// 玩家：还原 IWBT 的硬核手感 —— 松手即停、无加速、可变跳跃高度、二段跳。
// 与 web 版 player.js 1:1 对应（逐帧积分完全一致，保证手感）。
import 'dart:ui' show Canvas;
import 'dart:math' show pi, max, min;
import 'package:iwbtc/src/core/util.dart';
import 'package:iwbtc/src/core/input.dart';
import 'package:iwbtc/src/audio/sfx.dart';
import 'package:iwbtc/src/game/sprites.dart';
import 'package:iwbtc/src/game/views.dart';
import 'package:iwbtc/src/game/level.dart' show Level, Tile, Mover, Cell, Bullet;

class SavePoint {
  double x, y;
  int face;
  SavePoint(this.x, this.y, this.face);
}

class PHY {
  // 2026-10-25：手感「稍微飘一点」。飘 = 更低重力换更长滞空，但高度由
  // v²/(2g) 决定——同比例降重力并提初速即可让顶点高度零变化：
  //   GRAV 0.25→0.23、GRAV_FALL 0.32→0.30、GRAV_DJ 0.35→0.322
  //   JUMP 6.6→6.326、DJUMP 6.7→6.420（按引擎积分顺序反解，单跳顶点仍
  //   83.85px、二段自身仍 60.80px，总高仍 4.5 格；滞空 49→51 帧 ≈ +4%）。
  // HSPD / MAXFALL / DJ_INERTIA / WATER_* / ICE_* / SLIDE_* 未动。
  static const double GRAV = 0.23;
  static const double GRAV_FALL = 0.30;
  static const double GRAV_DJ = 0.322;
  static const double MAXFALL = 9;
  static const double JUMP = 6.326;
  static const double DJUMP = 6.420;
  static const double DJ_INERTIA = 0;
  static const double HSPD = 2.6;
  static const double WATER_GRAV = 0.16;
  static const double WATER_FALL = 2.6;
  static const double WATER_RISE = 0.42;
  static const double ICE_ACC = 0.18;
  static const double ICE_FRIC = 0.07;
  static const double SLIDE_FRIC = 0.12;
  static const double SLIDE_AIR = 0.02;
  static const double SLIDE_EASE = 0.14;
  static const double SLIDE_BRAKE = 0.45;
  static const double SLIDE_MIN = 0.35;
  static const double SLIDE_STOP = 0.05;
  static const double ICE_TOP = 1.6;
}

class Player implements PlayerView {
  Level level;
  double w = 11, h = 21;
  double x = 0, y = 0;
  double vx = 0, vy = 0;
  int jumps = 0;
  bool djUp = false;
  bool grounded = false;
  int facing = 1;
  bool alive = true;
  bool dead = false;
  int deadT = 0;
  double deathX = 0, deathY = 0;
  bool inWater = false;
  int animT = 0;
  int shootCool = 0;
  Mover? mover;
  bool sliding = false;
  bool justRespawned = false;
  bool hasGun = false;
  int apples = 0;
  SavePoint? savePoint;
  int saveIdx = 0;
  bool clearing = false;

  // 回调（由 World 设置）
  void Function()? onDeath;
  void Function()? onClear;
  void Function(dynamic e)? onPortal;
  void Function()? onRespawnFace;

  Player(this.level) {
    reset(true);
  }

  double get cx => x + w / 2;
  double get cy => y + h / 2;

  void reset(bool full) {
    final sp = (full || savePoint == null)
        ? SavePoint(level.spawn.x, level.spawn.y, level.faceIndex ?? 0)
        : savePoint!;
    x = sp.x; y = sp.y;
    vx = 0; vy = 0;
    jumps = 0;
    djUp = false;
    grounded = false;
    facing = 1;
    alive = true;
    dead = false;
    deadT = 0;
    deathX = 0; deathY = 0;
    inWater = false;
    animT = 0;
    shootCool = 0;
    mover = null;
    sliding = false;
    justRespawned = false;
    if (full) {
      hasGun = level.data['startGun'] == true;
      apples = 0;
      savePoint = null;
      saveIdx = 0;
    }
  }

  /// 纯死亡演出（不进死亡状态）：粒子爆开 + 屏幕轻震 + 死亡点扩散冲击环。
  void deathBurst() {
    final L = level;
    final dx = clamp(cx, 10, max(10, L.pxW - 10));
    final dy = clamp(cy, 10, max(10, L.pxH - 10));
    Sfx.instance.death();
    L.particles.spawn(dx, dy, 16, colors: const ['#ff5c7a', '#ff8095', '#fff', '#ffc63a'], speed: 3.4, life: 34, size: 3, grav: 0.16);
    L.shake = max(L.shake, 6);
    L.addDeathFX(dx, dy);
    deathX = dx; deathY = dy;
  }

  void kill([Map opts = const {}]) {
    if (dead || !alive) return;
    dead = true; alive = false; deadT = 0;
    vx = 0; vy = 0; sliding = false;
    deathBurst();
    if (opts['mark'] != false) level.addDeathMark(deathX, deathY);
    if (opts['count'] != false && onDeath != null) onDeath!();
  }

  void respawn() {
    dead = false; alive = true;
    final L = level;
    final sp = savePoint ?? SavePoint(L.spawn.x, L.spawn.y, 0);
    x = sp.x; y = sp.y;
    vx = 0; vy = 0; jumps = 0;
    djUp = false;
    shootCool = 0; sliding = false;
    deadT = 0;
    int guard = 0;
    while (L.solidRect(x, y, w, h) && guard++ < 48) y -= 2;
    L.softReset();
    justRespawned = true;
  }

  void update(int dt) {
    final L = level;
    animT++;
    if (shootCool > 0) shootCool--;

    if (dead) { deadT++; return; }

    final inWater = L.waterRect(x + 2, y + 4, w - 4, h - 4);
    if (inWater && !this.inWater) Sfx.instance.splash();
    this.inWater = inWater;

    final moveL = Input.held('left'), moveR = Input.held('right');
    final onIce = grounded && L.iceAtBottom(x, y, w, h);
    double target = 0;
    if (moveL && !moveR) target = -PHY.HSPD;
    else if (moveR && !moveL) target = PHY.HSPD;

    final ICE_MAX = PHY.HSPD * PHY.ICE_TOP;
    final decel = (double f) {
      if (vx.abs() <= f) vx = 0;
      else vx -= sgn(vx) * f;
    };

    if (onIce) {
      if (target != 0) vx += sgn(target) * PHY.ICE_ACC;
      else decel(PHY.ICE_FRIC);
      vx = clamp(vx, -ICE_MAX, ICE_MAX);
      if (vx.abs() > PHY.SLIDE_MIN) sliding = true;
    } else if (sliding && vx.abs() > PHY.SLIDE_STOP) {
      if (target != 0) {
        final dir = sgn(vx);
        if (dir == 0 || sgn(target) == dir) {
          if (vx.abs() >= PHY.HSPD) {
            vx -= dir * PHY.SLIDE_EASE;
            if (vx.abs() < PHY.HSPD) { vx = target; sliding = false; }
          } else {
            vx = target; sliding = false;
          }
        } else {
          vx -= dir * PHY.SLIDE_BRAKE;
          if (sgn(vx) == sgn(target)) { vx = target; sliding = false; }
        }
        vx = clamp(vx, -ICE_MAX, ICE_MAX);
      } else {
        decel(grounded ? PHY.SLIDE_FRIC : PHY.SLIDE_AIR);
        if (vx == 0) sliding = false;
      }
      if (vx != 0 && vx.abs() < PHY.SLIDE_STOP) { vx = 0; sliding = false; }
    } else {
      vx = target;
      sliding = false;
    }
    if (target != 0) facing = sgn(target).toInt();

    if (inWater) {
      if (Input.held('jump')) vy -= PHY.WATER_RISE;
      if (Input.held('down')) vy += 0.25;
      vy = clamp(vy, -3.2, PHY.WATER_FALL);
      jumps = 0; djUp = false;
    } else {
      if (Input.hit('jump')) {
        if (grounded || jumps == 0) {
          vy = -PHY.JUMP; jumps = 1; grounded = false;
          Sfx.instance.jump();
          L.particles.spawn(cx, y + h, 5, colors: const ['#fff', '#cfcfe0'], speed: 1.6, life: 16, size: 2, dir: -pi / 2, spread: 2);
        } else if (jumps == 1) {
          vy = max(vy, 0) * PHY.DJ_INERTIA - PHY.DJUMP; jumps = 2;
          djUp = vy < 0;
          Sfx.instance.djump();
          L.particles.spawn(cx, cy, 10, colors: const ['#fff', '#9ad8ff'], speed: 2.2, life: 20, size: 2, spread: pi * 2);
        }
      }
      if (!Input.held('jump') && vy < -3) vy = -3;
      vy = min(vy + (vy < 0 ? (djUp ? PHY.GRAV_DJ : PHY.GRAV) : PHY.GRAV_FALL), PHY.MAXFALL);
      if (djUp && vy >= 0) djUp = false;
    }

    if (mover != null && !(mover!.gone)) {
      x += mover!.dx;
      y += mover!.dy;
    }

    // X 轴移动
    final prevBottom = y + h;
    mover = null;
    double steps = vx.abs();
    final dx = sgn(vx).toDouble();
    while (steps > 0) {
      final m = min(1, steps);
      if (!L.solidRect(x + dx * m, y, w, h)) { x += dx * m; steps -= m; }
      else break;
    }
    if (L.solidRect(x + dx, y, w, h) && vx.abs() > 0) vx = 0;

    // Y 轴移动
    final dropThrough = Input.held('down');
    steps = vy.abs();
    final dy = sgn(vy).toDouble();
    bool hitGround = false;
    while (steps > 0) {
      final m = min(1, steps);
      final ny = y + dy * m;
      final solidHere = L.solidRect(x, ny, w, h, prevBottom: prevBottom, dropThrough: dropThrough);
      if (!solidHere) { y = ny; steps -= m; }
      else {
        if (dy > 0) hitGround = true;
        vy = 0;
        break;
      }
    }
    for (final m in L.movers) {
      if (m.gone) continue;
      if (x + w > m.x && x < m.x + m.w) {
        if (y + h >= m.y - 2 && y + h <= m.y + m.h) {
          mover = m; hitGround = true;
        }
      }
    }

    final wasAir = !grounded;
    grounded = hitGround || (vy == 0 && L.solidRect(x, y + 1, w, h));
    if (grounded) {
      jumps = 0; djUp = false;
    }

    if (sliding && grounded && vx.abs() > PHY.HSPD && animT % 5 == 0) {
      L.particles.spawn(cx - sgn(vx) * 5, y + h - 2, 2, colors: const ['#dff4ff', '#8fd8f0', '#fff'], speed: 1.1, life: 16, size: 2, dir: -pi / 2, spread: 1.7, grav: 0.1);
    }

    x = clamp(x, 0, L.pxW - w);
    if (y > L.pxH + 200) { kill(); return; }
    if (y < -300) { y = -300; vy = 0; }

    if (L.deadlyRect(x, y, w, h)) { kill(); return; }

    if (hasGun && Input.hit('shoot') && shootCool == 0 && L.bullets.length < 5) {
      shoot();
    }

    touchEntities();

    if (grounded) {
      final ty = ((y + h + 2) / TILE).floor();
      for (int tx = (x / TILE).floor(); tx <= ((x + w - 1) / TILE).floor(); tx++) {
        if (ty < L.tiles.length && tx >= 0 && tx < L.tiles[0].length && L.tiles[ty][tx] == Tile.vanish && L.vanishState(tx, ty) == 0) {
          L.setVanish(tx, ty, 1);
          L.vanishT ??= {};
          L.vanishT![ty * 1000 + tx] = 0;
        }
      }
    }
  }

  void shoot() {
    final L = level;
    shootCool = 9;
    L.bullets.add(Bullet(
      x: facing > 0 ? x + w - 2 : x - 6,
      y: y + 8, w: 10.0, h: 5.0,
      vx: 9.0 * facing, vy: 0.0, life: 130,
    ));
    Sfx.instance.shoot();
    L.particles.spawn(facing > 0 ? x + w : x, y + 10, 3, colors: const ['#fff6a0'], speed: 1.5, life: 10, size: 2);
  }

  void touchEntities() {
    final L = level;
    for (final e in L.entities) {
      if (e.dead) continue;
      final hit = e.type == 'save'
          ? overlap(Box(x - 6, y - 6, w + 12, h + 12), Box(e.x, e.y, e.w, e.h))
          : overlap(Box(x, y, w, h), Box(e.x, e.y, e.w, e.h));
      if (!hit) continue;
      switch (e.type) {
        case 'save':
          if (!e.active) {
            e.active = true;
            savePoint = SavePoint(e.x + e.w / 2 - w / 2, e.y + e.h - h, level.faceIndex ?? 0);
            saveIdx = e.no ?? 1;
            Sfx.instance.save();
            L.particles.spawn(e.x + e.w / 2, e.y + e.h / 2, 18, colors: const ['#b06bff', '#fff', '#e5d0ff'], speed: 2.6, life: 30);
            if (e.fake) { L.showToast('假的。', 90); kill(); return; }
          }
          break;
        case 'goal':
          if (!clearing) { clearing = true; if (onClear != null) onClear!(); }
          break;
        case 'gun':
          if (!e.taken) {
            e.taken = true; hasGun = true;
            L.particles.spawn(e.x + e.w / 2, e.y + e.h / 2, 12, colors: const ['#dfe0f0', '#fff'], speed: 2.2, life: 24);
            L.showToast('获得手枪！按 X 射击', 120);
            Sfx.instance.save();
          }
          break;
        case 'apple':
          if (!e.taken) { e.taken = true; apples++; Sfx.instance.save(); }
          break;
        case 'jumpref':
          if (animT % 4 == 0) jumps = 0;
          break;
        case 'warp':
          if (e.cool > 0) break;
          e.cool = 40;
          final to = e.to;
          if (to != null && to is Map && !to.containsKey('x') && !to.containsKey('y') && to['face'] is int) {
            if (onPortal != null) onPortal!(e);
            break;
          }
          double? nx, ny;
          if (to == 'spawn') {
            nx = L.spawn.x; ny = L.spawn.y;
          } else if (to != null && to is Map && to.containsKey('x')) {
            nx = (to['x'] as num) * TILE; ny = (to['y'] as num) * TILE;
          } else {
            final p = L.entities.firstWhere((o) => o.type == 'warp' && o.idx == e.pair, orElse: () => e);
            if (p != e) {
              nx = p.x + p.w / 2 - w / 2; ny = p.y + p.h - h;
            }
          }
          if (nx != null && ny != null) {
            x = nx; y = ny;
            vx = 0; vy = 0;
            final partner = L.entities.firstWhere((o) => o.type == 'warp' && o.idx == e.pair, orElse: () => e);
            if (partner != e) partner.cool = 40;
            Sfx.instance.warp();
            L.particles.spawn(cx, cy, 12, colors: const ['#a86bff', '#fff'], speed: 2.5, life: 24);
          }
          break;
        case 'sign':
          if (animT % 30 == 0) L.showToast(e.text ?? '', 90);
          break;
      }
    }
  }

  void draw(Canvas c) {
    if (dead) return;
    drawKid(c, this, animT);
  }
}