"use client";

import Link from "next/link";
import { FormEvent, useEffect, useState } from "react";
import { api, SettingsStatus, Subject } from "@/lib/api";
import { Shell } from "@/components/Shell";
import { Button, Card, Input, Label } from "@/components/ui";

export default function DashboardPage() {
  const [subjects, setSubjects] = useState<Subject[]>([]);
  const [settings, setSettings] = useState<SettingsStatus | null>(null);
  const [name, setName] = useState("");
  const [editingSubject, setEditingSubject] = useState<Subject | null>(null);
  const [editName, setEditName] = useState("");
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState("");

  async function load() {
    setError("");
    try {
      const [subjectList, status] = await Promise.all([api.subjects(), api.settings()]);
      setSubjects(subjectList);
      setSettings(status);
    } catch (err) {
      setError(err instanceof Error ? err.message : "No se pudo conectar con la API");
    } finally {
      setLoading(false);
    }
  }

  useEffect(() => { load(); }, []);

  async function createSubject(event: FormEvent) {
    event.preventDefault();
    if (!name.trim()) return;
    try {
      setError("");
      await api.createSubject(name.trim());
      setName("");
      await load();
    } catch (err) {
      setError(err instanceof Error ? err.message : "No se pudo crear la materia");
    }
  }

  function startEdit(subject: Subject) {
    setEditingSubject(subject);
    setEditName(subject.name);
    setError("");
  }

  async function saveEdit(event: FormEvent) {
    event.preventDefault();
    if (!editingSubject || !editName.trim()) return;
    try {
      setError("");
      await api.updateSubject(editingSubject.id, editName.trim());
      setEditingSubject(null);
      setEditName("");
      await load();
    } catch (err) {
      setError(err instanceof Error ? err.message : "No se pudo editar la materia");
    }
  }

  async function deleteSubject(subject: Subject) {
    const confirmed = window.confirm(`Eliminar la materia "${subject.name}" tambien borrara todas sus semanas, archivos subidos, Markdown procesado y exports. Esta accion no se puede deshacer.`);
    if (!confirmed) return;
    try {
      setError("");
      await api.deleteSubject(subject.id);
      if (editingSubject?.id === subject.id) setEditingSubject(null);
      await load();
    } catch (err) {
      setError(err instanceof Error ? err.message : "No se pudo eliminar la materia");
    }
  }

  return (
    <Shell>
      <div className="grid gap-6 lg:grid-cols-[1fr_360px]">
        <section>
          <div className="mb-6">
            <p className="text-sm uppercase tracking-[0.25em] text-blue-300">Plataforma personal</p>
            <h1 className="mt-2 text-4xl font-bold tracking-tight">Materias</h1>
            <p className="mt-3 max-w-2xl text-slate-400">Organiza clases, PDFs, audios y videos por materia y semana. Todo termina en Markdown listo para ingesta en LLM.</p>
          </div>

          {error && <Card className="mb-4 border-red-500/30 bg-red-500/10 text-red-200">{error}</Card>}
          {loading ? <Card>Cargando...</Card> : (
            <div className="grid gap-4 md:grid-cols-2">
              {subjects.map((subject) => (
                <Card key={subject.id} className="transition hover:border-blue-400/40 hover:bg-blue-500/10">
                  <div className="text-xl font-semibold">{subject.name}</div>
                  <div className="mt-2 text-sm text-slate-400">{subject.slug}</div>
                  <div className="mt-5 flex flex-wrap gap-2 text-sm">
                    <Link className="rounded-lg bg-blue-600 px-3 py-2 font-medium text-white hover:bg-blue-500" href={`/subjects/${subject.id}`}>Abrir materia</Link>
                    <button className="rounded-lg border border-white/10 px-3 py-2 text-slate-200 hover:bg-white/10" type="button" onClick={() => startEdit(subject)}>Editar</button>
                    <button className="rounded-lg border border-red-400/30 px-3 py-2 text-red-200 hover:bg-red-500/10" type="button" onClick={() => deleteSubject(subject)}>Eliminar</button>
                  </div>
                </Card>
              ))}
              {subjects.length === 0 && <Card className="md:col-span-2">No hay materias todavia. Crea la primera para empezar.</Card>}
            </div>
          )}
        </section>

        <aside className="space-y-4">
          {editingSubject && (
            <Card>
              <h2 className="text-lg font-semibold">Editar materia</h2>
              <p className="mt-1 text-sm text-slate-400">Solo cambia el nombre visible. La carpeta interna queda igual para mantener rutas estables.</p>
              <form className="mt-4 space-y-3" onSubmit={saveEdit}>
                <Label>Nombre</Label>
                <Input value={editName} onChange={(event) => setEditName(event.target.value)} />
                <div className="flex gap-2">
                  <Button className="flex-1" disabled={!editName.trim()}>Guardar</Button>
                  <button className="flex-1 rounded-xl border border-white/10 px-4 py-2 hover:bg-white/10" type="button" onClick={() => setEditingSubject(null)}>Cancelar</button>
                </div>
              </form>
            </Card>
          )}

          <Card>
            <h2 className="text-lg font-semibold">Nueva materia</h2>
            <form className="mt-4 space-y-3" onSubmit={createSubject}>
              <Label>Nombre</Label>
              <Input value={name} onChange={(event) => setName(event.target.value)} placeholder="Ej. Comportamiento Organizacional" />
              <Button className="w-full" disabled={!name.trim()}>Crear materia</Button>
            </form>
          </Card>

          <Card>
            <h2 className="text-lg font-semibold">Servicios</h2>
            <div className="mt-4 space-y-3 text-sm">
              <div className="flex justify-between"><span>Deepgram</span><span className={settings?.deepgram_configured ? "text-emerald-300" : "text-amber-300"}>{settings?.deepgram_configured ? "Configurado" : "Falta key"}</span></div>
              <div className="flex justify-between"><span>Mistral OCR</span><span className={settings?.mistral_configured ? "text-emerald-300" : "text-amber-300"}>{settings?.mistral_configured ? "Configurado" : "Falta key"}</span></div>
            </div>
          </Card>
        </aside>
      </div>
    </Shell>
  );
}