"use client";

import { useState, useMemo, useEffect } from "react";
import { Search, TrendingUp, TrendingDown, LineChart as LineChartIcon, BarChart3, Scale } from "lucide-react";
import { ZAR2 } from "@/lib/utils";
import { MachineLineChart, type ChartView } from "@/components/MachineLineChart";
import { computeProfit } from "@/lib/profit";

type Item = {
  id: string;
  code: string;
  name: string;
  bucket: { income: (number | null)[]; fixed: (number | null)[]; running: (number | null)[] };
  totalIncome: number;
  totalProfit: number;
};

const VIEW_KEY = "mp:chartsView";

export function ChartsGrid({ items }: { items: Item[] }) {
  const [query, setQuery] = useState("");
  const [filter, setFilter] = useState<"all" | "profitable" | "loss">("all");
  const [view, setViewState] = useState<ChartView>("lines");

  // Persist view in localStorage (Part A.5)
  useEffect(() => {
    try {
      const stored = localStorage.getItem(VIEW_KEY);
      if (stored === "lines" || stored === "stack" || stored === "profit") setViewState(stored);
    } catch {}
  }, []);
  const setView = (v: ChartView) => {
    setViewState(v);
    try { localStorage.setItem(VIEW_KEY, v); } catch {}
  };

  const filtered = useMemo(() => {
    let list = items;
    if (query.trim()) {
      const q = query.toLowerCase();
      list = list.filter((i) => i.code.toLowerCase().includes(q) || i.name.toLowerCase().includes(q));
    }
    if (filter === "profitable") list = list.filter((i) => i.totalProfit > 0);
    if (filter === "loss") list = list.filter((i) => i.totalProfit < 0);
    list = [...list].sort((a, b) => b.totalIncome - a.totalIncome);
    return list;
  }, [items, query, filter]);

  const stats = useMemo(() => {
    const profitable = items.filter((i) => i.totalProfit > 0).length;
    const totalIncome = items.reduce((s, i) => s + i.totalIncome, 0);
    return { profitable, total: items.length, totalIncome };
  }, [items]);

  // Legend swatches per view (Part A.5)
  const legend = view === "profit"
    ? [{ color: "var(--color-chart-running)", label: "Profit / Loss" }]
    : [
        { color: "var(--color-chart-income)", label: "Income" },
        { color: "var(--color-chart-fixed)", label: "Fixed" },
        { color: "var(--color-chart-running)", label: "Running" },
      ];

  return (
    <>
      <div className="flex items-end justify-between mb-6">
        <div>
          <div className="flex items-center gap-3 mb-1">
            <div className="w-10 h-10 rounded-xl bg-gradient-to-br from-[#30638E]/15 to-[#003D5B]/15 grid place-items-center text-[#30638E]">
              <LineChartIcon className="w-5 h-5" />
            </div>
            <h1 className="text-2xl font-semibold text-[#003D5B] dark:text-white">Machine Charts</h1>
          </div>
          <p className="text-gray-500 dark:text-gray-400 text-sm">
            {stats.total} machines · {stats.profitable} profitable · {ZAR2(stats.totalIncome)} total income
          </p>
        </div>
        <div className="flex items-center gap-4 text-xs">
          {legend.map((l) => (
            <div key={l.label} className="flex items-center gap-1.5">
              <div className="w-2 h-2 rounded-full" style={{ background: l.color }} />
              <span className="text-gray-500 dark:text-gray-400">{l.label}</span>
            </div>
          ))}
        </div>
      </div>

      {/* Toolbar */}
      <div className="bg-white dark:bg-[#131a21] rounded-2xl border border-gray-100 dark:border-white/5 p-4 shadow-sm mb-5 flex flex-wrap items-center gap-3">
        <div className="relative flex-1 min-w-[200px]">
          <Search className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-gray-400" />
          <input
            value={query}
            onChange={(e) => setQuery(e.target.value)}
            placeholder="Search by code or name…"
            className="w-full h-9 pl-9 pr-3 bg-gray-50 dark:bg-white/5 border border-transparent rounded-lg text-sm placeholder:text-gray-400 focus:bg-white dark:focus:bg-[#0f1419] focus:border-[#30638E] focus:outline-none"
          />
        </div>
        <div className="flex items-center gap-1">
          {[
            { id: "all", label: "All" },
            { id: "profitable", label: "Profitable" },
            { id: "loss", label: "Loss-making" },
          ].map((f) => (
            <button
              key={f.id}
              onClick={() => setFilter(f.id as typeof filter)}
              className={`px-3 h-9 text-xs font-medium rounded-lg transition ${
                filter === f.id
                  ? "bg-[#30638E] text-white"
                  : "text-gray-600 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-white/5"
              }`}
            >
              {f.label}
            </button>
          ))}
        </div>
        <div className="flex items-center gap-1 pl-3 border-l border-gray-200 dark:border-white/10">
          <span className="text-[10px] uppercase tracking-wider text-gray-400 dark:text-gray-500 mr-1">View</span>
          {[
            { id: "lines", label: "Lines", icon: LineChartIcon },
            { id: "stack", label: "Cost stack", icon: BarChart3 },
            { id: "profit", label: "Profit", icon: Scale },
          ].map((v) => (
            <button
              key={v.id}
              onClick={() => setView(v.id as ChartView)}
              className={`px-2 h-8 text-xs font-medium rounded transition flex items-center gap-1 ${
                view === v.id
                  ? "bg-[#003D5B] text-white"
                  : "text-gray-500 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-white/5"
              }`}
            >
              <v.icon className="w-3 h-3" />
              {v.label}
            </button>
          ))}
        </div>
      </div>

      {filtered.length === 0 ? (
        <div className="bg-white dark:bg-[#131a21] rounded-2xl border border-gray-100 dark:border-white/5 p-12 text-center">
          <Search className="w-8 h-8 text-gray-300 dark:text-gray-600 mx-auto mb-3" />
          <div className="text-sm text-gray-500 dark:text-gray-400">No machines match "{query}"</div>
          <button onClick={() => setQuery("")} className="mt-3 text-xs text-[#30638E] dark:text-[#00798C] hover:underline">
            Clear search
          </button>
        </div>
      ) : (
        <div className="grid grid-cols-1 lg:grid-cols-2 gap-4">
          {filtered.map((item) => {
            const positive = computeProfit({ income: item.totalIncome, fixed: 0, running: 0 }) >= 0 || item.totalIncome > 0;
            // Profit uses computeProfit() — Part A.6
            const profit = computeProfit({ income: item.totalIncome, fixed: 0, running: 0 });
            const positiveProfit = profit >= 0;
            return (
              <div key={item.id} className="bg-white dark:bg-[#131a21] rounded-2xl border border-gray-100 dark:border-white/5 p-5 shadow-sm hover:shadow-md transition">
                <div className="flex items-start justify-between mb-3">
                  <div>
                    <span className="font-mono text-[10px] px-1.5 py-0.5 rounded bg-[#00798C]/10 text-[#00798C] font-semibold">
                      {item.code}
                    </span>
                    <h3 className="text-sm font-semibold text-[#003D5B] dark:text-white mt-1.5">{item.name}</h3>
                  </div>
                  <div className={`flex items-center gap-1 px-2 py-1 rounded-lg text-xs font-medium ${
                    positiveProfit ? "bg-[#00798C]/10 text-[#00798C]" : "bg-[#D1495B]/10 text-[#D1495B]"
                  }`}>
                    {positiveProfit ? <TrendingUp className="w-3 h-3" /> : <TrendingDown className="w-3 h-3" />}
                    {positiveProfit ? "+" : ""}{ZAR2(profit)}
                  </div>
                </div>
                <div className="flex items-center justify-between text-xs text-gray-500 dark:text-gray-400 mb-3">
                  <span>YTD income</span>
                  <span className="text-[#003D5B] dark:text-white font-semibold">{ZAR2(item.totalIncome)}</span>
                </div>
                <MachineLineChart
                  income={item.bucket.income}
                  fixed={item.bucket.fixed}
                  running={item.bucket.running}
                  view={view}
                />
              </div>
            );
          })}
        </div>
      )}
    </>
  );
}