"use client";

import { useState } from "react";
import { useQuery, useQueryClient } from "@tanstack/react-query";
import { useBaby } from "@/contexts/baby-context";
import { format } from "date-fns";
import { fr } from "date-fns/locale";
import { Check, Trash2, X } from "lucide-react";

interface Tooth {
  id: string;
  babyId: string;
  code: string;
  appearedAt: string;
  notes: string | null;
}

const UPPER_CODES = ["u5l", "u4l", "u3l", "u2l", "u1l", "u1r", "u2r", "u3r", "u4r", "u5r"];
const LOWER_CODES = ["l5l", "l4l", "l3l", "l2l", "l1l", "l1r", "l2r", "l3r", "l4r", "l5r"];

const TOOTH_NAMES: Record<string, string> = {
  "1": "Incisive centrale",
  "2": "Incisive latérale",
  "3": "Canine",
  "4": "Première molaire",
  "5": "Deuxième molaire",
};

const ERUPTION_AGES: Record<string, string> = {
  "1": "6–12 mois",
  "2": "9–16 mois",
  "3": "16–23 mois",
  "4": "14–18 mois",
  "5": "23–31 mois",
};

function getToothNumber(code: string): string {
  // code is like "u1l", "l3r" — digit is at index 1
  return code[1];
}

function getToothLabel(code: string): string {
  const num = getToothNumber(code);
  const jaw = code[0] === "u" ? "sup." : "inf.";
  const side = code[2] === "l" ? "gauche" : "droite";
  return `${TOOTH_NAMES[num]} ${jaw} ${side}`;
}

const inputCls =
  "w-full px-3 py-2 rounded-lg border border-slate-200 dark:border-slate-700 text-sm focus:outline-none focus:ring-2 focus:ring-emerald-400 bg-white dark:bg-slate-800 text-slate-900 dark:text-slate-100";

type ActiveState =
  | { type: "form"; code: string; date: string; notes: string }
  | { type: "detail"; code: string }
  | null;

export default function TeethPage() {
  const qc = useQueryClient();
  const { selectedBaby: baby } = useBaby();
  const [active, setActive] = useState<ActiveState>(null);
  const [saving, setSaving] = useState(false);
  const [deleting, setDeleting] = useState<string | null>(null);

  const { data: teeth = [] } = useQuery<Tooth[]>({
    queryKey: ["teeth", baby?.id],
    queryFn: () =>
      fetch(`/api/teeth?babyId=${baby!.id}`).then((r) => r.json()),
    enabled: !!baby?.id,
  });

  const appearedCodes = new Set(teeth.map((t) => t.code));
  const count = appearedCodes.size;

  function getToothData(code: string): Tooth | undefined {
    return teeth.find((t) => t.code === code);
  }

  function handleToothClick(code: string) {
    if (appearedCodes.has(code)) {
      setActive(active?.type === "detail" && active.code === code ? null : { type: "detail", code });
    } else {
      const today = format(new Date(), "yyyy-MM-dd");
      setActive(
        active?.type === "form" && active.code === code
          ? null
          : { type: "form", code, date: today, notes: "" }
      );
    }
  }

  async function handleSave(e: React.FormEvent) {
    e.preventDefault();
    if (!baby || active?.type !== "form") return;
    setSaving(true);
    await fetch("/api/teeth", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        babyId: baby.id,
        code: active.code,
        appearedAt: new Date(active.date).toISOString(),
        notes: active.notes || null,
      }),
    });
    qc.invalidateQueries({ queryKey: ["teeth", baby.id] });
    setSaving(false);
    setActive(null);
  }

  async function handleDelete(code: string) {
    if (!baby) return;
    setDeleting(code);
    await fetch(`/api/teeth/${code}?babyId=${baby.id}`, { method: "DELETE" });
    qc.invalidateQueries({ queryKey: ["teeth", baby.id] });
    setDeleting(null);
    setActive(null);
  }

  function ToothSquare({ code }: { code: string }) {
    const appeared = appearedCodes.has(code);
    const num = getToothNumber(code);
    const isActive = active !== null && active.code === code;

    return (
      <button
        onClick={() => handleToothClick(code)}
        title={`${getToothLabel(code)} — ${ERUPTION_AGES[num]}`}
        className={`
          relative aspect-square w-full rounded-xl border-2 transition-all duration-150 flex flex-col items-center justify-center gap-0.5 text-xs font-semibold
          ${appeared
            ? "bg-emerald-50 dark:bg-emerald-950 border-emerald-400 dark:border-emerald-600 text-emerald-700 dark:text-emerald-300"
            : "bg-slate-100 dark:bg-slate-800 border-dashed border-slate-300 dark:border-slate-600 text-slate-400 dark:text-slate-500"
          }
          ${isActive ? "ring-2 ring-offset-1 ring-emerald-500 dark:ring-emerald-400" : "hover:border-emerald-400 dark:hover:border-emerald-500"}
        `}
      >
        {appeared ? (
          <>
            <Check className="w-4 h-4" />
            <span className="text-[10px] leading-tight">{num}</span>
          </>
        ) : (
          <span className="text-sm">{num}</span>
        )}
      </button>
    );
  }

  const activeToothLabel = active ? getToothLabel(active.code) : "";
  const activeToothNum = active ? getToothNumber(active.code) : "";

  return (
    <div className="p-4 md:p-8 pb-28 md:pb-8 max-w-lg mx-auto">
      {/* Header */}
      <div className="mb-6">
        <h1 className="text-2xl font-bold text-slate-900 dark:text-slate-100">Dents</h1>
        <p className="text-sm text-slate-500 dark:text-slate-400 mt-0.5">{baby?.name}</p>
      </div>

      {/* Progress */}
      <div className="mb-6">
        <div className="flex items-center justify-between mb-2">
          <span className="text-sm font-medium text-slate-700 dark:text-slate-200">
            {count} / 20 dents apparues
          </span>
          <span className="text-sm text-slate-500 dark:text-slate-400">
            {Math.round((count / 20) * 100)} %
          </span>
        </div>
        <div className="h-2.5 bg-slate-100 dark:bg-slate-800 rounded-full overflow-hidden">
          <div
            className="h-full bg-emerald-500 rounded-full transition-all duration-500"
            style={{ width: `${(count / 20) * 100}%` }}
          />
        </div>
      </div>

      {/* Diagram */}
      <div className="bg-white dark:bg-slate-900 rounded-2xl border border-slate-200 dark:border-slate-700 p-4 space-y-3">
        {/* Upper jaw label */}
        <p className="text-[10px] font-semibold uppercase tracking-wider text-slate-400 dark:text-slate-600 text-center">
          Mâchoire supérieure
        </p>
        <div className="grid grid-cols-10 gap-1.5">
          {UPPER_CODES.map((code) => (
            <ToothSquare key={code} code={code} />
          ))}
        </div>

        <div className="border-t border-dashed border-slate-200 dark:border-slate-700" />

        <div className="grid grid-cols-10 gap-1.5">
          {LOWER_CODES.map((code) => (
            <ToothSquare key={code} code={code} />
          ))}
        </div>
        {/* Lower jaw label */}
        <p className="text-[10px] font-semibold uppercase tracking-wider text-slate-400 dark:text-slate-600 text-center">
          Mâchoire inférieure
        </p>
      </div>

      {/* Legend */}
      <div className="mt-3 flex items-center gap-4 text-xs text-slate-500 dark:text-slate-400">
        <span className="flex items-center gap-1.5">
          <span className="w-3.5 h-3.5 rounded border-2 border-dashed border-slate-300 dark:border-slate-600 inline-block" />
          Non apparue
        </span>
        <span className="flex items-center gap-1.5">
          <span className="w-3.5 h-3.5 rounded border-2 border-emerald-400 bg-emerald-50 dark:bg-emerald-950 inline-block" />
          Apparue
        </span>
      </div>

      {/* Inline panel for form or detail */}
      {active && (
        <div className="mt-4 bg-white dark:bg-slate-900 border border-slate-200 dark:border-slate-700 rounded-xl p-4">
          <div className="flex items-center justify-between mb-3">
            <div>
              <p className="text-sm font-semibold text-slate-800 dark:text-slate-100">
                {activeToothLabel}
              </p>
              <p className="text-xs text-slate-400 dark:text-slate-500 mt-0.5">
                Éruption typique : {ERUPTION_AGES[activeToothNum]}
              </p>
            </div>
            <button
              onClick={() => setActive(null)}
              className="p-1.5 rounded-lg text-slate-400 hover:bg-slate-100 dark:hover:bg-slate-800 transition"
            >
              <X className="w-4 h-4" />
            </button>
          </div>

          {active.type === "form" ? (
            <form onSubmit={handleSave} className="space-y-3">
              <div>
                <label className="block text-xs font-medium text-slate-600 dark:text-slate-300 mb-1">
                  Date d&apos;apparition <span className="text-red-400">*</span>
                </label>
                <input
                  type="date"
                  required
                  value={active.date}
                  onChange={(e) =>
                    setActive((prev) =>
                      prev?.type === "form" ? { ...prev, date: e.target.value } : prev
                    )
                  }
                  className={inputCls}
                />
              </div>
              <div>
                <label className="block text-xs font-medium text-slate-600 dark:text-slate-300 mb-1">
                  Notes <span className="text-slate-400 font-normal">(optionnel)</span>
                </label>
                <input
                  type="text"
                  value={active.notes}
                  onChange={(e) =>
                    setActive((prev) =>
                      prev?.type === "form" ? { ...prev, notes: e.target.value } : prev
                    )
                  }
                  placeholder="Observations..."
                  className={inputCls}
                />
              </div>
              <div className="flex gap-2 pt-1">
                <button
                  type="button"
                  onClick={() => setActive(null)}
                  className="flex-1 py-2 border border-slate-200 dark:border-slate-700 rounded-lg text-sm text-slate-600 dark:text-slate-300 hover:bg-slate-50 dark:hover:bg-slate-800 transition"
                >
                  Annuler
                </button>
                <button
                  type="submit"
                  disabled={saving}
                  className="flex-1 py-2 bg-emerald-600 text-white rounded-lg text-sm font-medium hover:bg-emerald-700 transition disabled:opacity-60"
                >
                  {saving ? "..." : "Enregistrer"}
                </button>
              </div>
            </form>
          ) : (
            (() => {
              const tooth = getToothData(active.code);
              if (!tooth) return null;
              return (
                <div className="space-y-2">
                  <p className="text-sm text-slate-700 dark:text-slate-200">
                    Apparue le{" "}
                    <span className="font-semibold">
                      {format(new Date(tooth.appearedAt), "d MMMM yyyy", { locale: fr })}
                    </span>
                  </p>
                  {tooth.notes && (
                    <p className="text-sm text-slate-500 dark:text-slate-400">{tooth.notes}</p>
                  )}
                  <button
                    onClick={() => handleDelete(active.code)}
                    disabled={deleting === active.code}
                    className="flex items-center gap-2 mt-2 px-3 py-1.5 rounded-lg text-sm text-red-600 dark:text-red-400 hover:bg-red-50 dark:hover:bg-red-950 transition disabled:opacity-50"
                  >
                    <Trash2 className="w-3.5 h-3.5" />
                    {deleting === active.code ? "Suppression..." : "Supprimer"}
                  </button>
                </div>
              );
            })()
          )}
        </div>
      )}
    </div>
  );
}