import React, { useMemo } from 'react';
import {
  ExtrudeGeometry,
  Shape,
  Vector2,
} from 'three';
import { wankelState } from '../../../animations/mechanics';
import type { MachineAnimationModule } from '../../../animations/types';
import {
  FlowArrow,
  MachinePart,
  Shaft,
} from './primitives';
import {
  EngineeringBaseplate,
  PartLabels,
  getPartVisualProps,
} from './proceduralSceneHelpers';
import type {
  ProceduralMachineDefinition,
  ProceduralMachineModule,
  ProceduralMachineSceneProps,
} from './types';

const APEX_RADIUS = 0.95;

const definition: ProceduralMachineDefinition = {
  id: 'wankel-rotary-engine',
  slug: 'wankel-rotary-engine',
  title: 'Wankel Rotary Engine',
  subtitle: 'Eccentric triangular rotor in epitrochoid housing',
  category: 'Engines',
  difficulty: 'Advanced',
  summary: 'A rotary engine cutaway showing eccentric shaft motion, three apex seals, port timing, and combustion chamber pulse.',
  description:
    'The Wankel engine replaces reciprocating pistons with a rounded triangular rotor orbiting inside an epitrochoid housing. The rotor turns at one third of eccentric shaft speed while its chambers pass intake, compression, combustion, and exhaust regions.',
  keywords: ['wankel', 'rotary engine', 'epitrochoid', 'apex seal', 'eccentric shaft'],
  complexity: 8,
  dateAdded: '2025-02-04',
  typicalRpm: '1,000–9,000 RPM',
  facts: [
    {
      label: 'Rotor speed',
      value: '1/3 eccentric shaft speed',
      detail: 'The output shaft turns three times for one rotor revolution.',
    },
    {
      label: 'Chambers',
      value: 'Three working chambers',
      detail: 'Each rotor face forms a moving chamber with the epitrochoid housing.',
    },
    {
      label: 'Strength',
      value: 'High power density',
      detail: 'Smooth rotary motion and compact packaging are major advantages.',
    },
    {
      label: 'Challenge',
      value: 'Apex sealing',
      detail: 'Apex seals must maintain compression across high sliding speed and temperature.',
    },
  ],
  parts: [
    {
      id: 'housing',
      name: 'Epitrochoid housing',
      description: 'Two-lobed chamber profile that guides the rotor apex seals.',
      material: 'Aluminium housing with hard-coated running surface',
      labelPosition: [-1.55, 1.12, 0.78],
      defaultOpacity: 0.46,
    },
    {
      id: 'rotor',
      name: 'Triangular rotor',
      description: 'Rounded triangular rotor creating three moving combustion chambers.',
      material: 'Cast iron / steel rotor',
      labelPosition: [0.72, 0.18, 0.86],
    },
    {
      id: 'eccentric-shaft',
      name: 'Eccentric shaft',
      description: 'Output shaft with offset journal driving the rotor orbit.',
      material: 'Forged steel',
      labelPosition: [1.45, -0.78, 0.7],
    },
    {
      id: 'apex-seal-a',
      name: 'Apex seal A',
      description: 'Spring-loaded seal maintaining contact at one rotor tip.',
      labelPosition: [1.35, 0.75, 0.9],
    },
    {
      id: 'apex-seal-b',
      name: 'Apex seal B',
      description: 'Second rotor-tip seal separating adjacent chambers.',
      labelPosition: [-1.2, 0.95, 0.9],
    },
    {
      id: 'apex-seal-c',
      name: 'Apex seal C',
      description: 'Third apex seal completing chamber sealing around the rotor.',
      labelPosition: [0, -1.4, 0.9],
    },
    {
      id: 'intake-port',
      name: 'Intake port',
      description: 'Port opened by rotor motion to admit fresh charge.',
      labelPosition: [-1.78, -0.48, 0.72],
    },
    {
      id: 'exhaust-port',
      name: 'Exhaust port',
      description: 'Port uncovered by rotor motion to release exhaust gas.',
      labelPosition: [1.78, 0.5, 0.72],
    },
    {
      id: 'spark-plug',
      name: 'Spark plug',
      description: 'Ignition source positioned near the compressed chamber.',
      labelPosition: [0.2, 1.55, 0.82],
    },
    {
      id: 'combustion-pocket',
      name: 'Combustion pulse',
      description: 'Warm glow representing the chamber firing event.',
      labelPosition: [0.78, 1.1, 0.92],
    },
    {
      id: 'intake-flow',
      name: 'Intake flow',
      description: 'Blue flow marker showing port induction.',
      labelPosition: [-2.05, -0.85, 0.65],
    },
    {
      id: 'exhaust-flow',
      name: 'Exhaust flow',
      description: 'Warm flow marker showing exhaust discharge.',
      labelPosition: [2.0, 0.85, 0.65],
    },
  ],
  cameraPresets: [
    { id: 'iso', label: 'Isometric', position: [3.5, 2.4, 4.1], target: [0, 0, 0], fov: 40 },
    { id: 'front', label: 'Housing profile', position: [0, 0.3, 5.1], target: [0, 0, 0], fov: 36 },
    { id: 'ports', label: 'Port timing', position: [3.7, 1.5, 3.3], target: [0.15, 0.15, 0], fov: 42 },
  ],
  tour: {
    id: 'tour-wankel-rotary-engine',
    machineId: 'wankel-rotary-engine',
    title: 'Inside a Wankel rotary cycle',
    description: 'Follow the rotor orbit, apex seals, port timing, and combustion pulse.',
    steps: [
      {
        id: 'eccentric',
        title: 'Eccentric shaft drives orbit',
        body: 'The eccentric journal makes the rotor center orbit while the rotor turns more slowly.',
        durationSeconds: 4.5,
        partIds: ['eccentric-shaft', 'rotor'],
        camera: { position: [2.8, 1.5, 4.0], target: [0, 0, 0], duration: 1.1 },
        rpm: 720,
      },
      {
        id: 'seals',
        title: 'Apex seals define chambers',
        body: 'Three apex seals sweep the housing and keep adjacent gas chambers separated.',
        durationSeconds: 5,
        partIds: ['apex-seal-a', 'apex-seal-b', 'apex-seal-c', 'housing'],
        camera: { position: [0.5, 1.5, 4.7], target: [0, 0.05, 0], duration: 1.1 },
        rpm: 620,
      },
      {
        id: 'ports',
        title: 'Ports open by geometry',
        body: 'The rotor itself uncovers intake and exhaust ports rather than using poppet valves.',
        durationSeconds: 5,
        partIds: ['intake-port', 'exhaust-port', 'intake-flow', 'exhaust-flow'],
        phaseRange: [0.05, 0.32],
        camera: { position: [3.3, 1.4, 3.5], target: [0.15, 0.05, 0], duration: 1.1 },
      },
      {
        id: 'combustion',
        title: 'Combustion expands one chamber',
        body: 'A spark ignites the compressed charge and pressure drives the rotor around the eccentric.',
        durationSeconds: 4.5,
        partIds: ['spark-plug', 'combustion-pocket', 'rotor'],
        phaseRange: [0.5, 0.66],
        camera: { position: [-2.8, 1.8, 3.7], target: [0, 0.3, 0], duration: 1.1 },
      },
    ],
  },
  relatedMachineIds: ['four-stroke-petrol-engine', 'centrifugal-pump', 'ball-bearing'],
};

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 useEpitrochoidGeometry(): ExtrudeGeometry {
  return useMemo(() => {
    const points: Vector2[] = [];
    const samples = 180;

    for (let index = 0; index < samples; index += 1) {
      const t = (index / samples) * Math.PI * 2;
      const r = 1.22 + 0.28 * Math.cos(2 * t);
      points.push(new Vector2(Math.cos(t) * r, Math.sin(t) * (1.0 + 0.22 * Math.cos(2 * t))));
    }

    const shape = new Shape(points);
    const geometry = new ExtrudeGeometry(shape, {
      depth: 0.22,
      bevelEnabled: true,
      bevelSegments: 3,
      bevelSize: 0.025,
      bevelThickness: 0.025,
    });
    geometry.center();
    return geometry;
  }, []);
}

function useRotorGeometry(): ExtrudeGeometry {
  return useMemo(() => {
    const points: Vector2[] = [];
    const samples = 150;

    for (let index = 0; index < samples; index += 1) {
      const t = (index / samples) * Math.PI * 2;
      const radius = 0.72 + 0.14 * Math.cos(3 * t);
      points.push(new Vector2(Math.cos(t) * radius, Math.sin(t) * radius));
    }

    const shape = new Shape(points);
    const geometry = new ExtrudeGeometry(shape, {
      depth: 0.24,
      bevelEnabled: true,
      bevelSegments: 4,
      bevelSize: 0.035,
      bevelThickness: 0.035,
    });
    geometry.center();
    return geometry;
  }, []);
}

export const wankelRotaryEngineAnimation: MachineAnimationModule = {
  id: 'wankel-eccentric-rotor-cycle',
  machineId: 'wankel-rotary-engine',
  label: 'Eccentric rotor, apex seals, and port timing',
  version: '1.0.0',
  defaultRpm: 720,
  minRpm: 80,
  maxRpm: 9000,
  cycleRevolutions: 3,
  cycleSteps: 18,
  loop: true,
  supportsReverse: true,
  reducedMotionStrategy: 'slow',
  update(context) {
    const state = wankelState(context.shaftAngle);
    const centerX = state.eccentricCenterX;
    const centerY = state.eccentricCenterY;

    const rotor = context.getPart('rotor');
    if (rotor) {
      rotor.position.set(centerX, centerY, 0.08);
      rotor.rotation.z = state.rotorAngle;
    }

    const shaft = context.getPart('eccentric-shaft');
    if (shaft) shaft.rotation.z = -state.shaftAngle;

    const apexIds = ['apex-seal-a', 'apex-seal-b', 'apex-seal-c'];
    apexIds.forEach((id, index) => {
      const apex = context.getPart(id);
      if (!apex) return;
      const localAngle = state.rotorAngle + (index / 3) * Math.PI * 2;
      apex.position.set(
        centerX + Math.cos(localAngle) * APEX_RADIUS,
        centerY + Math.sin(localAngle) * APEX_RADIUS,
        0.22,
      );
      apex.rotation.z = localAngle + Math.PI / 2;
    });

    const combustion = context.getPart('combustion-pocket');
    if (combustion) {
      combustion.visible = state.combustionPulse > 0.03;
      combustion.position.set(centerX + 0.46, centerY + 0.62, 0.18);
      combustion.scale.setScalar(0.42 + state.combustionPulse * 0.62);
    }
    context.setPartOpacity('combustion-pocket', state.combustionPulse);

    const intake = context.getPart('intake-flow');
    const intakePulse = Math.max(0, Math.sin(state.chamberPhase * Math.PI * 2 + 0.9));
    if (intake) {
      intake.visible = intakePulse > 0.05;
      intake.position.x = -1.55 + intakePulse * 0.18;
      intake.scale.setScalar(0.84 + intakePulse * 0.32);
    }
    context.setPartOpacity('intake-flow', intakePulse);

    const exhaust = context.getPart('exhaust-flow');
    const exhaustPulse = Math.max(0, Math.sin(state.chamberPhase * Math.PI * 2 - 1.7));
    if (exhaust) {
      exhaust.visible = exhaustPulse > 0.05;
      exhaust.position.x = 1.55 + exhaustPulse * 0.22;
      exhaust.scale.setScalar(0.84 + exhaustPulse * 0.38);
    }
    context.setPartOpacity('exhaust-flow', exhaustPulse);

    context.setPhaseLabel(
      state.combustionPulse > 0.3
        ? 'Combustion chamber expanding — rotor drives eccentric shaft'
        : 'Rotor orbiting — ports open and close by housing geometry',
    );

    context.clearHighlights();
    if (state.combustionPulse > 0.3) context.highlightParts(['spark-plug', 'combustion-pocket', 'rotor'], 0.9);
    else if (intakePulse > exhaustPulse) context.highlightParts(['intake-port', 'intake-flow'], 0.72);
    else context.highlightParts(['apex-seal-a', 'apex-seal-b', 'apex-seal-c'], 0.7);
  },
};

export function WankelRotaryEngineScene(props: ProceduralMachineSceneProps): JSX.Element {
  const housingGeometry = useEpitrochoidGeometry();
  const rotorGeometry = useRotorGeometry();

  return (
    <group>
      <EngineeringBaseplate width={4.8} depth={3.2} />

      <MachinePart {...partProps('housing', props, [-0.22, 0.16, -0.08])} opacity={props.partState?.housing?.opacity ?? 0.44}>
        <mesh geometry={housingGeometry} castShadow receiveShadow>
          <meshStandardMaterial color="#2f3d52" transparent opacity={0.46} metalness={0.48} roughness={0.43} />
        </mesh>
        <mesh position={[0, 0, 0.14]}>
          <torusGeometry args={[1.38, 0.025, 8, 128]} />
          <meshBasicMaterial color="#4c8dff" transparent opacity={0.18} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('rotor', props, [0.22, 0.06, 0.2])} position={[0.34, 0, 0.08]}>
        <mesh geometry={rotorGeometry} castShadow receiveShadow>
          <meshStandardMaterial color="#9fa8b7" metalness={0.82} roughness={0.27} />
        </mesh>
        <mesh position={[0, 0, 0.17]}>
          <cylinderGeometry args={[0.2, 0.2, 0.12, 36]} />
          <meshStandardMaterial color="#283244" metalness={0.55} roughness={0.36} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('eccentric-shaft', props, [0.35, -0.16, 0.14])}>
        <Shaft length={0.9} radius={0.08} axis="z" color="#c3ccd8" />
        <mesh position={[0.34, 0, 0.16]}>
          <cylinderGeometry args={[0.13, 0.13, 0.18, 32]} />
          <meshStandardMaterial color="#ffb04c" metalness={0.78} roughness={0.24} />
        </mesh>
      </MachinePart>

      {['apex-seal-a', 'apex-seal-b', 'apex-seal-c'].map((id, index) => {
        const angle = (index / 3) * Math.PI * 2;
        return (
          <MachinePart
            key={id}
            {...partProps(id, props, [Math.cos(angle) * 0.32, Math.sin(angle) * 0.32, 0.2])}
            position={[Math.cos(angle) * APEX_RADIUS, Math.sin(angle) * APEX_RADIUS, 0.22]}
            rotation={[0, 0, angle + Math.PI / 2]}
          >
            <mesh castShadow>
              <boxGeometry args={[0.08, 0.32, 0.08]} />
              <meshStandardMaterial color="#f0d7a0" metalness={0.62} roughness={0.34} />
            </mesh>
          </MachinePart>
        );
      })}

      <MachinePart {...partProps('intake-port', props, [-0.46, -0.08, 0.08])} position={[-1.32, -0.48, 0.02]}>
        <mesh>
          <boxGeometry args={[0.42, 0.18, 0.16]} />
          <meshStandardMaterial color="#4c8dff" metalness={0.2} roughness={0.45} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('exhaust-port', props, [0.46, 0.08, 0.08])} position={[1.32, 0.48, 0.02]}>
        <mesh>
          <boxGeometry args={[0.42, 0.18, 0.16]} />
          <meshStandardMaterial color="#ff8a4c" metalness={0.2} roughness={0.45} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('spark-plug', props, [0.05, 0.4, 0.14])} position={[0.16, 1.28, 0.12]} rotation={[0, 0, -0.2]}>
        <mesh>
          <cylinderGeometry args={[0.045, 0.045, 0.38, 18]} />
          <meshStandardMaterial color="#f1f5ff" metalness={0.2} roughness={0.3} />
        </mesh>
        <mesh position={[0, -0.23, 0]}>
          <sphereGeometry args={[0.065, 22, 14]} />
          <meshStandardMaterial color="#ffb04c" emissive="#ff7a3c" emissiveIntensity={0.75} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('combustion-pocket', props, [0.22, 0.22, 0.18])} position={[0.54, 0.78, 0.18]}>
        <mesh>
          <sphereGeometry args={[0.28, 24, 16]} />
          <meshBasicMaterial color="#ff8a4c" transparent opacity={0.68} />
        </mesh>
      </MachinePart>

      <MachinePart {...partProps('intake-flow', props, [-0.5, -0.24, 0.16])} position={[-1.55, -0.74, 0.2]} rotation={[0, 0, 0.15]}>
        <FlowArrow color="#4c8dff" />
      </MachinePart>

      <MachinePart {...partProps('exhaust-flow', props, [0.5, 0.24, 0.16])} position={[1.55, 0.74, 0.2]} rotation={[0, 0, Math.PI + 0.15]}>
        <FlowArrow color="#ff8a4c" />
      </MachinePart>

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

export const wankelRotaryEngine: ProceduralMachineModule = {
  definition,
  animationModule: wankelRotaryEngineAnimation,
  Scene: WankelRotaryEngineScene,
};