import { useEffect, useState } from "react";
import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import {
  Plus,
  Star,
  DollarSign,
  CalendarCheck,
  Activity,
  Mail,
  Phone,
  Pencil,
  Trash2,
} from "lucide-react";
import { api } from "../lib/api";
import type { Employee } from "../../shared/types";
import { PageHeader, Avatar, Spinner, EmptyState } from "../components/ui";
import { Modal } from "../components/Modal";
import { formatCurrency, cn } from "../lib/format";
import { DEFAULT_WH, DAYS, parseWh } from "../lib/workingHours";

const COLORS = ["#3b66ff", "#f17616", "#10b981", "#a855f7", "#ec4899", "#14b8a6", "#f59e0b", "#6366f1"];

export function EmployeesPage() {
  const qc = useQueryClient();
  const { data, isLoading } = useQuery({ queryKey: ["employees"], queryFn: () => api.employees.list() });
  const { data: servicesData } = useQuery({ queryKey: ["services"], queryFn: () => api.services.list() });
  const [editing, setEditing] = useState<Employee | null>(null);
  const [creating, setCreating] = useState(false);

  const removeMut = useMutation({
    mutationFn: (id: number) => api.employees.remove(id),
    onSuccess: () => qc.invalidateQueries({ queryKey: ["employees"] }),
  });

  return (
    <div className="flex h-full flex-col">
      <PageHeader
        title="Empleados"
        subtitle="Gestiona a tu equipo, sus servicios y mide su rendimiento."
        actions={
          <button
            onClick={() => {
              setEditing(null);
              setCreating(true);
            }}
            className="btn btn-primary"
          >
            <Plus className="h-4 w-4" /> Nuevo empleado
          </button>
        }
      />

      <div className="flex-1 px-5 py-5 sm:px-7">
        {isLoading ? (
          <div className="flex h-40 items-center justify-center"><Spinner /></div>
        ) : !data?.employees.length ? (
          <EmptyState title="Sin empleados" description="Agrega a tu primer especialista." />
        ) : (
          <div className="grid grid-cols-1 gap-4 md:grid-cols-2 xl:grid-cols-3">
            {data.employees.map((e) => (
              <div key={e.id} className="card group p-5">
                <div className="flex items-start gap-3">
                  <Avatar name={e.name} color={e.color} size={48} />
                  <div className="min-w-0 flex-1">
                    <div className="flex items-center gap-2">
                      <h3 className="truncate font-bold text-slate-900">{e.name}</h3>
                      {!e.active && (
                        <span className="chip bg-slate-100 text-slate-500">Inactivo</span>
                      )}
                    </div>
                    <p className="text-xs text-slate-500">{e.role}</p>
                    <div className="mt-1 flex flex-wrap gap-2 text-[11px] text-slate-500">
                      {e.email && (
                        <span className="inline-flex items-center gap-1">
                          <Mail className="h-3 w-3" /> {e.email}
                        </span>
                      )}
                      {e.phone && (
                        <span className="inline-flex items-center gap-1">
                          <Phone className="h-3 w-3" /> {e.phone}
                        </span>
                      )}
                    </div>
                  </div>
                  <div className="flex flex-col gap-1 opacity-0 transition-opacity group-hover:opacity-100">
                    <button
                      onClick={() => {
                        setEditing(e);
                        setCreating(false);
                      }}
                      className="icon-btn rounded-lg p-1.5 text-slate-400 hover:bg-slate-100 hover:text-brand-600"
                    >
                      <Pencil className="h-4 w-4" />
                    </button>
                    <button
                      onClick={() => {
                        if (confirm(`¿Eliminar a ${e.name}?`)) removeMut.mutate(e.id);
                      }}
                      className="icon-btn rounded-lg p-1.5 text-slate-400 hover:bg-rose-50 hover:text-rose-600"
                    >
                      <Trash2 className="h-4 w-4" />
                    </button>
                  </div>
                </div>

                <div className="mt-4 grid grid-cols-3 gap-2 text-center">
                  <Stat icon={DollarSign} color="#10b981" label="Ingresos" value={formatCurrency(e.stats?.revenue_total ?? 0)} />
                  <Stat icon={CalendarCheck} color="#3b66ff" label="Citas" value={String(e.stats?.appointments_completed ?? 0)} />
                  <Stat icon={Star} color="#f59e0b" label="Rating" value={`⭐ ${e.stats?.avg_rating ?? e.rating}`} />
                </div>

                {e.service_ids && e.service_ids.length > 0 && (
                  <div className="mt-3 flex flex-wrap gap-1">
                    {(servicesData?.services ?? [])
                      .filter((s) => e.service_ids!.includes(s.id))
                      .slice(0, 4)
                      .map((s) => (
                        <span
                          key={s.id}
                          className="chip"
                          style={{ background: `${s.color}1a`, color: s.color }}
                        >
                          {s.name}
                        </span>
                      ))}
                    {e.service_ids.length > 4 && (
                      <span className="chip bg-slate-100 text-slate-500">+{e.service_ids.length - 4}</span>
                    )}
                  </div>
                )}
                <div className="mt-3 flex items-center gap-2 text-[11px] text-slate-400">
                  <Activity className="h-3 w-3" />
                  % de citas {e.stats?.share_pct ?? 0}%
                  <div className="ml-1 h-1.5 flex-1 overflow-hidden rounded-full bg-slate-100">
                    <div className="h-full rounded-full bg-brand-500" style={{ width: `${e.stats?.share_pct ?? 0}%` }} />
                  </div>
                </div>
              </div>
            ))}
          </div>
        )}
      </div>

      <EmployeeModal
        open={creating || !!editing}
        employee={editing}
        services={servicesData?.services ?? []}
        onClose={() => {
          setEditing(null);
          setCreating(false);
        }}
      />
    </div>
  );
}

function Stat({
  icon: Icon,
  color,
  label,
  value,
}: {
  icon: React.ComponentType<{ className?: string; style?: React.CSSProperties }>;
  color: string;
  label: string;
  value: string;
}) {
  return (
    <div className="rounded-xl bg-slate-50 px-2 py-2">
      <Icon className="mx-auto h-3.5 w-3.5" style={{ color }} />
      <div className="mt-1 truncate text-sm font-bold text-slate-800">{value}</div>
      <div className="text-[10px] font-medium uppercase tracking-wide text-slate-400">{label}</div>
    </div>
  );
}

function EmployeeModal({
  open,
  employee,
  services,
  onClose,
}: {
  open: boolean;
  employee: Employee | null;
  services: { id: number; name: string; color: string; category: string }[];
  onClose: () => void;
}) {
  const qc = useQueryClient();
  const isEdit = !!employee;
  const [name, setName] = useState("");
  const [role, setRole] = useState("Especialista");
  const [email, setEmail] = useState("");
  const [phone, setPhone] = useState("");
  const [color, setColor] = useState(COLORS[0]);
  const [active, setActive] = useState(true);
  const [svcIds, setSvcIds] = useState<number[]>([]);
  const [specialties, setSpecialties] = useState<string[]>([]);
  const [specialtyInput, setSpecialtyInput] = useState("");
  const [efficiency, setEfficiency] = useState(50);
  const [inheritHours, setInheritHours] = useState(true);
  const [wh, setWh] = useState<Record<number, { start: string; end: string } | null>>({ ...DEFAULT_WH });

  useEffect(() => {
    if (!open) return;
    if (employee) {
      setName(employee.name);
      setRole(employee.role);
      setEmail(employee.email ?? "");
      setPhone(employee.phone ?? "");
      setColor(employee.color);
      setActive(!!employee.active);
      setSvcIds(employee.service_ids ?? []);
      setSpecialties(Array.isArray(employee.specialties) ? employee.specialties : []);
      setEfficiency(typeof employee.efficiency_score === "number" ? employee.efficiency_score : 50);
      const parsed = parseWh(employee.working_hours);
      const hasOwn = !!employee.working_hours && Object.values(parsed).some((v) => v !== null);
      setInheritHours(!hasOwn);
      setWh(hasOwn ? parsed : { ...DEFAULT_WH });
    } else {
      setName("");
      setRole("Especialista");
      setEmail("");
      setPhone("");
      setColor(COLORS[Math.floor(Math.random() * COLORS.length)]);
      setActive(true);
      setSvcIds([]);
      setSpecialties([]);
      setSpecialtyInput("");
      setEfficiency(50);
      setInheritHours(true);
      setWh({ ...DEFAULT_WH });
    }
  }, [open, employee]);

  const mut = useMutation({
    mutationFn: async () => {
      const payload = {
        name,
        role,
        email,
        phone,
        color,
        active,
        service_ids: svcIds,
        specialties,
        efficiency_score: efficiency,
        working_hours: inheritHours ? null : wh,
      };
      if (employee) return api.employees.update(employee.id, payload);
      return api.employees.create(payload);
    },
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: ["employees"] });
      qc.invalidateQueries({ queryKey: ["services"] });
      onClose();
    },
  });

  return (
    <Modal
      open={open}
      onClose={onClose}
      title={isEdit ? "Editar empleado" : "Nuevo empleado"}
      footer={
        <div className="flex items-center justify-end gap-2">
          <button onClick={onClose} className="btn btn-ghost">Cancelar</button>
          <button onClick={() => mut.mutate()} className="btn btn-primary" disabled={!name.trim() || mut.isPending}>
            {mut.isPending ? <Spinner /> : isEdit ? "Guardar" : "Crear"}
          </button>
        </div>
      }
    >
      <div className="space-y-4">
        <div className="flex items-center gap-3">
          <Avatar name={name || "?"} color={color} size={56} />
          <div className="flex-1">
            <label className="label">Color</label>
            <div className="flex flex-wrap gap-1.5">
              {COLORS.map((c) => (
                <button
                  key={c}
                  type="button"
                  onClick={() => setColor(c)}
                  className={cn(
                    "h-7 w-7 rounded-full transition-transform",
                    color === c && "ring-2 ring-offset-2 ring-slate-400 scale-110"
                  )}
                  style={{ background: c }}
                />
              ))}
            </div>
          </div>
        </div>
        <div className="grid gap-3 sm:grid-cols-2">
          <div>
            <label className="label">Nombre *</label>
            <input className="input" value={name} onChange={(e) => setName(e.target.value)} />
          </div>
          <div>
            <label className="label">Puesto</label>
            <input className="input" value={role} onChange={(e) => setRole(e.target.value)} />
          </div>
          <div>
            <label className="label">Correo</label>
            <input className="input" value={email} onChange={(e) => setEmail(e.target.value)} />
          </div>
          <div>
            <label className="label">Teléfono</label>
            <input className="input" value={phone} onChange={(e) => setPhone(e.target.value)} />
          </div>
        </div>
        <div>
          <label className="label">Servicios que ofrece</label>
          <div className="flex max-h-44 flex-wrap gap-1.5 overflow-y-auto rounded-xl border border-slate-100 p-2">
            {services.map((s) => {
              const on = svcIds.includes(s.id);
              return (
                <button
                  key={s.id}
                  type="button"
                  onClick={() => setSvcIds((arr) => (on ? arr.filter((x) => x !== s.id) : [...arr, s.id]))}
                  className={cn(
                    "chip transition-colors",
                    on ? "text-white" : "bg-slate-100 text-slate-600 hover:bg-slate-200"
                  )}
                  style={on ? { background: s.color } : undefined}
                >
                  {s.name}
                </button>
              );
            })}
          </div>
        </div>
        <div>
          <label className="label">Especialidades</label>
          <div className="flex flex-wrap items-center gap-1.5 rounded-xl border border-slate-100 p-2">
            {specialties.map((sp) => (
              <span key={sp} className="chip bg-brand-50 text-brand-700">
                {sp}
                <button
                  type="button"
                  onClick={() => setSpecialties((a) => a.filter((x) => x !== sp))}
                  className="ml-0.5 text-brand-400 hover:text-brand-700"
                >
                  ×
                </button>
              </span>
            ))}
            <input
              className="min-w-[120px] flex-1 bg-transparent text-sm outline-none"
              placeholder="Ej. Coloración y pulsa Enter"
              value={specialtyInput}
              onChange={(e) => setSpecialtyInput(e.target.value)}
              onKeyDown={(e) => {
                if (e.key === "Enter" && specialtyInput.trim()) {
                  e.preventDefault();
                  setSpecialties((a) => [...new Set([...a, specialtyInput.trim()])]);
                  setSpecialtyInput("");
                }
              }}
            />
          </div>
          <p className="mt-1 text-[11px] text-slate-500">Etiquetas que el algoritmo compara con la categoría y el nombre del servicio.</p>
        </div>
        <div>
          <label className="label">
            Eficiencia <span className="ml-1 text-brand-700">{efficiency}</span>
          </label>
          <input
            type="range"
            min={0}
            max={100}
            value={efficiency}
            onChange={(e) => setEfficiency(Number(e.target.value))}
            className="w-full accent-brand-500"
          />
          <p className="mt-1 text-[11px] text-slate-500">Qué tan rápido/hábil es. El algoritmo premia valores altos cuando hay empate por disponibilidad.</p>
        </div>
        <div>
          <label className="flex cursor-pointer items-center gap-2">
            <input
              type="checkbox"
              className="h-4 w-4 accent-brand-500"
              checked={inheritHours}
              onChange={(e) => setInheritHours(e.target.checked)}
            />
            <span className="text-sm font-bold text-slate-800">Heredar horario del negocio</span>
          </label>
          {!inheritHours && (
            <div className="mt-2 space-y-1.5">
              {DAYS.map(({ n, label }) => {
                const on = !!wh[n];
                return (
                  <div key={n} className="flex items-center gap-2 rounded-lg border border-slate-100 px-2 py-1.5">
                    <label className="flex w-24 cursor-pointer items-center gap-2 text-xs font-semibold text-slate-700">
                      <input
                        type="checkbox"
                        className="h-4 w-4 accent-brand-500"
                        checked={on}
                        onChange={() =>
                          setWh({ ...wh, [n]: wh[n] ? null : { start: "09:00", end: "18:00" } })
                        }
                      />
                      {label}
                    </label>
                    {on ? (
                      <div className="flex items-center gap-1.5">
                        <input
                          type="time"
                          className="input !w-auto !py-1 text-xs"
                          value={wh[n]!.start}
                          onChange={(e) =>
                            setWh({ ...wh, [n]: { ...(wh[n] as { start: string; end: string }), start: e.target.value } })
                          }
                        />
                        <span className="text-xs text-slate-400">a</span>
                        <input
                          type="time"
                          className="input !w-auto !py-1 text-xs"
                          value={wh[n]!.end}
                          onChange={(e) =>
                            setWh({ ...wh, [n]: { ...(wh[n] as { start: string; end: string }), end: e.target.value } })
                          }
                        />
                      </div>
                    ) : (
                      <span className="text-xs font-medium text-slate-400">Cerrado</span>
                    )}
                  </div>
                );
              })}
            </div>
          )}
        </div>
        <label className="flex items-center gap-2 text-sm font-medium text-slate-700">
          <input type="checkbox" checked={active} onChange={(e) => setActive(e.target.checked)} />
          Activo (puede recibir citas)
        </label>
      </div>
    </Modal>
  );
}