import React from 'react';
import type { Object3D } from 'three';
import {
  fourStrokePhaseLabel,
  crankSliderState,
  valveLift,
  windowPulse01,
} from '../../../animations/mechanics';
import type { MachineAnimationModule } from '../../../animations/types';
import {
  FlowArrow,
  MachinePart,
  Shaft,
  SpokedWheel,
} from './primitives';
import {
  EngineeringBaseplate,
  PartLabels,
  getPartVisualProps,
} from './proceduralSceneHelpers';
import type {
  ProceduralMachineDefinition,
  ProceduralMachineModule,
  ProceduralMachineSceneProps,
} from './types';

const definition: ProceduralMachineDefinition = {
  id: 'four-stroke-petrol-engine',
  slug: 'four-stroke-petrol-engine',
  title: 'Four Stroke Petrol Engine',
  subtitle: 'Spark-ignition piston engine with valve timing',
  category: 'Engines',
  difficulty: 'Intermediate',
  summary: 'A transparent single-cylinder petrol engine demonstrating intake, compression, power, and exhaust strokes.',
  description:
    'This procedural cutaway shows the kinematic relationship between crankshaft, connecting rod, piston, camshaft, poppet valves, spark plug, and gas exchange paths in a four-stroke spark-ignition engine. The crankshaft completes two revolutions per thermodynamic cycle while the camshaft rotates once, opening each valve at the correct stroke.',
  keywords: ['engine', 'piston', 'crankshaft', 'valves', 'spark ignition', 'otto cycle'],
  complexity: 6,
  dateAdded: '2025-02-04',
  typicalRpm: '800–6,500 RPM',
  facts: [
    {
      label: 'Cycle',
      value: '720° crank rotation',
      detail: 'A complete intake-compression-power-exhaust sequence takes two crank revolutions.',
    },
    {
      label: 'Valve train',
      value: 'Camshaft at 1/2 crank speed',
      detail: 'Four-stroke camshafts rotate once for every two crankshaft turns.',
    },
    {
      label: 'Common efficiency',
      value: '25–35%',
      detail: 'Real brake thermal efficiency depends on compression ratio, load, and friction.',
    },
    {
      label: 'Invented',
      value: '1876',
      detail: 'Nikolaus Otto commercialized the practical four-stroke cycle.',
    },
  ],
  parts: [
    {
      id: 'engine-block',
      name: 'Cylinder block',
      description:
        'Rigid structure that supports the cylinder bore, crank bearings, coolant jacket, and head mounting surfaces.',
      material: 'Cast aluminium / iron',
      engineeringNote: 'The block must handle combustion pressure while keeping crank and bore alignment stable.',
      labelPosition: [-1.08, 0.2, 0.85],
      defaultOpacity: 0.54,
    },
    {
      id: 'piston',
      name: 'Piston',
      description:
        'Reciprocating component that seals combustion pressure and transmits gas force through the wrist pin to the connecting rod.',
      material: 'Forged aluminium alloy',
      engineeringNote: 'Skirts guide side thrust while rings maintain compression and oil control.',
      labelPosition: [0.72, 0.45, 0.9],
    },
    {
      id: 'connecting-rod',
      name: 'Connecting rod',
      description:
        'Pinned link between piston and crank throw that converts reciprocating piston motion into crank rotation.',
      material: 'Forged steel',
      engineeringNote: 'The rod angle creates side thrust on the piston and alternating tensile/compressive loads.',
      labelPosition: [0.98, -0.65, 0.78],
    },
    {
      id: 'crankshaft',
      name: 'Crankshaft',
      description: 'Rotating shaft with an offset crank throw that converts linear piston force into torque.',
      material: 'Nitrided steel',
      engineeringNote: 'Counterweights reduce shaking forces and bearing loads.',
      labelPosition: [-0.9, -1.12, 0.75],
    },
    {
      id: 'crank-throw',
      name: 'Crank throw',
      description: 'Offset journal defining stroke length and moving the big end of the connecting rod.',
      material: 'Hardened steel journal',
      labelPosition: [0.62, -1.18, 0.7],
    },
    {
      id: 'camshaft',
      name: 'Camshaft',
      description: 'Lobed shaft that opens valves with a two-to-one timing ratio relative to the crankshaft.',
      material: 'Chilled cast iron / steel',
      engineeringNote: 'Cam phase determines breathing, overlap, idle quality, and power curve.',
      labelPosition: [-0.92, 1.35, 0.76],
    },
    {
      id: 'intake-valve',
      name: 'Intake valve',
      description: 'Poppet valve admitting fresh air-fuel mixture during the intake stroke.',
      material: 'Chromium alloy steel',
      labelPosition: [-0.5, 1.12, 0.85],
    },
    {
      id: 'exhaust-valve',
      name: 'Exhaust valve',
      description: 'Heat-resistant poppet valve allowing combustion products to leave during the exhaust stroke.',
      material: 'Austenitic stainless steel',
      labelPosition: [0.5, 1.12, 0.85],
    },
    {
      id: 'spark-plug',
      name: 'Spark plug',
      description: 'Insulated electrode that ignites the compressed mixture near top dead centre.',
      material: 'Ceramic insulator and nickel electrodes',
      engineeringNote: 'Ignition timing is advanced before TDC at higher RPM so pressure peaks after TDC.',
      labelPosition: [0, 1.65, 0.82],
    },
    {
      id: 'intake-flow',
      name: 'Intake charge',
      description: 'Blue flow markers visualize fresh mixture entering the cylinder while the intake valve is open.',
      labelPosition: [-1.45, 1.08, 0.65],
    },
    {
      id: 'exhaust-flow',
      name: 'Exhaust gases',
      description: 'Warm flow markers visualize hot exhaust leaving through the exhaust valve.',
      labelPosition: [1.45, 1.08, 0.65],
    },
    {
      id: 'flywheel',
      name: 'Flywheel',
      description: 'Rotational inertia that smooths torque delivery between combustion events.',
      material: 'Cast steel',
      labelPosition: [1.35, -1.18, 0.62],
    },
  ],
  cameraPresets: [
    { id: 'iso', label: 'Isometric', position: [3.4, 2.5, 4.2], target: [0, 0, 0], fov: 42 },
    { id: 'front', label: 'Front cutaway', position: [0, 0.4, 5.2], target: [0, 0, 0], fov: 38 },
    { id: 'side', label: 'Valve timing', position: [4.8, 0.4, 1.2], target: [0, 0, 0.1], fov: 42 },
  ],
  tour: {
    id: 'tour-four-stroke-petrol-engine',
    machineId: 'four-stroke-petrol-engine',
    title: 'Follow one complete four-stroke cycle',
    description:
      'A guided walkthrough of the piston motion, valve timing, ignition event, and crankshaft energy smoothing.',
    steps: [
      {
        id: 'intake',
        title: '1. Intake stroke',
        body: 'The piston descends, the intake valve opens, and fresh mixture is drawn through the port.',
        durationSeconds: 5,
        partIds: ['piston', 'intake-valve', 'intake-flow'],
        phaseRange: [0.02, 0.22],
        rpm: 900,
        camera: { position: [2.7, 1.6, 4.3], target: [0, 0.25, 0], duration: 1.2 },
      },
      {
        id: 'compression',
        title: '2. Compression stroke',
        body: 'Both valves close as the piston rises and compresses the charge before ignition.',
        durationSeconds: 4.5,
        partIds: ['piston', 'engine-block', 'spark-plug'],
        phaseRange: [0.27, 0.46],
        rpm: 900,
        camera: { position: [0.8, 1.1, 4.6], target: [0, 0.55, 0], duration: 1.1 },
      },
      {
        id: 'power',
        title: '3. Combustion / power stroke',
        body: 'The spark plug fires near top dead centre and gas pressure accelerates the piston downward.',
        durationSeconds: 5,
        partIds: ['spark-plug', 'piston', 'connecting-rod', 'crankshaft'],
        phaseRange: [0.5, 0.7],
        rpm: 780,
        camera: { position: [3.3, 1.5, 3.4], target: [0, -0.2, 0], duration: 1.15 },
      },
      {
        id: 'exhaust',
        title: '4. Exhaust stroke',
        body: 'The exhaust valve opens while the piston rises to clear spent gases from the cylinder.',
        durationSeconds: 4.5,
        partIds: ['exhaust-valve', 'exhaust-flow', 'piston'],
        phaseRange: [0.76, 0.96],
        rpm: 900,
        camera: { position: [-2.8, 1.6, 4.2], target: [0.15, 0.35, 0], duration: 1.2 },
      },
    ],
  },
  relatedMachineIds: ['wankel-rotary-engine', 'disc-brake-caliper', 'centrifugal-pump'],
};

function partProps(
  partId: string,
  props: ProceduralMachineSceneProps,
  explodeDirection: [number, number, number] = [0, 0, 0],
) {
  return {
    partId,
    registerPart: props.registerPart,
    explodeDirection,
    explodedDistance: props.explodedDistance ?? 0,
    onSelectPart: props.onSelectPart,
    onHoverPart: props.onHoverPart,
    ...getPartVisualProps(partId, props),
  };
}

function setPosition(object: Object3D | undefined, x: number, y: number, z: number): void {
  if (object) object.position.set(x, y, z);
}

export const fourStrokePetrolEngineAnimation: MachineAnimationModule = {
  id: 'four-stroke-petrol-engine-cycle',
  machineId: 'four-stroke-petrol-engine',
  label: 'Four-stroke crank-valve animation',
  version: '1.0.0',
  defaultRpm: 900,
  minRpm: 120,
  maxRpm: 6500,
  cycleRevolutions: 2,
  cycleSteps: 16,
  loop: true,
  supportsReverse: true,
  reducedMotionStrategy: 'slow',
  update(context) {
    const crankRadius = 0.42;
    const rodLength = 1.24;
    const crankCenterY = -1.02;
    const pistonOffsetY = -0.12;
    const crank = crankSliderState(context.shaftAngle, crankRadius, rodLength);
    const pistonY = pistonOffsetY + (crank.pistonY - rodLength);
    const crankPinX = crank.crankPinX;
    const crankPinY = crankCenterY + crank.crankPinY;
    const pistonPinY = pistonY - 0.3;
    const rodMidY = (crankPinY + pistonPinY) / 2;
    const rodMidX = crankPinX / 2;
    const rodLengthNow = Math.hypot(crankPinX, pistonPinY - crankPinY);
    const cycleProgress = context.cycleProgress;
    const intakeLift = valveLift(cycleProgress, 0.1, 0.28, 0.22);
    const exhaustLift = valveLift(cycleProgress, 0.88, 0.28, 0.22);
    const sparkPulse = windowPulse01(cycleProgress, 0.485, 0.525);
    const intakeFlow = windowPulse01(cycleProgress, 0.02, 0.23);
    const exhaustFlow = windowPulse01(cycleProgress, 0.78, 0.98);

    setPosition(context.getPart('piston'), 0, pistonY, 0);
    setPosition(context.getPart('crank-throw'), crankPinX, crankPinY, 0);
    setPosition(context.getPart('connecting-rod'), rodMidX, rodMidY, 0);

    const rod = context.getPart('connecting-rod');
    if (rod) {
      rod.rotation.z = -Math.atan2(crankPinX, pistonPinY - crankPinY);
      rod.scale.set(1, rodLengthNow, 1);
    }

    const crankshaft = context.getPart('crankshaft');
    if (crankshaft) crankshaft.rotation.z = -context.shaftAngle;

    const flywheel = context.getPart('flywheel');
    if (flywheel) flywheel.rotation.z = -context.shaftAngle;

    const camshaft = context.getPart('camshaft');
    if (camshaft) camshaft.rotation.z = -context.shaftAngle / 2;

    const intakeValve = context.getPart('intake-valve');
    if (intakeValve) intakeValve.position.y = 1.08 - intakeLift;

    const exhaustValve = context.getPart('exhaust-valve');
    if (exhaustValve) exhaustValve.position.y = 1.08 - exhaustLift;

    const spark = context.getPart('spark-plug');
    if (spark) spark.scale.setScalar(1 + sparkPulse * 0.18);

    const intake = context.getPart('intake-flow');
    if (intake) {
      intake.visible = intakeFlow > 0.04;
      intake.position.x = -1.08 + intakeFlow * 0.16;
      intake.scale.setScalar(0.8 + intakeFlow * 0.45);
    }

    const exhaust = context.getPart('exhaust-flow');
    if (exhaust) {
      exhaust.visible = exhaustFlow > 0.04;
      exhaust.position.x = 1.08 + exhaustFlow * 0.24;
      exhaust.scale.setScalar(0.8 + exhaustFlow * 0.55);
    }

    context.setPartOpacity('intake-flow', intakeFlow);
    context.setPartOpacity('exhaust-flow', exhaustFlow);
    context.clearHighlights();
    const phaseLabel = fourStrokePhaseLabel(cycleProgress);
    context.setPhaseLabel(phaseLabel);

    if (cycleProgress < 0.25) context.highlightParts(['intake-valve', 'intake-flow'], 0.8);
    else if (cycleProgress < 0.5) context.highlightPart('piston', 0.6);
    else if (cycleProgress < 0.75) context.highlightParts(['spark-plug', 'connecting-rod', 'crankshaft'], 0.85);
    else context.highlightParts(['exhaust-valve', 'exhaust-flow'], 0.8);
  },
};

export function FourStrokePetrolEngineScene(props: ProceduralMachineSceneProps): JSX.Element {
  return (
    <group>
      <EngineeringBaseplate width={4.6} depth={3.1} />

      <MachinePart {...partProps('engine-block', props, [-0.55, 0.05, -0.1])} opacity={props.partState?.['engine-block']?.opacity ?? 0.48}>
        <mesh position={[0, 0.16, 0]} castShadow receiveShadow>
          <boxGeometry args={[1.32, 2.42, 0.92]} />
          <meshStandardMaterial color="#324052" metalness={0.42} roughness={0.45} transparent opacity={0.48} />
        </mesh>
        <mesh position={[0, 0.3, 0.48]}>
          <boxGeometry args={[0.72, 1.72, 0.04]} />
          <meshBasicMaterial color="#4c8dff" transparent opacity={0.18} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('piston', props, [0.6, 0.1, 0.2])}>
        <mesh castShadow receiveShadow>
          <cylinderGeometry args={[0.35, 0.35, 0.42, 42]} />
          <meshStandardMaterial color="#d4d9e2" metalness={0.78} roughness={0.28} />
        </mesh>
        <mesh position={[0, -0.24, 0]}>
          <torusGeometry args={[0.29, 0.018, 10, 48]} />
          <meshStandardMaterial color="#222a36" metalness={0.7} roughness={0.35} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('connecting-rod', props, [0.45, -0.15, 0.15])}>
        <mesh castShadow receiveShadow>
          <boxGeometry args={[0.14, 1, 0.12]} />
          <meshStandardMaterial color="#a9b4c3" metalness={0.86} roughness={0.24} />
        </mesh>
        <mesh position={[0, 0.5, 0]}>
          <sphereGeometry args={[0.13, 24, 16]} />
          <meshStandardMaterial color="#c5ceda" metalness={0.82} roughness={0.25} />
        </mesh>
        <mesh position={[0, -0.5, 0]}>
          <sphereGeometry args={[0.16, 24, 16]} />
          <meshStandardMaterial color="#c5ceda" metalness={0.82} roughness={0.25} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('crankshaft', props, [-0.5, -0.28, 0])} position={[0, -1.02, 0]}>
        <Shaft length={1.8} radius={0.09} axis="x" color="#99a5b7" />
        <SpokedWheel radius={0.5} tube={0.045} spokes={4} />
      </MachinePart>

      <MachinePart {...partProps('crank-throw', props, [0.38, -0.32, 0.15])}>
        <mesh castShadow receiveShadow>
          <sphereGeometry args={[0.13, 28, 18]} />
          <meshStandardMaterial color="#ffb04c" metalness={0.72} roughness={0.28} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('flywheel', props, [0.72, -0.2, 0.2])} position={[1.05, -1.02, 0]}>
        <SpokedWheel radius={0.46} tube={0.06} spokes={8} color="#556172" />
      </MachinePart>

      <MachinePart {...partProps('camshaft', props, [-0.38, 0.28, 0.15])} position={[0, 1.36, 0]}>
        <Shaft length={1.55} radius={0.055} axis="x" color="#8390a3" />
        <mesh position={[-0.32, 0, 0]} rotation={[0, 0, 0.6]} castShadow>
          <boxGeometry args={[0.18, 0.42, 0.1]} />
          <meshStandardMaterial color="#9ca8b9" metalness={0.78} roughness={0.3} />
        </mesh>
        <mesh position={[0.32, 0, 0]} rotation={[0, 0, -0.6]} castShadow>
          <boxGeometry args={[0.18, 0.42, 0.1]} />
          <meshStandardMaterial color="#9ca8b9" metalness={0.78} roughness={0.3} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('intake-valve', props, [-0.4, 0.28, 0.1])} position={[-0.32, 1.08, 0]}>
        <Shaft length={0.56} radius={0.028} axis="y" color="#90a1b7" />
        <mesh position={[0, -0.33, 0]} castShadow>
          <cylinderGeometry args={[0.13, 0.09, 0.055, 24]} />
          <meshStandardMaterial color="#7da8ff" metalness={0.75} roughness={0.28} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('exhaust-valve', props, [0.4, 0.28, 0.1])} position={[0.32, 1.08, 0]}>
        <Shaft length={0.56} radius={0.028} axis="y" color="#90a1b7" />
        <mesh position={[0, -0.33, 0]} castShadow>
          <cylinderGeometry args={[0.13, 0.09, 0.055, 24]} />
          <meshStandardMaterial color="#ff9d5c" metalness={0.75} roughness={0.28} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('spark-plug', props, [0, 0.42, 0.16])} position={[0, 1.55, 0]}>
        <mesh castShadow>
          <cylinderGeometry args={[0.055, 0.055, 0.42, 20]} />
          <meshStandardMaterial color="#f1f5ff" metalness={0.2} roughness={0.3} />
        </mesh>
        <mesh position={[0, -0.26, 0]}>
          <sphereGeometry args={[0.07, 24, 16]} />
          <meshStandardMaterial color="#ffb04c" emissive="#ff7d2c" emissiveIntensity={0.8} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('intake-flow', props, [-0.55, 0.16, 0.16])} position={[-1.16, 0.95, 0.1]}>
        <FlowArrow color="#4c8dff" />
        <FlowArrow color="#4c8dff" length={0.46} />
      </MachinePart>

      <MachinePart {...partProps('exhaust-flow', props, [0.55, 0.16, 0.16])} position={[1.14, 0.95, 0.1]} rotation={[0, 0, Math.PI]}>
        <FlowArrow color="#ffb04c" />
        <FlowArrow color="#ff8a4c" length={0.48} />
      </MachinePart>

      <PartLabels parts={definition.parts} visible={props.labelsVisible} />
    </group>
  );
}

export const fourStrokePetrolEngine: ProceduralMachineModule = {
  definition,
  animationModule: fourStrokePetrolEngineAnimation,
  Scene: FourStrokePetrolEngineScene,
};