'use client';

import { useState, type ChangeEvent } from 'react';
import type { ContractState, PlaneState, StateSnapshot } from '@/lib/game/state';
import { PLANE_TYPES } from '@/lib/game/catalog';
import { formatCash, formatFuel, formatSimClock } from '@/lib/format';

interface LeftPaneProps {
  state: StateSnapshot | null;
  loading: boolean;
  error: string | null;
  // The shell's single-poll refresh — called after a sim-control POST so the pane updates immediately.
  onRefresh: () => void;
}

const SCALE_OPTIONS = Array.from({ length: 60 }, (_, i) => i + 1); // 1x–60x, matching POST /api/sim's clamp range

function planeLocation(p: PlaneState, contracts: ContractState[]): string {
  if (p.status === 'flying' && p.contractId) {
    const c = contracts.find((c) => c.id === p.contractId);
    if (c) return `${p.locationName} → ${c.destName}`;
  }
  return p.locationName;
}

export default function LeftPane({ state, loading, error, onRefresh }: LeftPaneProps) {
  const [busy, setBusy] = useState(false);

  // POST /api/sim, then refetch the full snapshot immediately so the pane reflects the new
  // controls without waiting for the next poll tick. On failure keep the stale UI — the
  // running poll retries on its own and surfaces the error state.
  const applySimControls = async (body: { timeScale?: number; paused?: boolean }) => {
    if (busy) return;
    setBusy(true);
    try {
      const res = await fetch('/api/sim', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(body),
        cache: 'no-store',
      });
      if (!res.ok) throw new Error(`POST /api/sim → HTTP ${res.status}`);
      onRefresh();
    } catch (err) {
      console.error('failed to apply sim controls', err);
    } finally {
      setBusy(false);
    }
  };

  const paused = state?.simState.paused ?? false;
  const timeScale = state?.simState.timeScale ?? 1;

  return (
    <aside data-testid="left-pane" className="pane left-pane">
      <h2 className="pane-title">Assets</h2>
      {loading && !state ? (
        <p data-testid="left-loading" className="pane-muted">Loading…</p>
      ) : state ? (
        <>
          <section className="pane-section">
            <div className="stat-row">
              <span>Cash</span>
              <strong data-testid="wallet-cash">{formatCash(state.account.cash)}</strong>
            </div>
            <div className="stat-row">
              <span>Reputation</span>
              <strong data-testid="reputation">{state.account.reputation}</strong>
            </div>
          </section>

          <section className="pane-section">
            <h3 className="pane-heading">Fleet</h3>
            {state.planes.length === 0 ? (
              <p className="pane-muted">No planes.</p>
            ) : (
              <ul data-testid="fleet-list" className="fleet-list">
                {state.planes.map((p) => (
                  <li key={p.id} data-testid={`plane-${p.id}`} className="plane-row">
                    <div className="plane-main">
                      <span className="plane-model">{PLANE_TYPES[p.model]?.name ?? p.model}</span>
                      <span className={`plane-status status-${p.status}`}>{p.status}</span>
                    </div>
                    <div className="fuel-bar" aria-hidden="true">
                      <div style={{ width: `${Math.max(0, Math.min(100, (p.fuel / p.maxFuel) * 100))}%` }} />
                    </div>
                    <div className="plane-sub">
                      <span data-testid={`plane-fuel-${p.id}`}>{formatFuel(p.fuel, p.maxFuel)}</span>
                      <span className="plane-loc">{planeLocation(p, state.contracts)}</span>
                    </div>
                  </li>
                ))}
              </ul>
            )}
          </section>

          <section className="pane-section">
            <h3 className="pane-heading">Time</h3>
            <p data-testid="sim-clock" className="sim-clock">
              {formatSimClock(state.simState.clockMs)}
              {paused ? ' (paused)' : ''}
            </p>
            <div className="time-controls">
              <button
                type="button"
                data-testid="pause-toggle"
                disabled={busy}
                onClick={() => void applySimControls({ paused: !paused })}
              >
                {paused ? 'Resume' : 'Pause'}
              </button>
              <select
                data-testid="time-scale-select"
                aria-label="Time scale"
                value={String(timeScale)}
                disabled={busy}
                onChange={(e: ChangeEvent<HTMLSelectElement>) => void applySimControls({ timeScale: Number(e.target.value) })}
              >
                {SCALE_OPTIONS.map((n) => (
                  <option key={n} value={n}>
                    {n}x
                  </option>
                ))}
              </select>
            </div>
          </section>

          {error && (
            <p data-testid="left-error" className="pane-error">
              {error}
            </p>
          )}
        </>
      ) : null}
    </aside>
  );
}