"use client";

import { useState, useEffect, useMemo } from "react";
import { api } from "@/lib/api";
import { Spinner } from "@/components/ui/Spinner";
import type { Exercise } from "@/lib/types";

interface ExcludedExercisesStepProps {
  selectedIds: number[];
  onChange: (ids: number[]) => void;
}

export function ExcludedExercisesStep({
  selectedIds,
  onChange,
}: ExcludedExercisesStepProps) {
  const [exercises, setExercises] = useState<Exercise[]>([]);
  const [loading, setLoading] = useState(true);
  const [search, setSearch] = useState("");

  useEffect(() => {
    async function fetchExercises() {
      try {
        const data = await api.getExercises();
        setExercises(data);
      } catch (err) {
        console.error("Failed to fetch exercises:", err);
      } finally {
        setLoading(false);
      }
    }
    fetchExercises();
  }, []);

  const excludedExercises = useMemo(
    () => exercises.filter((e) => selectedIds.includes(e.id)),
    [exercises, selectedIds]
  );

  const searchResults = useMemo(() => {
    if (search.length < 2) return [];
    const query = search.toLowerCase();
    return exercises.filter((e) =>
      e.name.toLowerCase().includes(query)
    );
  }, [exercises, search]);

  const toggle = (id: number) => {
    if (selectedIds.includes(id)) {
      onChange(selectedIds.filter((i) => i !== id));
    } else {
      onChange([...selectedIds, id]);
    }
  };

  if (loading) {
    return (
      <div className="flex items-center justify-center py-20">
        <Spinner size="lg" />
      </div>
    );
  }

  return (
    <div>
      <h2 className="text-2xl font-bold text-zinc-100 mb-2">
        Exclude Exercises
      </h2>
      <p className="text-zinc-400 mb-6">
        Search for exercises you can&apos;t or won&apos;t do. They&apos;ll never
        appear in your generated workouts.
      </p>

      {/* Excluded chips */}
      <div className="mb-4">
        {excludedExercises.length === 0 ? (
          <p className="text-sm text-zinc-500 italic">
            No exercises excluded yet
          </p>
        ) : (
          <div className="flex flex-wrap gap-2">
            {excludedExercises.map((ex) => (
              <button
                key={ex.id}
                type="button"
                onClick={() => toggle(ex.id)}
                className="inline-flex items-center gap-1.5 px-3 py-1.5 rounded-full text-sm font-medium bg-red-500/15 text-red-400 border border-red-500/30 hover:bg-red-500/25 transition-colors"
              >
                {ex.name}
                <svg
                  xmlns="http://www.w3.org/2000/svg"
                  width="14"
                  height="14"
                  viewBox="0 0 24 24"
                  fill="none"
                  stroke="currentColor"
                  strokeWidth="2"
                  strokeLinecap="round"
                  strokeLinejoin="round"
                >
                  <line x1="18" y1="6" x2="6" y2="18" />
                  <line x1="6" y1="6" x2="18" y2="18" />
                </svg>
              </button>
            ))}
          </div>
        )}
      </div>

      {/* Search input */}
      <input
        type="text"
        value={search}
        onChange={(e) => setSearch(e.target.value)}
        placeholder="Search exercises..."
        className="w-full px-4 py-3 rounded-xl bg-zinc-900 border border-zinc-700/50 text-zinc-100 placeholder-zinc-500 focus:outline-none focus:border-zinc-500 transition-colors mb-4"
      />

      {/* Search results */}
      {search.length >= 2 && (
        <div className="max-h-80 overflow-y-auto rounded-xl border border-zinc-700/50">
          {searchResults.length === 0 ? (
            <p className="p-4 text-sm text-zinc-500">
              No exercises match &quot;{search}&quot;
            </p>
          ) : (
            searchResults.map((ex) => {
              const isExcluded = selectedIds.includes(ex.id);
              return (
                <button
                  key={ex.id}
                  type="button"
                  onClick={() => toggle(ex.id)}
                  className={`w-full text-left px-4 py-3 flex items-center justify-between border-b border-zinc-800 last:border-b-0 transition-colors ${
                    isExcluded
                      ? "bg-red-500/10 hover:bg-red-500/15"
                      : "bg-zinc-900 hover:bg-zinc-800/50"
                  }`}
                >
                  <div>
                    <span
                      className={`text-sm font-medium ${
                        isExcluded ? "text-red-400" : "text-zinc-100"
                      }`}
                    >
                      {ex.name}
                    </span>
                    {ex.muscle_groups && (
                      <span className="ml-2 text-xs text-zinc-500">
                        {ex.muscle_groups}
                      </span>
                    )}
                  </div>
                  {isExcluded && (
                    <span className="text-xs text-red-400 font-medium">
                      Excluded
                    </span>
                  )}
                </button>
              );
            })
          )}
        </div>
      )}
    </div>
  );
}