"use client";

import { useEffect, useState, useCallback, useMemo } from "react";
import Link from "next/link";
import { api } from "@/lib/api";
import type { Negotiation } from "@/lib/types";
import { FEATURE_LABELS, STATUS_COLORS, STATUS_LABELS, relativeTime } from "@/lib/utils";
import Sidebar from "@/components/Sidebar";

function Icon({ name, className = "" }: { name: string; className?: string }) {
  return <span className={`material-symbols-outlined ${className}`}>{name}</span>;
}

const FEATURE_ICONS: Record<string, string> = {
  scheduling: "calendar_month",
  expenses: "account_balance_wallet",
  freelance: "work",
  roommate: "home",
  trip: "flight_takeoff",
  marketplace: "store",
  collaborative: "groups",
  conflict: "gavel",
  generic: "hub",
};

const STATUS_FILTERS = [
  { key: "all", label: "All Statuses", dot: "" },
  { key: "resolved", label: "Resolved", dot: "bg-emerald-400" },
  { key: "escalated", label: "Escalated", dot: "bg-rose-400" },
  { key: "active", label: "In Progress", dot: "bg-amber-400" },
  { key: "pending", label: "Pending", dot: "bg-slate-400" },
];

const STATUS_BADGE: Record<string, string> = {
  resolved: "text-emerald-400 bg-emerald-500/10 border-emerald-500/20",
  escalated: "text-rose-400 bg-rose-500/10 border-rose-500/20",
  active: "text-amber-400 bg-amber-500/10 border-amber-500/20",
  pending: "text-slate-400 bg-white/5 border-white/10",
};

const PAGE_SIZE = 8;

export default function HistoryPage() {
  const [negotiations, setNegotiations] = useState<Negotiation[]>([]);
  const [loading, setLoading] = useState(true);
  const [search, setSearch] = useState("");
  const [statusFilter, setStatusFilter] = useState("all");
  const [page, setPage] = useState(1);

  const load = useCallback(async () => {
    try {
      const res = await api.negotiations();
      setNegotiations(res.negotiations);
    } finally {
      setLoading(false);
    }
  }, []);

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

  const filtered = useMemo(() => {
    return negotiations.filter((n) => {
      const matchStatus = statusFilter === "all" || n.status === statusFilter;
      const matchSearch =
        !search ||
        n.id.toLowerCase().includes(search.toLowerCase()) ||
        (FEATURE_LABELS[n.feature_type] ?? n.feature_type)
          .toLowerCase()
          .includes(search.toLowerCase());
      return matchStatus && matchSearch;
    });
  }, [negotiations, statusFilter, search]);

  const totalPages = Math.max(1, Math.ceil(filtered.length / PAGE_SIZE));
  const paginated = filtered.slice((page - 1) * PAGE_SIZE, page * PAGE_SIZE);

  const getFairness = (n: Negotiation) => {
    const r = (n as any).result;
    if (r?.fairness_score != null) return Math.round(r.fairness_score * 100);
    return null;
  };

  return (
    <div className="flex h-screen w-full overflow-hidden bg-[#020105] text-slate-300 relative">
      <div className="absolute inset-0 bg-grid-subtle opacity-20 pointer-events-none" />
      <Sidebar />

      <main className="flex-1 flex flex-col h-full overflow-hidden relative z-10">
        {/* Top bar */}
        <header className="h-16 flex items-center justify-between px-6 bg-[#050505]/80 backdrop-blur-md border-b border-white/5 sticky top-0 z-30 shrink-0">
          <div>
            <h2 className="text-base font-medium text-white tracking-tight">
              Negotiation History
            </h2>
            <p className="text-[10px] text-slate-600 mt-0.5">
              {filtered.length} record{filtered.length !== 1 ? "s" : ""} found
            </p>
          </div>
          <Link
            href="/"
            className="flex items-center gap-2 px-4 py-2 rounded-lg bg-[#B7A6FB] text-[#020105] text-xs font-bold hover:brightness-110 transition-all"
          >
            <Icon name="add" className="text-sm" />
            New Request
          </Link>
        </header>

        <div className="flex-1 overflow-y-auto p-6">
          {/* Search + Filters */}
          <div className="glass-card rounded-xl p-4 mb-6">
            <div className="relative mb-4">
              <Icon
                name="search"
                className="absolute left-3 top-1/2 -translate-y-1/2 text-slate-500 text-lg"
              />
              <input
                type="text"
                value={search}
                onChange={(e) => { setSearch(e.target.value); setPage(1); }}
                placeholder="Search by ID or feature type..."
                className="w-full bg-white/5 border border-white/10 rounded-lg pl-10 pr-4 py-2.5 text-sm text-white placeholder-slate-600 focus:outline-none focus:border-[#B7A6FB]/40 transition-all"
              />
            </div>
            <div className="flex flex-wrap gap-2">
              {STATUS_FILTERS.map((f) => (
                <button
                  key={f.key}
                  onClick={() => { setStatusFilter(f.key); setPage(1); }}
                  className={`flex items-center gap-2 px-3 py-1.5 rounded-full text-xs font-medium transition-all border ${
                    statusFilter === f.key
                      ? "bg-[#B7A6FB] text-[#020105] border-[#B7A6FB]"
                      : "bg-white/5 text-slate-400 border-white/10 hover:border-[#B7A6FB]/30 hover:text-white"
                  }`}
                >
                  {f.dot && (
                    <span className={`size-1.5 rounded-full ${f.dot}`} />
                  )}
                  {f.label}
                </button>
              ))}
            </div>
          </div>

          {/* Table */}
          {loading ? (
            <div className="flex items-center justify-center h-48 text-slate-600">
              <Icon name="progress_activity" className="animate-spin text-3xl text-[#B7A6FB]" />
            </div>
          ) : paginated.length === 0 ? (
            <div className="flex flex-col items-center justify-center h-48 gap-3 text-slate-600">
              <Icon name="search_off" className="text-4xl" />
              <p className="text-sm">No negotiations match your filters.</p>
            </div>
          ) : (
            <div className="glass-card rounded-xl overflow-hidden">
              <table className="w-full text-sm">
                <thead>
                  <tr className="border-b border-white/5 text-[10px] text-slate-500 uppercase tracking-wider font-mono">
                    <th className="text-left px-5 py-3">Feature</th>
                    <th className="text-left px-5 py-3">Participants</th>
                    <th className="text-left px-5 py-3">Status</th>
                    <th className="text-left px-5 py-3">Fairness</th>
                    <th className="text-left px-5 py-3">Date</th>
                    <th className="text-right px-5 py-3">Actions</th>
                  </tr>
                </thead>
                <tbody>
                  {paginated.map((neg, i) => {
                    const fairness = getFairness(neg);
                    return (
                      <tr
                        key={neg.id}
                        className={`border-b border-white/5 hover:bg-[#B7A6FB]/5 transition-colors group ${
                          i === paginated.length - 1 ? "border-b-0" : ""
                        }`}
                      >
                        {/* Feature */}
                        <td className="px-5 py-3.5">
                          <div className="flex items-center gap-3">
                            <div className="size-8 rounded-lg bg-white/5 border border-white/10 flex items-center justify-center shrink-0">
                              <Icon
                                name={FEATURE_ICONS[neg.feature_type] ?? "hub"}
                                className="text-[#B7A6FB] text-base"
                              />
                            </div>
                            <div>
                              <p className="text-white font-medium text-xs">
                                {FEATURE_LABELS[neg.feature_type] ?? neg.feature_type}
                              </p>
                              <p className="text-[10px] text-slate-600 font-mono">
                                #{neg.id.slice(0, 8)}
                              </p>
                            </div>
                          </div>
                        </td>

                        {/* Participants */}
                        <td className="px-5 py-3.5">
                          <div className="flex -space-x-2">
                            {[...Array(Math.min(neg.participant_count ?? 0, 3))].map((_, j) => (
                              <div
                                key={j}
                                className="w-6 h-6 rounded-full bg-slate-800 border border-black flex items-center justify-center text-[8px] text-white ring-1 ring-white/10"
                              >
                                {String.fromCharCode(65 + j)}
                              </div>
                            ))}
                          </div>
                        </td>

                        {/* Status */}
                        <td className="px-5 py-3.5">
                          <span
                            className={`text-[10px] font-bold uppercase tracking-wide px-2 py-0.5 rounded border ${
                              STATUS_BADGE[neg.status] ?? "text-slate-400 bg-white/5 border-white/10"
                            }`}
                          >
                            {STATUS_LABELS[neg.status] ?? neg.status}
                          </span>
                        </td>

                        {/* Fairness */}
                        <td className="px-5 py-3.5">
                          {fairness != null ? (
                            <div className="flex items-center gap-2">
                              <div className="w-20 h-1 bg-white/10 rounded-full overflow-hidden">
                                <div
                                  className="h-full bg-[#B7A6FB] rounded-full"
                                  style={{ width: `${fairness}%` }}
                                />
                              </div>
                              <span className="text-[10px] text-slate-400 font-mono">
                                {fairness}%
                              </span>
                            </div>
                          ) : (
                            <span className="text-[10px] text-slate-600 font-mono">—</span>
                          )}
                        </td>

                        {/* Date */}
                        <td className="px-5 py-3.5">
                          <span className="text-[10px] text-slate-500 font-mono">
                            {relativeTime(neg.created_at)}
                          </span>
                        </td>

                        {/* Actions */}
                        <td className="px-5 py-3.5 text-right">
                          <Link
                            href={`/negotiation/${neg.id}`}
                            className="inline-flex items-center justify-center size-8 rounded-lg bg-white/5 border border-white/10 text-slate-500 hover:text-[#B7A6FB] hover:border-[#B7A6FB]/30 transition-all"
                            title="View details"
                          >
                            <Icon name="visibility" className="text-base" />
                          </Link>
                        </td>
                      </tr>
                    );
                  })}
                </tbody>
              </table>

              {/* Pagination */}
              <div className="flex items-center justify-between px-5 py-3 border-t border-white/5 text-[10px] text-slate-500 font-mono">
                <span>
                  Showing {Math.min((page - 1) * PAGE_SIZE + 1, filtered.length)}–
                  {Math.min(page * PAGE_SIZE, filtered.length)} of {filtered.length} negotiations
                </span>
                <div className="flex items-center gap-1">
                  <button
                    onClick={() => setPage((p) => Math.max(1, p - 1))}
                    disabled={page === 1}
                    className="size-7 rounded flex items-center justify-center bg-white/5 border border-white/10 hover:border-[#B7A6FB]/30 hover:text-[#B7A6FB] disabled:opacity-30 disabled:cursor-not-allowed transition-all"
                  >
                    <Icon name="chevron_left" className="text-sm" />
                  </button>
                  <button
                    onClick={() => setPage((p) => Math.min(totalPages, p + 1))}
                    disabled={page === totalPages}
                    className="size-7 rounded flex items-center justify-center bg-white/5 border border-white/10 hover:border-[#B7A6FB]/30 hover:text-[#B7A6FB] disabled:opacity-30 disabled:cursor-not-allowed transition-all"
                  >
                    <Icon name="chevron_right" className="text-sm" />
                  </button>
                </div>
              </div>
            </div>
          )}
        </div>
      </main>
    </div>
  );
}