import { createServerFn } from "@tanstack/react-start";
import { z } from "zod";

import { toLocalDateTimeString } from "@/lib/datetime";

export interface Perfil {
  id: string;
  email: string;
  nome: string;
  aprovado: boolean;
  created_at: string;
}

export interface SessaoAtual {
  userId: string;
  nome: string;
  admin: boolean;
  perfil: Perfil;
}

interface PerfilRow {
  id: string;
  email: string;
  nome: string;
  aprovado: boolean;
  created_at: Date | string;
}

const loginSchema = z.object({
  nome: z.string().min(3),
  senha: z.string().min(6),
});

function toPerfil(row: PerfilRow): Perfil {
  return {
    id: row.id,
    email: row.email,
    nome: row.nome,
    aprovado: Boolean(row.aprovado),
    created_at: toLocalDateTimeString(row.created_at),
  };
}

async function getSessionUserId(): Promise<string | null> {
  const { getSessionUserId: getServerSessionUserId } = await import("@/lib/auth.server");
  return await getServerSessionUserId();
}

async function fetchSessionProfile(userId: string): Promise<SessaoAtual | null> {
  const [{ getPool, sql }] = await Promise.all([import("@/lib/db.server")]);
  const pool = await getPool();

  const result = await pool
    .request()
    .input("userId", sql.UniqueIdentifier, userId)
    .query<PerfilRow & { admin: boolean }>(`
      SELECT
        u.id,
        u.email,
        u.nome,
        u.aprovado,
        u.created_at,
        CAST(CASE
          WHEN EXISTS (
            SELECT 1
            FROM slalog.usuarios_papeis up
            WHERE up.user_id = u.id AND up.role = 'admin'
          ) THEN 1
          ELSE 0
        END AS bit) AS admin
      FROM slalog.usuarios u
      WHERE u.id = @userId AND u.ativo = 1
    `);

  const row = result.recordset[0];
  if (!row) return null;

  const perfil = toPerfil(row);
  return {
    userId: perfil.id,
    nome: perfil.nome,
    admin: Boolean(row.admin),
    perfil,
  };
}

async function requireSession(): Promise<SessaoAtual> {
  const userId = await getSessionUserId();
  if (!userId) throw new Error("Não autenticado");

  const sessao = await fetchSessionProfile(userId);
  if (!sessao) throw new Error("Sessão inválida");
  return sessao;
}

async function requireAdminSession(): Promise<SessaoAtual> {
  const sessao = await requireSession();
  if (!sessao.admin) throw new Error("Apenas administradores podem executar esta ação.");
  return sessao;
}

async function requireApprovedSession(): Promise<SessaoAtual> {
  const sessao = await requireSession();
  if (!sessao.perfil.aprovado) throw new Error("Usuário aguardando aprovação.");
  return sessao;
}

export function normalizarNome(nome: string): string {
  return nome
    .trim()
    .toLowerCase()
    .normalize("NFD")
    .replace(/[\u0300-\u036f]/g, "")
    .replace(/[^a-z0-9._-]/g, "");
}

export function emailDeNome(nome: string): string {
  return `${normalizarNome(nome)}@coleta.local`;
}

export const obterSessaoAtual = createServerFn({ method: "GET" }).handler(async () => {
  const userId = await getSessionUserId();
  if (!userId) return null;
  return await fetchSessionProfile(userId);
});

export const entrar = createServerFn({ method: "POST" })
  .validator(loginSchema)
  .handler(async ({ data }) => {
    const nome = normalizarNome(data.nome);
    const [{ getPool, sql }, bcrypt] = await Promise.all([
      import("@/lib/db.server"),
      import("bcryptjs"),
    ]);
    const pool = await getPool();

    const result = await pool
      .request()
      .input("nome", sql.NVarChar(150), nome)
      .query<(PerfilRow & { senha_hash: string; admin: boolean; ativo: boolean })>(`
        SELECT
          u.id,
          u.email,
          u.nome,
          u.aprovado,
          u.ativo,
          u.created_at,
          u.senha_hash,
          CAST(CASE
            WHEN EXISTS (
              SELECT 1
              FROM slalog.usuarios_papeis up
              WHERE up.user_id = u.id AND up.role = 'admin'
            ) THEN 1
            ELSE 0
          END AS bit) AS admin
        FROM slalog.usuarios u
        WHERE LOWER(u.nome) = LOWER(@nome)
      `);

    const row = result.recordset[0];
    if (!row || !row.ativo) throw new Error("Nome de usuário ou senha incorretos.");

    const ok = await bcrypt.compare(data.senha, row.senha_hash);
    if (!ok) throw new Error("Nome de usuário ou senha incorretos.");

    const { setSessionUserId } = await import("@/lib/auth.server");
    await setSessionUserId(row.id);

    const perfil = toPerfil(row);
    return {
      userId: row.id,
      nome: row.nome,
      admin: Boolean(row.admin),
      perfil,
    } satisfies SessaoAtual;
  });

export const criarConta = createServerFn({ method: "POST" })
  .validator(loginSchema)
  .handler(async ({ data }) => {
    const nome = normalizarNome(data.nome);
    const email = emailDeNome(nome);
    const [{ getPool, sql }, bcrypt] = await Promise.all([
      import("@/lib/db.server"),
      import("bcryptjs"),
    ]);
    const pool = await getPool();

    const existente = await pool
      .request()
      .input("nome", sql.NVarChar(150), nome)
      .query<{ id: string }>(`
        SELECT TOP 1 id
        FROM slalog.usuarios
        WHERE LOWER(nome) = LOWER(@nome)
      `);

    if (existente.recordset[0]) throw new Error("Este nome de usuário já existe. Faça login.");

    const primeiro = await pool.request().query<{ total: number }>(`
      SELECT COUNT(1) AS total
      FROM slalog.usuarios
    `);

    const senhaHash = await bcrypt.hash(data.senha, 10);
    const aprovado = (primeiro.recordset[0]?.total ?? 0) === 0;

    const criado = await pool
      .request()
      .input("id", sql.UniqueIdentifier, crypto.randomUUID())
      .input("email", sql.NVarChar(255), email)
      .input("nome", sql.NVarChar(150), nome)
      .input("aprovado", sql.Bit, aprovado)
      .input("senhaHash", sql.NVarChar(255), senhaHash)
      .query<PerfilRow>(`
        INSERT INTO slalog.usuarios (
          id,
          email,
          nome,
          aprovado,
          ativo,
          senha_hash,
          created_at,
          updated_at
        )
        OUTPUT inserted.id, inserted.email, inserted.nome, inserted.aprovado, inserted.created_at
        VALUES (
          @id,
          @email,
          @nome,
          @aprovado,
          1,
          @senhaHash,
          SYSDATETIME(),
          SYSDATETIME()
        )
      `);

    if (aprovado) {
      await pool
        .request()
        .input("id", sql.UniqueIdentifier, crypto.randomUUID())
        .input("userId", sql.UniqueIdentifier, criado.recordset[0].id)
        .input("role", sql.NVarChar(20), "admin")
        .query(`
          INSERT INTO slalog.usuarios_papeis (id, user_id, role, created_at)
          VALUES (@id, @userId, @role, SYSDATETIME())
        `);
    }

    return {
      perfil: toPerfil(criado.recordset[0]),
      aprovado,
    };
  });

export const sair = createServerFn({ method: "POST" }).handler(async () => {
  const { clearAuthSession } = await import("@/lib/auth.server");
  await clearAuthSession();
  return { success: true };
});

export const listarPerfis = createServerFn({ method: "GET" }).handler(async () => {
  await requireAdminSession();
  const [{ getPool }] = await Promise.all([import("@/lib/db.server")]);
  const pool = await getPool();
  const result = await pool.query<PerfilRow>(`
    SELECT id, email, nome, aprovado, created_at
    FROM slalog.usuarios
    WHERE ativo = 1
    ORDER BY created_at DESC
  `);
  return result.recordset.map(toPerfil);
});

export const definirAprovacao = createServerFn({ method: "POST" })
  .validator(z.object({ id: z.string().uuid(), aprovado: z.boolean() }))
  .handler(async ({ data }) => {
    await requireAdminSession();
    const [{ getPool, sql }] = await Promise.all([import("@/lib/db.server")]);
    const pool = await getPool();
    await pool
      .request()
      .input("id", sql.UniqueIdentifier, data.id)
      .input("aprovado", sql.Bit, data.aprovado)
      .query(`
        UPDATE slalog.usuarios
        SET aprovado = @aprovado,
            updated_at = SYSDATETIME()
        WHERE id = @id
      `);
  });

export async function obterSessaoAutenticada(): Promise<SessaoAtual> {
  return await requireSession();
}

export async function obterSessaoAprovada(): Promise<SessaoAtual> {
  return await requireApprovedSession();
}