import Phaser from '../vendor/phaser.js';
import { config } from '../config/Config.js';
import { toColor, toCss } from '../utils/Color.js';
import { fontStack, themeColor } from '../utils/Theme.js';
import { Rng } from '../utils/Rng.js';
import { Galaxy } from '../galaxy/Galaxy.js';
import { formatSystemReport } from '../galaxy/SystemReport.js';
import { Discovery } from '../galaxy/Discovery.js';
import { Ship } from '../entities/Ship.js';
import { Planet } from '../entities/Planet.js';
import { Starfield } from '../visuals/Starfield.js';
import { DiscoveryCompass, circleInView } from '../ui/DiscoveryCompass.js';
import { ActionBar } from '../ui/ActionBar.js';

const FONT_FALLBACK = "'Segoe UI', 'Helvetica Neue', Arial, sans-serif";
const HEADER_FONT = () => fontStack('header', FONT_FALLBACK);
const BODY_FONT = () => fontStack('body', FONT_FALLBACK);

/**
 * The game world (v0.3: the current system — the player's home world at the
 * origin plus the system's other worlds scattered around it, in open space).
 * Click anywhere to fly there.
 *
 * Discovery: come within discovery distance (data/game.json) of a world's
 * edge and it is DISCOVERED (state in this.discovery). Discovered worlds
 * that are off-screen get a themed compass arrow on the screen edge
 * (this.compass) pointing the way back — so the player always has a
 * reference to found worlds while exploring the rest of the system.
 */
export class GameScene extends Phaser.Scene {
  constructor() {
    super({ key: 'GameScene' });
  }

  preload() {
    // The planet spritesheet: frameWidth×frameHeight frames; the first
    // frames are Terran worlds (see data/planets.json → frames).
    this.load.spritesheet(
      Planet.TEXTURE_KEY,
      config.get('planets.texture', 'assets/images/planets.png'),
      {
        frameWidth: config.get('planets.frameWidth', 1024),
        frameHeight: config.get('planets.frameHeight', 1024),
      },
    );
  }

  create() {
    // Camera: smoothly follows the ship (updateCamera below). This motion
    // is what drives the parallax starfield — ship flies, view trails.
    this.cameraFollowShip = config.get('game.camera.followShip', true);
    this.cameraFollowRate = config.get('game.camera.followRate', 3.0); // 1/s

    // We are, after all, in a system. Establish the galaxy (shared
    // registry), the current system record, and its lazy contents — the
    // dossier below and the world's other planets both read them.
    this.ensureGalaxy();
    this.systemRecord = this.galaxy.currentSystem();
    this.systemContent = this.galaxy.ensureContent(this.systemRecord.id);
    this.createSystemHud();

    // The home planet — the player's Terran world, always present in the
    // system they start in. It sits at the world origin. Which Terran face
    // it shows is a seed-deterministic pick from the terran pool, so the
    // same galaxy always yields the same home world.
    const homeName = config.get('planets.homePlanet', 'terran');
    const homeRng = Rng.derive(this.galaxy.seed, 'planet', 'home');
    this.planet = new Planet(this, 0, 0, Planet.frameFor(homeName, homeRng), homeName);
    this.planet.setDepth(5); // above the starfield (depths 0–2), below the ship (10)

    // The rest of the solar system — the generated worlds, placed by the
    // generator (data/planets.json → solarSystem) in a band around the home
    // world. Same solid-disc rules as home: fly close, never through.
    this.systemPlanets = [];
    if (config.get('planets.solarSystem.enabled', true)) {
      for (const rec of this.systemContent.planets ?? []) {
        if (typeof rec.x !== 'number' || typeof rec.y !== 'number') continue;
        const kind = rec.class || 'rocky';
        const frame = Planet.frameFor(kind, Rng.derive(this.galaxy.seed, 'planet', rec.name));
        const tint = config.get(`planets.classTint.${kind}`);
        const p = new Planet(this, rec.x, rec.y, frame, kind, {
          scale: rec.scale ?? 1,
          tint: tint === undefined ? undefined : toColor(tint),
        });
        p.setDepth(5);
        p.discoveryId = rec.name; // unique within the system
        p.discoveryName = rec.name;
        this.systemPlanets.push(p);
      }
    }
    this.solidPlanets = [this.planet, ...this.systemPlanets];

    // The ship — a short hop (~150 px, edge-to-edge) from the home world's
    // rim, in a seed-derived direction: same galaxy ⇒ same start.
    this.ship = new Ship(this, 0, 0);
    this.ship.setDepth(10);
    const spawn = this.planet.edgePoint(
      Rng.derive(this.galaxy.seed, 'spawn', 'ship').range(0, Math.PI * 2),
      config.get('planets.spawnDistanceFromEdge', 150),
      this.ship.radius,
    );
    this.ship.setPosition(spawn.x, spawn.y);

    // Center the camera on the ship from the very first frame.
    this.cameras.main.setScroll(
      this.ship.x - this.scale.width / 2,
      this.ship.y - this.scale.height / 2,
    );

    // Background (stars are placed around the current camera view).
    this.starfield = new Starfield(this);
    this.starfield.create();

    // Discovery: which objects the player has found (within discovery
    // distance of an edge — data/game.json), tracked per system. Kept in
    // the shared registry so it survives scene restarts; serializable for
    // saves later (Discovery.toJSON). The compass turns the discovered set
    // into screen-edge arrows for the objects currently out of sight.
    this.discovery = this.registry.get('discovery') ?? null;
    if (!this.discovery) {
      this.discovery = new Discovery(config.get('game.discovery.distance', 540));
      this.registry.set('discovery', this.discovery);
    }
    this.compass = new DiscoveryCompass(this);

    // The command deck — the cyberpunk action bar across the bottom of the
    // screen (config: data/actionbar.json). Six evenly spaced slots:
    // Research, Build, Ship, two reserved, Menu. The slots are the seams
    // for the player's loop — research (time-based, one at a time, see
    // data/research.json) and building (credits + minerals, see
    // data/builds.json) — whose behavior and panels come next.
    this.actionBar =
      config.get('actionbar.enabled', true) === true
        ? new ActionBar(this, {
            onAction: (id) => {
              // TODO(command deck): 'research' → research panel, 'build' → build
              // panel, 'ship' → ship screen, 'menu' → main menu.
              console.info(`[orbit] command deck: ${id}`);
            },
          })
        : null;

    // Hint (pinned just ABOVE the command deck, not under it)
    const deckRoom = this.actionBar
      ? config.get('actionbar.height', 92) + config.get('actionbar.margin.bottom', 12)
      : 0;
    this.hint = this.add
      .text(this.scale.width / 2, this.scale.height - deckRoom - (deckRoom ? 20 : 26), config.get('game.hintText', ''), {
        fontFamily: BODY_FONT(),
        fontSize: '14px',
        color: '#54608a',
        letterSpacing: 1,
      })
      .setOrigin(0.5)
      .setScrollFactor(0); // UI: pinned to the screen, not the world

    // Input: click = fly there (a click ON the command deck is deck
    // business, not flight). A click inside a planet clamps to that
    // planet's keep-out rim — the ship can stop at the clearance, never
    // inside. (Worlds don't overlap, so sequential clamping is exact.)
    this.input.on('pointerdown', (pointer) => {
      if (this.actionBar && this.actionBar.contains(pointer.x, pointer.y)) return;
      let aim = { x: pointer.worldX, y: pointer.worldY };
      for (const p of this.solidPlanets) {
        aim = p.aimPoint(aim.x, aim.y, this.ship.radius);
      }
      this.showTargetMarker(aim.x, aim.y);
      this.ship.setTarget(aim.x, aim.y);
      this.hideHint();
    });
  }

  /**
   * The galaxy comes from the shared registry (built by the menu from the
   * chosen seed). Dev boots that skip the menu (dev/test-game.html) get a
   * fresh dev galaxy so the scene always works standalone.
   */
  ensureGalaxy() {
    this.galaxy = this.registry.get('galaxy') ?? null;
    if (!this.galaxy) {
      const seed = Rng.randomSeedString(8);
      this.galaxy = Galaxy.create(seed);
      this.registry.set('galaxy', this.galaxy);
      this.registry.set('seed', seed);
      console.warn(`[orbit] no galaxy in the registry — generated a dev galaxy (seed "${seed}")`);
    }
  }

  /**
   * Top-left HUD: the current system's dossier — name, identity, and what
   *'s ALREADY THERE: colonies, mining stations, cloud bases, stations adrift
   * in open space (or "charted · unclaimed" when nobody's settled here).
   * Formatted by the pure SystemReport helper; this method only renders.
   *
   * The system's CONTENTS were ensured in create() (ensureGalaxy +
   * ensureContent) — the first touch of the lazy level-2 generation.
   * (Roster/positions were fixed at the menu's New Game click; this is
   * just the "build the room" part.)
   */
  createSystemHud() {
    const report = formatSystemReport(this.systemContent);
    const fam = BODY_FONT();
    const famHeader = HEADER_FONT();
    const current = this.systemRecord;

    let y = 14;
    const line = (text, style) => {
      this.add
        .text(16, y, text, style)
        .setOrigin(0, 0)
        .setScrollFactor(0) // UI: pinned to the screen, not the world
        .setDepth(30);
      y += 20 + (style.fontSize === '17px' ? 6 : 0);
    };

    line(report.title, {
      fontFamily: famHeader,
      fontSize: '17px',
      // v4 quirk: text colors must be CSS strings (see toCss, utils/Color.js).
      color: toCss(this.galaxy.typeDefs?.[current.type]?.theme?.color ?? '#9fb4e8'),
      letterSpacing: 2,
    });
    line(report.subtitle, { fontFamily: fam, fontSize: '12px', color: '#8fa0c9', letterSpacing: 1 });
    y += 2;
    for (const s of report.settlements) {
      line(s.text, { fontFamily: fam, fontSize: '13px', color: toCss(s.color, '#8fa0c9') });
    }
    line(report.summary, { fontFamily: fam, fontSize: '12px', color: '#54608a' });
    line(`seed ${this.galaxy.seed}`, { fontFamily: fam, fontSize: '11px', color: '#3d476b' });
  }

  update(_time, delta) {
    // Phaser v4 (Giedi): the engine does not step the scene's TimeClock or
    // TweenManager — drive them here or delayedCall/addEvent/tweens never
    // fire. (Same quirk as MenuScene.update; verified Sept 2026.)
    this.time.update(_time, delta);
    this.tweens.update();
    this.ship.update(_time, delta);
    // Every world in the system is solid: the ship may come within the
    // clearance in data/planets.json of a rim, but never closer (or
    // through it).
    for (const p of this.solidPlanets) {
      p.constrainShip(this.ship, this.ship.radius);
    }
    this.updateCamera(delta);
    this.starfield.update(); // after the camera, so it sees this frame's motion
    this.actionBar?.update(_time, delta); // the deck's living details
    this.updateDiscovery(_time, delta); // last: sees this frame's final camera view
  }

  /**
   * The camera chases the ship with a frame-rate-independent ease:
   *   scroll += (shipCenter - scroll) * (1 - e^(-rate·dt))
   * While the ship flies, the camera trails it and the starfield streams
   * past in the opposite direction (real parallax). When the ship stops,
   * the camera keeps easing until it is centered on the ship again — a
   * slow recenter (≈1.5 s at followRate 3) with the stars parallaxing
   * along for the ride.
   */
  updateCamera(delta) {
    if (!this.cameraFollowShip || !this.ship) return;
    const rate = this.cameraFollowRate;
    if (!(rate > 0)) return;

    const cam = this.cameras.main;
    const k = 1 - Math.exp(-rate * (Math.min(delta, 64) / 1000));
    cam.setScroll(
      Phaser.Math.Linear(cam.scrollX, this.ship.x - this.scale.width / 2, k),
      Phaser.Math.Linear(cam.scrollY, this.ship.y - this.scale.height / 2, k),
    );
  }

  /**
   * Discovery, every frame (a handful of distance tests — cheap):
   *   1. Ship within discovery distance of a world's edge → DISCOVERED
   *      (once — state lives in this.discovery), with a rim ping + toast.
   *   2. Discovered worlds that are off-screen feed the compass, which
   *      draws the themed screen-edge arrows pointing back to them.
   */
  updateDiscovery(time, delta) {
    const objects = this.discoverableObjects();
    const sysId = this.systemRecord.id;

    const fresh = this.discovery.check(sysId, this.ship.x, this.ship.y, objects);
    for (const o of fresh) this.celebrateDiscovery(o);

    // Which discovered objects are NOT on screen right now? (The camera
    // never zooms, so the world view is scroll + canvas size.)
    const cam = this.cameras.main;
    const view = { left: cam.scrollX, top: cam.scrollY, w: this.scale.width, h: this.scale.height };
    const offscreen = [];
    for (const o of objects) {
      if (this.discovery.isDiscovered(sysId, o.id) && !circleInView(o.x, o.y, o.radius, view)) {
        offscreen.push(o);
      }
    }
    this.compass.refresh(offscreen, view, this.scale.width, this.scale.height, time, delta);
  }

  /** The discoverable objects of the system, with compass metadata. */
  discoverableObjects() {
    const out = [];
    out.push({
      id: 'home',
      x: this.planet.x,
      y: this.planet.y,
      radius: this.planet.radius,
      typeLabel: config.get('planets.homeTypeLabel', 'Home World'),
      name: config.get('planets.homeName', 'Terra'),
    });
    for (const p of this.systemPlanets) {
      out.push({
        id: p.discoveryId,
        x: p.x,
        y: p.y,
        radius: p.radius,
        typeLabel: config.get(`planets.typeLabels.${p.name}`, p.name),
        name: p.discoveryName,
      });
    }
    return out;
  }

  /** The "new object" moment: a rim ping at the world + a HUD toast. */
  celebrateDiscovery(o) {
    const neon = themeColor('neon', 0x00e5ff);

    // Expanding ring at the world's rim (world space).
    const ring = this.add.circle(o.x, o.y, o.radius, 0, 0).setStrokeStyle(2, neon, 0.9).setDepth(6);
    this.tweens.add({
      targets: ring,
      scale: 1.12,
      alpha: 0,
      duration: 750,
      ease: 'Sine.easeOut',
      onComplete: () => ring.destroy(),
    });

    // Top-center HUD toast, in the console language.
    if (Array.isArray(this.toast)) {
      for (const g of this.toast) g.destroy();
    }
    const fam = BODY_FONT();
    const type = (o.typeLabel ?? 'OBJECT').toUpperCase();
    const name = o.name ? String(o.name).toUpperCase() : null;
    const label = name ? `DISCOVERED  —  ${name}  ·  ${type}` : `DISCOVERED  —  ${type}`;
    const g1 = this.add
      .text(0, 0, '\u25b8', { fontFamily: fam, fontSize: '12px', color: toCss(neon) })
      .setOrigin(0, 0.5)
      .setScrollFactor(0); // UI — pinned to the screen, not the world
    const g2 = this.add
      .text(0, 0, label, {
        fontFamily: fam,
        fontSize: '11px',
        color: toCss(themeColor('dim', 0x7d92c4)),
        letterSpacing: 2,
      })
      .setOrigin(0, 0.5)
      .setScrollFactor(0); // UI — pinned to the screen, not the world
    const total = g1.width + 10 + g2.width;
    const x0 = this.scale.width / 2 - total / 2;
    g1.setPosition(x0, 26).setDepth(45).setAlpha(0);
    g2.setPosition(x0 + g1.width + 10, 26).setDepth(45).setAlpha(0);
    this.toast = [g1, g2];
    this.tweens.add({ targets: this.toast, alpha: 1, duration: 180, ease: 'Sine.easeOut' });
    this.time.delayedCall(2400, () => {
      if (!Array.isArray(this.toast)) return;
      const [a, b] = this.toast;
      this.toast = null;
      this.tweens.add({
        targets: [a, b],
        alpha: 0,
        duration: 350,
        onComplete: () => {
          a.destroy();
          b.destroy();
        },
      });
    });
  }

  showTargetMarker(x, y) {
    const color = toColor(config.get('game.markerColor', '#41c7ff'));
    const marker = this.add.circle(x, y, 10, color, 0.8).setDepth(5);
    this.tweens.add({
      targets: marker,
      scale: 2.4,
      alpha: 0,
      duration: 450,
      ease: 'Sine.easeOut',
      onComplete: () => marker.destroy(),
    });
  }

  hideHint() {
    if (!this.hint || !this.hint.active) return;
    this.tweens.add({
      targets: this.hint,
      alpha: 0,
      duration: 400,
      onComplete: () => {
        this.hint.destroy();
        this.hint = null;
      },
    });
  }

  shutdown() {
    this.starfield?.destroy();
    this.compass?.destroy();
    this.actionBar?.destroy();
  }
}