(account);
    const avatarPath = `${account.id}/${randomUUID()}.webp`;
    const storage = admin().storage.from(profileAvatarBucket);
    const upload = await storage.upload(avatarPath, image, {
      cacheControl: "31536000",
      contentType: "image/webp",
      upsert: false,
    });
    if (upload.error)
      throw new ServiceError(
        "Profile photo upload failed. Please try again.",
        503,
      );

    const profile = await (async () => {
      try {
        return required(
          await admin()
            .from("profiles")
            .update({ avatar_path: avatarPath })
            .eq("id", account.id)
            .select(
              "id,display_name,bio,avatar_path,profile_effect,role,name_glow,glow_color,bug_finder,custom_prefix,custom_prefix_icon",
            )
            .single(),
        );
      } catch (error) {
        await storage.remove([avatarPath]).catch(() => {});
        throw error;
      }
    })();
    if (
      profileBefore.avatar_path &&
      profileBefore.avatar_path.startsWith(`${account.id}/`) &&
      profileBefore.avatar_path.split("/").length === 2
    )
      await storage.remove([profileBefore.avatar_path]).catch(() => {});
    return json({ profile });
  }
  if (
    path[0] === "auth" &&
    path[1] === "initial-password" &&
    path.length === 2
  ) {
    const account = await rawUser();
    if (!account?.email || !account.email_confirmed_at)
      return json({ error: "Log in to manage your account" }, 401);
    if (request.method === "GET") {
      return json({
        needed: required(
          await admin().rpc("legacy_password_needed", { p_user: account.id }),
        ),
      });
    }
    if (request.method !== "POST")
      return json({ error: "Method not allowed" }, 405);
    const body = initialPasswordSchema.parse(await context.jsonBody(request));
    await context.limit(`initial-password:${account.id}`, 3, 600);
    await issueInitialPassword(account.id, body.password, {
      claim: async (id) =>
        required(await admin().rpc("claim_legacy_password", { p_user: id })),
      update: async (id, password) => {
        const { error } = await admin().auth.admin.updateUserById(id, {
          password,
        });
        if (error)
          throw new Error(
            "Password setup could not be confirmed. Use password recovery before signing out.",
          );
      },
    });
    return json({ ok: true });
  }
  if (path[0] === "profile" && path.length === 1) {
    const account = await browserAccount(request, user);
    if (request.method === "GET")
      return json({
        profile: await accountProfile(account),
        email: account.email,
      });
    if (request.method === "PATCH") {
      const body = profileUpdateSchema.parse(await context.jsonBody(request));
      const current = await accountProfile(account);
      if (
        body.avatarPath !== undefined &&
        body.avatarPath !== null &&
        body.avatarPath !== current.avatar_path
      )
        return json(
          { error: "Upload a profile photo through the avatar form" },
          400,
        );
      if (body.glowColor !== undefined && !current.name_glow)
        return json(
          { error: "Earn a username glow before choosing its color" },
          403,
        );
      const profile = required(
        await admin()
          .from("profiles")
          .update({
            ...(body.displayName !== undefined
              ? { display_name: body.displayName }
              : {}),
            ...(body.glowColor !== undefined
              ? { glow_color: body.glowColor }
              : {}),
            ...(body.avatarPath !== undefined
              ? { avatar_path: body.avatarPath }
              : {}),
            ...(body.bio !== undefined ? { bio: body.bio } : {}),
          })
          .eq("id", account.id)
          .select(
            "id,display_name,bio,avatar_path,profile_effect,role,name_glow,glow_color,bug_finder,custom_prefix,custom_prefix_icon",
          )
          .single(),
      );
      if (
        body.avatarPath !== undefined &&
        body.avatarPath !== current.avatar_path
      ) {
        if (
          current.avatar_path?.startsWith(`${account.id}/`) &&
          current.avatar_path.split("/").length === 2
        )
          await admin()
            .storage.from(profileAvatarBucket)
            .remove([current.avatar_path]);
      }
      return json({ profile });
    }
    return json({ error: "Method not allowed" }, 405);
  }
  if (path[0] !== "auth" || request.method !== "POST" || path.length > 2)
    return json({ error: "Not found" }, 404);
  const client = await authClient();
  if (path.length === 1) {
    const body = authActionSchema.parse(await context.jsonBody(request));
    const identity = createHash("sha256")
      .update(body.email.toLowerCase())
      .digest("hex");
    await context.limit(
      `auth:${body.action}:${identity}`,
      body.action === "login" ? 15 : 5,
      600,
    );
    const origin = requestOrigin(request, process.env.MINEGEO_URL);
    const next = authDestination("next" in body ? body.next : null);
    const callback = new URL("/auth/callback", origin);
    callback.searchParams.set(
      "type",
      body.action === "recover" ? "recovery" : "signup",
    );
    callback.searchParams.set(
      "next",
      body.action === "recover"
        ? "/auth/reset-password"
        : next === "/auth/reset-password"
          ? "/dashboard"
          : next,
    );
    if (body.action === "login") {
      const { data, error } = await client.auth.signInWithPassword({
        email: body.email,
        password: body.password,
      });
      if (error)
        return json(
          {
            error:
              error.code === "email_not_confirmed"
                ? "Confirm your email address before logging in."
                : "Email or password is incorrect. Try again or reset your password.",
          },
          401,
        );
      return json({
        next:
          data.user && (await accountState(data.user.id)) !== "active"
            ? "/ban/appeal"
            : next,
      });
    }
    if (body.action === "signup") {
      const { data, error } = await client.auth.signUp({
        email: body.email,
        password: body.password,
        options: {
          data: { display_name: body.displayName },
          emailRedirectTo: callback.toString(),
        },
      });
      if (error) throw new Error(error.message);
      if (data.session && data.user) {
        await accountProfile(data.user);
        return json({ next });
      }
      return json({
        message:
          "Check your email to confirm your account. If you already have an account, log in or reset your password.",
      });
    }
    const { error } = await client.auth.resetPasswordForEmail(body.email, {
      redirectTo: callback.toString(),
    });
    if (
      error &&
      !["user_not_found", "signup_disabled"].includes(error.code ?? "")
    )
      throw new Error(error.message);
    return json({
      message:
        "If an account exists for this email, a password reset link is on its way. Check your inbox.",
    });
  }
  if (path[1] !== "password") return json({ error: "Not found" }, 404);
  const account = await rawUser();
  if (!account?.email)
    return json({ error: "Log in before changing your password" }, 401);
  const body = passwordUpdateSchema.parse(await context.jsonBody(request));
  await context.limit(`password:${account.id}`, 10, 600);
  const { data: claimData, error: claimError } = await client.auth.getClaims();
  const sessionId =
    typeof claimData?.claims.session_id === "string"
      ? claimData.claims.session_id
      : "";
  if (claimError || !sessionId)
    return json({ error: "Your session expired. Log in again." }, 401);
  if (body.currentPassword) {
    // Verify through Auth without replacing this browser's session.
    const verifier = createClient(
      process.env.NEXT_PUBLIC_SUPABASE_URL!,
      process.env.NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY!,
      { auth: { persistSession: false, autoRefreshToken: false } },
    );
    const { error } = await verifier.auth.signInWithPassword({
      email: account.email,
      password: body.currentPassword,
    });
    if (error)
      return json(
        {
          error:
            "Your current password is incorrect. Use an email reset link if you have not set a password yet.",
        },
        403,
      );
    await verifier.auth.signOut({ scope: "local" });
  } else if (
    !verifyRecoveryGrant(
      request.cookies.get(recoveryCookie)?.value,
      account.id,
      sessionId,
      process.env.SUPABASE_SECRET_KEY!,
    )
  ) {
    return json(
      {
        error:
          "Enter your current password or open a fresh password reset link from your email.",
      },
      403,
    );
  }
  const { error } = await client.auth.updateUser({
    password: body.password,
    ...(body.currentPassword ? { current_password: body.currentPassword } : {}),
    ...(body.nonce ? { nonce: body.nonce } : {}),
  });
  if (error)
    return json(
      {
        error: error.message,
        needsReauthentication: error.code === "reauthentication_needed",
      },
      400,
    );
  const { error: signOutError } = await client.auth.signOut({
    scope: "others",
  });
  const response = json({
    ok: true,
    message: signOutError
      ? "Password updated. Other sessions could not be signed out; please try signing out other devices again."
      : "Password updated. Other devices have been signed out.",
  });
  response.cookies.set(recoveryCookie, "", {
    httpOnly: true,
    sameSite: "lax",
    path: "/",
    maxAge: 0,
  });
  return response;
}