'use client';

import { useEffect, useRef, useState } from 'react';
import type { GeoJsonFeatureCollection } from '@/lib/airports';
import type { PlaneState, StateSnapshot } from '@/lib/game/state';
import { PLANE_TYPES } from '@/lib/game/catalog';
import { abandonPenalty } from '@/lib/game/penalty';
import { formatCash, formatDeadlineRelative, formatFuel, formatKm, formatSimClock, formatSpecialLabel } from '@/lib/format';
import { useGameAction } from '@/lib/useGameAction';
import { useSimClock } from '@/lib/useSimClock';
import { cargoWeightFor } from './RightPane';
import type { HoverTarget } from './hoverTypes';

interface LeftPaneProps {
  state: StateSnapshot | null;
  loading: boolean;
  error: string | null;
  // ISS-021 (v0.20.0): push the full snapshot returned by an action endpoint into the shared shell
  // state — needed now that the per-plane cargo rows' fly/abandon actions live in this pane.
  applySnapshot: (snapshot: StateSnapshot) => void;
  // ISS-002 (v0.15.0): report fleet-row hovers to the shell so the map can highlight the plane.
  onHover: (target: HoverTarget | null) => void;
  // ISS-008 (v0.17.0): report a failed sim-control POST to the shell as an error toast.
  onError?: (message: string) => void;
}

// Flying planes show their current leg from the snapshot's dest fields (v0.12.0).
function planeLocation(p: PlaneState): string {
  if (p.status === 'flying' && p.destName) return `${p.locationName} → ${p.destName}`;
  return p.locationName;
}

// Cargo loadout "X.Xt / Y.Yt" (v0.27.0) — used/max payload in tonnes, one decimal;
// expired packages still occupy their payload.
function loadoutFor(state: StateSnapshot, p: PlaneState): string {
  const used = cargoWeightFor(state, p.id);
  const maxPayloadKg = state.catalog.find((e) => e.model === p.model)?.maxPayloadKg ?? PLANE_TYPES[p.model]?.maxPayloadKg ?? 0;
  return `${(used / 1000).toFixed(1)}t / ${(maxPayloadKg / 1000).toFixed(1)}t`;
}

export default function LeftPane({ state, loading, error, applySnapshot, onHover, onError }: LeftPaneProps) {
  // ISS-021 (v0.20.0): shared action runner for the per-plane cargo/queue actions (moved here from RightPane).
  const { runAction, busy: actionsBusy, actionError } = useGameAction(state, applySnapshot, onError);

  // ISS-023 (v0.21.0): Relocate selections — moved here from the right-pane market row; same
  // "effective selection" pattern as there: the user's pick while it stays valid, else a sensible
  // default (first grounded plane / first airport).
  const [relocatePlaneId, setRelocatePlaneId] = useState<string | null>(null);
  const [relocateDestIcao, setRelocateDestIcao] = useState<string | null>(null);

  // ISS-010 (v0.18.0): one-time /api/airports fetch per page life — destination options for the
  // Relocate section, sorted by name so e2e selection is stable. Same promise-ref pattern as Map.tsx;
  // on failure airportOptions stays null and the Relocate button simply remains disabled. Moved here
  // from RightPane in ISS-023 (v0.21.0) — the relocate-dest select was its only consumer there.
  const [airportOptions, setAirportOptions] = useState<Array<{ name: string; icao: string }> | null>(null);
  const airportsPromiseRef = useRef<Promise<Array<{ name: string; icao: string }>> | null>(null);
  useEffect(() => {
    if (!airportsPromiseRef.current) {
      airportsPromiseRef.current = fetch('/api/airports', { cache: 'no-store' })
        .then((res) => {
          if (!res.ok) throw new Error(`GET /api/airports → HTTP ${res.status}`);
          return res.json() as Promise<GeoJsonFeatureCollection>;
        })
        .then((fc) =>
          fc.features
            .map((f) => ({ name: f.properties.name, icao: f.properties.icao }))
            .sort((a, b) => a.name.localeCompare(b.name, 'en')),
        );
    }
    void airportsPromiseRef.current.then(setAirportOptions).catch(() => {});
  }, []);

  // Snapshot clock — feeds the deadline/penalty previews in the per-plane cargo rows.
  const clockMs = state?.simState.clockMs ?? 0;

  // ISS-023 (v0.21.0): Relocate — any plane can be repositioned to any airport via the existing fly
  // endpoint (pure repositioning, no package needed since v0.12.0). Moved here from the right-pane
  // market row; with state null both fall back to null and the section isn't rendered.
  // ISS-053 (v0.32.0): widened from grounded-only to ALL planes — a flying plane's relocation is
  // queued instead of started immediately (see relocate-go below).
  const relocatable = state ? state.planes : [];
  const relocatePlane = relocatable.find((p) => p.id === relocatePlaneId) ?? relocatable[0] ?? null;
  const relocateDest =
    airportOptions === null ? null : airportOptions.find((a) => a.icao === relocateDestIcao) ?? airportOptions[0] ?? null;
  // ISS-077 (v0.41.0): while flying, the Relocate click would POST /queue — block it when the selected
  // destination is already active or queued (the server rejects that with 409). Grounded planes are unaffected.
  const relocateBlocked =
    relocatePlane?.status === 'flying' && relocateDest !== null &&
    (relocatePlane.destIcao === relocateDest.icao || relocatePlane.queue.includes(relocateDest.icao));

  // ISS-008: browser-notification opt-in. Starts null (SSR-safe — the real permission is read
  // in an effect after hydration, so server and client render identically) and follows the
  // result of Notification.requestPermission(). 'unsupported' = no Notification API at all.
  const [notifPermission, setNotifPermission] = useState<string | null>(null);
  useEffect(() => {
    if ('Notification' in window) setNotifPermission(Notification.permission);
    else setNotifPermission('unsupported');
  }, []);

  // null (pre-effect) and 'default' both read as the opt-in prompt.
  const notifLabel: string =
    notifPermission === 'granted'
      ? 'Notifications enabled'
      : notifPermission === 'denied'
        ? 'Notifications blocked'
        : notifPermission === 'unsupported'
          ? 'Notifications unavailable'
          : 'Enable notifications';

  // ISS-007: the clock ticks client-side between polls at the fixed world rate, re-syncing to
  // server truth on every snapshot (and freezing while nothing is happening). Only the sim-clock
  // paragraph uses this — deadline and penalty previews stay snapshot-based (deterministic against
  // the server clock).
  const simClockMs = useSimClock(state);

  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) => {
                  // ISS-054 (v0.33.0): the merged per-plane block — status/fuel/loadout plus the former
                  // On board section's cargo rows and queue legs, so all plane info lives in one place.
                  const cargo = state.packages.filter(
                    (pkg) => pkg.planeId === p.id && (pkg.status === 'loaded' || pkg.status === 'expired'),
                  );
                  return (
                    // ISS-002: hovering a fleet row highlights the plane on the map. Handlers live only on
                    // the outer <li> — React's enter/leave don't fire when moving to a child, so this covers
                    // the whole block without flicker between sub-elements; cargo rows override with their
                    // own package hover (below).
                    <li
                      key={p.id}
                      data-testid={`plane-${p.id}`}
                      className="plane-row"
                      onMouseEnter={() => onHover({ kind: 'plane', id: p.id })}
                      onMouseLeave={() => onHover(null)}
                    >
                      <div className="plane-main">
                        <span className="plane-model">{PLANE_TYPES[p.model]?.name ?? p.model}</span>
                        {p.status === 'flying' ? (
                          <>
                            <span className="plane-status status-flying">in flight</span>
                            {p.destName && (
                              <span data-testid={`plane-leg-${p.id}`} className="contract-route">
                                {p.locationName} → {p.destName}
                              </span>
                            )}
                          </>
                        ) : (
                          <>
                            <span className="plane-status status-available">{p.locationIcao}</span>
                            {/* v0.39.0 (ISS-069): maintenance pills — "in repair" while the gate runs, "broken" at zero health. */}
                            {p.status === 'repairing' && (
                              <span data-testid={`plane-repairing-${p.id}`} className="plane-status status-repairing">in repair</span>
                            )}
                            {p.health <= 0 && (
                              <span data-testid={`plane-broken-${p.id}`} className="plane-status status-broken">broken</span>
                            )}
                          </>
                        )}
                      </div>
                      <div className="fuel-bar" aria-hidden="true">
                        <div style={{ width: `${Math.max(0, Math.min(100, (p.fuel / p.maxFuel) * 100))}%` }} />
                      </div>
                      {/* v0.39.0 (ISS-069): health bar — sibling of the fuel bar, amber fill. */}
                      <div className="health-bar" aria-hidden="true">
                        <div style={{ width: `${Math.max(0, Math.min(100, p.health))}%` }} />
                      </div>
                      <div className="plane-sub">
                        <span data-testid={`plane-fuel-${p.id}`}>{formatFuel(p.fuel, p.maxFuel)}</span>
                        {/* v0.39.0 (ISS-069): health percentage next to the fuel readout. */}
                        <span data-testid={`plane-health-${p.id}`}>{Math.round(p.health)}%</span>
                        <span data-testid={`plane-loadout-${p.id}`}>{loadoutFor(state, p)}</span>
                        <span className="plane-loc">{planeLocation(p)}</span>
                      </div>
                      {/* v0.39.0 (ISS-069): repair — grounded plane with worn health; flat cost is server-side only (no preview). */}
                      {p.status === 'available' && p.health < 100 && (
                        <button
                          type="button"
                          data-testid={`repair-${p.id}`}
                          className="pane-btn repair-btn"
                          disabled={actionsBusy}
                          onClick={() => void runAction(`/api/planes/${p.id}/repair`)}
                        >
                          Repair
                        </button>
                      )}
                      {cargo.map((pkg) => {
                        const penalty = abandonPenalty(pkg, clockMs);
                        // ISS-077 (v0.41.0): while flying the click would POST /queue — disable it when the
                        // destination is already active or queued (the server rejects that with 409). Grounded
                        // clicks go to /fly, which has no such conflict.
                        const alreadyQueued = p.status === 'flying' && (p.destIcao === pkg.destIcao || p.queue.includes(pkg.destIcao));
                        return (
                          // ISS-025 (v0.22.0): hovering a loaded package draws its full origin→dest trace on the map —
                          // same as job-list rows — and keeps this plane's halo lit via planeId. Leaving the row restores
                          // the block's plain plane highlight; leaving the whole block still ends at null (the child's
                          // mouseleave fires before the parent's).
                          <div
                            key={pkg.id}
                            data-testid={`onboard-package-${pkg.id}`}
                            className="contract-row"
                            onMouseEnter={() => onHover({ kind: 'package', originIcao: pkg.originIcao, destIcao: pkg.destIcao, planeId: p.id })}
                            onMouseLeave={() => onHover({ kind: 'plane', id: p.id })}
                          >
                            <button
                              type="button"
                              data-testid={`fly-to-${pkg.id}`}
                              className="pane-btn onboard-fly-btn"
                              disabled={actionsBusy || alreadyQueued}
                              title={alreadyQueued ? 'Already in flight queue' : undefined}
                              // ISS-053 (v0.32.0): a flying plane can't start another leg — the click queues it instead,
                              // so "Fly to …" works from any state and the queue needs no dedicated input.
                              onClick={() => void runAction(`/api/planes/${p.id}/${p.status === 'flying' ? 'queue' : 'fly'}`, { destIcao: pkg.destIcao })}
                            >
                              {/* ISS-081 (v0.40.0): ICAO tags instead of full airport names. */}
                              <span className="onboard-fly-label" title={`Fly to ${pkg.destIcao}`}>
                                Fly to {pkg.destIcao}
                              </span>
                            </button>
                            {/* ISS-082 (v0.42.0): the per-leg Refuel button is gone — dispatch auto-refuels. */}
                            <div className="onboard-actions">
                              <button
                                type="button"
                                data-testid={`abandon-${pkg.id}`}
                                className="pane-btn"
                                disabled={actionsBusy || p.status !== 'available'}
                                onClick={() => void runAction(`/api/packages/${pkg.id}/abandon`)}
                              >
                                Abandon{' '}
                                <span data-testid={`abandon-penalty-${pkg.id}`}>−{formatCash(penalty)}</span>
                              </button>
                            </div>
                            <div className="contract-sub">
                              {/* ISS-081 (v0.40.0): ICAO tags instead of full airport names. */}
                              <span data-testid={`onboard-route-${pkg.id}`} className="contract-route">
                                {pkg.originIcao} → {pkg.destIcao}
                              </span>
                              {/* v0.48.0 (ISS-095): leg distance after the route, e.g. "EGCC → GMME 554km". */}
                              <span data-testid={`onboard-distance-${pkg.id}`}>{formatKm(pkg.distanceKm)}</span>
                              {/* v0.37.0 (ISS-073): special-status badge — rendered only when the package has one. */}
                              {pkg.special && (
                                <span data-testid={`package-special-${pkg.id}`} className="special-badge">
                                  {formatSpecialLabel(pkg.special)}
                                </span>
                              )}
                              <span>{formatCash(pkg.reward)}</span>
                              {pkg.status === 'expired' ? (
                                <span data-testid={`onboard-expired-${pkg.id}`}>expired</span>
                              ) : (
                                <span>{formatDeadlineRelative(pkg.deadlineSimTime, clockMs)}</span>
                              )}
                            </div>
                          </div>
                        );
                      })}
                      {/* ISS-043 (v0.26.0): flight queue — the not-yet-started legs with cancel.
                          ISS-053 (v0.32.0): the dedicated add input is gone — fly-to and Relocate post to
                          /queue while a plane is flying, so no separate entry point is needed.
                          ISS-054 (v0.33.0): rendered only when non-empty. */}
                      {p.queue.length > 0 && (
                        <div className="queue-subsection">
                          <span className="queue-heading">Queue</span>
                          {/* ISS-055 (v0.31.0): testids scoped by plane id — with two blocks the unscoped ids
                              duplicated in the DOM and broke Playwright strict mode. */}
                          {p.queue.map((icao, i) => (
                            <div key={`${icao}-${i}`} data-testid={`queue-leg-${p.id}-${i}`} className="queue-row">
                              <span className="contract-route">
                                {airportOptions?.find((a) => a.icao === icao)?.name ?? icao} ({icao})
                              </span>
                              <button
                                type="button"
                                data-testid={`queue-cancel-${p.id}-${i}`}
                                className="pane-btn"
                                disabled={actionsBusy}
                                onClick={() => void runAction(`/api/planes/${p.id}/queue/cancel`, { index: i })}
                              >
                                Cancel
                              </button>
                            </div>
                          ))}
                        </div>
                      )}
                    </li>
                  );
                })}
              </ul>
            )}
          </section>

          {/* ISS-023 (v0.21.0): moved here from the right-pane market row — it belongs with
              everything else about our planes, between Fleet and Time. */}
          {/* ISS-027 (v0.22.0): hovering the section previews the planned relocation on the map —
              dashed trace from the selected plane's airport to the destination + a ring on the target.
              With no planes or no loaded airport options there is nothing to preview → null. */}
          <section
            className="pane-section"
            data-testid="relocate-section"
            onMouseEnter={() =>
              onHover(
                relocatePlane && relocateDest
                  ? { kind: 'route', fromIcao: relocatePlane.locationIcao, toIcao: relocateDest.icao }
                  : null,
              )
            }
            onMouseLeave={() => onHover(null)}
          >
            <h3 className="pane-heading">Relocate</h3>
            {/* ISS-010 (v0.18.0): relocate a plane — the fly endpoint already allows pure
                repositioning, this row just exposes it for planes with nothing on board.
                ISS-053 (v0.32.0): lists ALL planes; a flying one's relocation is queued below. */}
            <div className="market-row market-row-relocate">
              <select
                data-testid="relocate-plane"
                aria-label="Plane to relocate"
                value={relocatePlane?.id ?? ''}
                onChange={(e) => setRelocatePlaneId(e.target.value || null)}
              >
                {relocatable.map((p) => (
                  <option key={p.id} value={p.id}>
                    {PLANE_TYPES[p.model]?.name ?? p.model} — {p.locationIcao}
                  </option>
                ))}
              </select>
              <select
                data-testid="relocate-dest"
                aria-label="Relocation destination airport"
                value={relocateDest?.icao ?? ''}
                onChange={(e) => setRelocateDestIcao(e.target.value || null)}
              >
                {airportOptions?.map((a) => (
                  // ISS-077 (v0.41.0): a flying plane's active/queued airports can't be re-selected — the
                  // server would reject them with 409; native disabled options, no text change.
                  <option key={a.icao} value={a.icao} disabled={relocatePlane?.status === 'flying' && (relocatePlane.destIcao === a.icao || relocatePlane.queue.includes(a.icao))}>
                    {a.name}
                  </option>
                ))}
              </select>
              <button
                type="button"
                data-testid="relocate-go"
                className="pane-btn"
                disabled={actionsBusy || relocatePlane === null || relocateDest === null || relocateBlocked}
                // ISS-053 (v0.32.0): a flying plane can't start another leg — queue it instead, so the
                // relocation takes off when the current one lands.
                onClick={() => {
                  if (relocatePlane && relocateDest) {
                    void runAction(`/api/planes/${relocatePlane.id}/${relocatePlane.status === 'flying' ? 'queue' : 'fly'}`, { destIcao: relocateDest.icao });
                  }
                }}
              >
                Relocate
              </button>
            </div>
          </section>

          {/* ISS-082 (v0.42.0): the "Refuel to full" section is gone — dispatch auto-refuels instead. */}

          <section className="pane-section">
            <h3 className="pane-heading">Time</h3>
            {/* ISS-117 (v0.52.0): no player-facing time controls — the world runs at a fixed rate;
                only the clock display remains here. */}
            <p data-testid="sim-clock" className="sim-clock">{simClockMs !== null && formatSimClock(simClockMs)}</p>
            {/* ISS-008: explicit opt-in for browser notifications (fired when the window is hidden). */}
            <button
              type="button"
              data-testid="enable-notifications"
              className="notif-toggle"
              disabled={notifPermission === 'unsupported'}
              title={notifPermission === 'unsupported' ? 'This browser does not support notifications' : undefined}
              onClick={() => {
                // A rejection (rare — e.g. some headless setups) reads as "blocked".
                if ('Notification' in window) {
                  void Notification.requestPermission()
                    .then(setNotifPermission)
                    .catch(() => setNotifPermission('denied'));
                }
              }}
            >
              {notifLabel}
            </button>
          </section>

          {error && (
            <p data-testid="left-error" className="pane-error">
              {error}
            </p>
          )}
          {/* ISS-021 (v0.20.0): inline error from a failed On board action — mirrors right-error. */}
          {actionError && <p data-testid="left-action-error" className="pane-error">{actionError}</p>}
        </>
      ) : null}
    </aside>
  );
}