import { describe, expect, it } from 'vitest';
import { CommandError } from '../../src/core/commands/Command';
import { AddNodeCommand, DisconnectCommand, RemoveNodeCommand, SetNodeParamCommand } from '../../src/core/commands/graphCommands';
import { AddVariableCommand, RemoveVariableCommand, RenameVariableCommand } from '../../src/core/commands/variableCommands';
import { GraphInterpreter, allNodeDefs, findNode, portsCompatible } from '../../src/core/graph';
import type { BehaviorAsset } from '../../src/core/model/Asset';
import { findAsset } from '../../src/core/model/Project';
import { deserializeProject, serializeProject } from '../../src/core/store/serialize';
import { type ProjectFixture, fakeContext, graphEditor, makeBehavior, makeProject, makeSpriteScene, place, roundTrip } from '../helpers';

/** Adds "On key held(ArrowRight) → Move(owner, dx = speed × dt)" to a project, built through commands like the editor would. */
function withMover<F extends ProjectFixture>(fixture: F) {
  const behavior = makeBehavior(fixture, 'Mover', ['speed']);
  const edit = graphEditor(fixture, behavior);
  const held = edit.addNode('OnKeyHeld', { key: 'ArrowRight' });
  const owner = edit.addNode('Owner');
  const speed = edit.addNode('GetVariable', { variable: 'speed' });
  const mul = edit.addNode('Multiply');
  const move = edit.addNode('Move');
  edit.wire([
    [held, 'exec', move, 'exec'],
    [owner, 'object', move, 'object'],
    [speed, 'value', mul, 'a'],
    [held, 'dt', mul, 'b'],
    [mul, 'result', move, 'dx'],
  ]);
  return { ...fixture, behavior, edit, nodes: { held, owner, speed, mul, move } };
}

/** A behavior "B" with the given number variables and an empty graph to edit. */
function emptyBehavior(variables: string[] = []) {
  const fixture = makeProject();
  const behavior = makeBehavior(fixture, 'B', variables);
  return { ...fixture, behavior, edit: graphEditor(fixture, behavior) };
}

describe('node registry', () => {
  it('registers the built-in node set with well-formed ports', () => {
    const defs = allNodeDefs();
    expect(defs.length).toBeGreaterThan(20);
    for (const def of defs) {
      const keys = [...def.inputs, ...def.outputs].map((p) => p.key);
      expect(new Set(def.inputs.map((p) => p.key)).size).toBe(def.inputs.length);
      expect(new Set(def.outputs.map((p) => p.key)).size).toBe(def.outputs.length);
      if (def.category === 'event') expect(def.inputs).toHaveLength(0);
      else expect(def.run).toBeTypeOf('function');
      expect(keys.every((k) => k.length > 0)).toBe(true);
    }
  });

  it('type-checks port connections', () => {
    expect(portsCompatible('exec', 'exec')).toBe(true);
    expect(portsCompatible('exec', 'number')).toBe(false);
    expect(portsCompatible('number', 'any')).toBe(true);
    expect(portsCompatible('any', 'boolean')).toBe(true);
    expect(portsCompatible('number', 'boolean')).toBe(false);
    expect(portsCompatible('object', 'object')).toBe(true);
  });
});

describe('GraphInterpreter', () => {
  it('runs an event pulse and pulls data lazily (speed × dt moves the owner)', () => {
    const { behavior } = withMover(makeProject());
    const interpreter = new GraphInterpreter(behavior.graph);
    const ctx = fakeContext({ variables: { speed: 100 } });
    const fired = interpreter.fire('OnKeyHeld', ctx, { dt: 0.5 }, (n) => n.params.key === 'ArrowRight');
    expect(fired).toBe(1);
    expect(ctx.owner!.x).toBe(50);
    expect(interpreter.fire('OnKeyHeld', ctx, { dt: 0.5 }, (n) => n.params.key === 'ArrowLeft')).toBe(0);
    expect(ctx.owner!.x).toBe(50);
  });

  it('uses inline values for unconnected inputs', () => {
    const { behavior, edit } = emptyBehavior();
    const start = edit.addNode('OnStart');
    const self = edit.addNode('Self');
    const move = edit.addNode('Move', { dx: 7, dy: -3 });
    edit.wire([[start, 'exec', move, 'exec'], [self, 'object', move, 'object']]);
    const ctx = fakeContext();
    new GraphInterpreter(behavior.graph).fire('OnStart', ctx);
    expect(ctx.self.x).toBe(7);
    expect(ctx.self.y).toBe(-3);
  });

  it('uses port defaults for unconnected inputs (Move scale = 1, Clamp 0…1)', () => {
    const { behavior, edit } = emptyBehavior();
    const start = edit.addNode('OnStart');
    const self = edit.addNode('Self');
    const clamp = edit.addNode('Clamp', { value: 5 });
    const move = edit.addNode('Move', { dx: 4 });
    edit.wire([[start, 'exec', move, 'exec'], [self, 'object', move, 'object'], [clamp, 'result', move, 'dy']]);
    const ctx = fakeContext();
    new GraphInterpreter(behavior.graph).fire('OnStart', ctx);
    expect(ctx.self.x).toBe(4); // scale defaulted to 1, not 0
    expect(ctx.self.y).toBe(1); // clamp(5, 0, 1)
  });

  it('five-node mover: Axis input → Move(dt from On update) moves speed × dt, diagonals normalized', () => {
    const { behavior, edit } = emptyBehavior(['speed']);
    const update = edit.addNode('OnUpdate');
    const owner = edit.addNode('Owner');
    const axis = edit.addNode('AxisInput');
    const speed = edit.addNode('GetVariable', { variable: 'speed' });
    const move = edit.addNode('Move');
    edit.wire([
      [update, 'exec', move, 'exec'],
      [update, 'dt', move, 'dt'],
      [owner, 'object', move, 'object'],
      [axis, 'x', move, 'dx'],
      [axis, 'y', move, 'dy'],
      [speed, 'value', move, 'scale'],
    ]);
    expect(behavior.graph.nodes).toHaveLength(5);

    const interpreter = new GraphInterpreter(behavior.graph);
    const run = (keys: string[]) => {
      const ctx = fakeContext({ variables: { speed: 100 }, dt: 0.5, isKeyDown: (k) => keys.includes(k) });
      interpreter.fire('OnUpdate', ctx, { dt: 0.5 });
      return { x: ctx.owner!.x, y: ctx.owner!.y };
    };
    expect(run([])).toEqual({ x: 0, y: 0 });
    expect(run(['ArrowRight'])).toEqual({ x: 50, y: 0 });
    expect(run(['ArrowLeft'])).toEqual({ x: -50, y: 0 });
    expect(run(['ArrowUp'])).toEqual({ x: 0, y: -50 });
    const diagonal = run(['ArrowLeft', 'ArrowUp']);
    expect(Math.hypot(diagonal.x, diagonal.y)).toBeCloseTo(50, 6); // same distance as a straight move
    expect(diagonal.x).toBeCloseTo(-50 / Math.SQRT2, 6);
    expect(diagonal.y).toBeCloseTo(-50 / Math.SQRT2, 6);
    expect(run(['ArrowLeft', 'ArrowRight'])).toEqual({ x: 0, y: 0 }); // opposite keys cancel
  });

  it('vector and math helpers', () => {
    const { behavior, edit } = emptyBehavior();
    const start = edit.addNode('OnStart');
    const sources = [
      edit.addNode('Normalize', { x: 3, y: 4 }),
      edit.addNode('Length', { x: 3, y: 4 }),
      edit.addNode('Sqrt', { value: 16 }),
      edit.addNode('Abs', { value: -2 }),
      edit.addNode('Min', { a: 3, b: -1 }),
      edit.addNode('Max', { a: 3, b: -1 }),
    ];
    const ports = ['x', 'result', 'result', 'result', 'result', 'result'];
    // One Log per source, chained after On start.
    let previous = start;
    sources.forEach((source, i) => {
      const log = edit.addNode('Log');
      edit.wire([[previous, 'exec', log, 'exec'], [source, ports[i]!, log, 'message']]);
      previous = log;
    });
    const ctx = fakeContext();
    new GraphInterpreter(behavior.graph).fire('OnStart', ctx);
    expect(ctx.logs).toEqual(['0.6', '5', '4', '2', '-1', '3']);
  });

  it('follows Branch, writes variables and logs', () => {
    const { behavior, edit } = emptyBehavior(['count']);
    const start = edit.addNode('OnStart');
    const get = edit.addNode('GetVariable', { variable: 'count' });
    const cmp = edit.addNode('Compare', { op: '<', b: 3 });
    const branch = edit.addNode('Branch');
    const add = edit.addNode('Add', { b: 1 });
    const set = edit.addNode('SetVariable', { variable: 'count' });
    const logThen = edit.addNode('Log', { message: 'then' });
    const logElse = edit.addNode('Log', { message: 'else' });
    edit.wire([
      [start, 'exec', branch, 'exec'],
      [get, 'value', cmp, 'a'],
      [cmp, 'result', branch, 'condition'],
      [branch, 'then', set, 'exec'],
      [get, 'value', add, 'a'],
      [add, 'result', set, 'value'],
      [set, 'exec', logThen, 'exec'],
      [branch, 'else', logElse, 'exec'],
    ]);

    const interpreter = new GraphInterpreter(behavior.graph);
    const ctx = fakeContext({ variables: { count: 0 } });
    for (let i = 0; i < 5; i++) interpreter.fire('OnStart', ctx);
    expect(ctx.variables.count).toBe(3);
    expect(ctx.logs).toEqual(['then', 'then', 'then', 'else', 'else']);
  });

  it('reports traversed edges and nodes to the trace listener', () => {
    const { behavior, nodes } = withMover(makeProject());
    const interpreter = new GraphInterpreter(behavior.graph);
    const edges: string[] = [];
    const visited: string[] = [];
    interpreter.trace = { onEdge: (id) => edges.push(id), onNode: (id) => visited.push(id) };
    interpreter.fire('OnKeyHeld', fakeContext(), { dt: 1 });
    expect(edges).toHaveLength(1);
    expect(visited).toContain(nodes.mul.id);
    expect(visited).toContain(nodes.move.id);
  });

  it('stops a runaway flow instead of hanging', () => {
    const { behavior, edit } = emptyBehavior();
    const start = edit.addNode('OnStart');
    const a = edit.addNode('Sequence');
    const b = edit.addNode('Sequence');
    edit.wire([[start, 'exec', a, 'exec'], [a, 'a', b, 'exec'], [b, 'a', a, 'exec']]);
    expect(() => new GraphInterpreter(behavior.graph).fire('OnStart', fakeContext())).toThrow(/step limit/);
  });
});

describe('graph commands', () => {
  it('rejects incompatible, self and duplicate connections', () => {
    const { edit, nodes: { held, mul, move } } = withMover(makeProject());
    expect(() => edit.connect(held, 'exec', mul, 'a')).toThrow(/Cannot connect/);
    expect(() => edit.connect(mul, 'result', mul, 'a')).toThrow(/itself/);
    expect(() => edit.connect(held, 'exec', move, 'exec')).toThrow(/Already/);
    expect(() => edit.connect(held, 'nope', move, 'exec')).toThrow(/Port/);
  });

  it('replaces the edge of a data input and restores it on undo', () => {
    const { behavior, stack, edit, nodes } = withMover(makeProject());
    const literal = edit.addNode('Number', { value: 9 });
    const before = behavior.graph.edges.length;
    edit.connect(literal, 'value', nodes.move, 'dx');
    expect(behavior.graph.edges.length).toBe(before); // one replaced, one added
    const sourceOfDx = () => behavior.graph.edges.find((e) => e.to.node === nodes.move.id && e.to.port === 'dx')!.from.node;
    expect(sourceOfDx()).toBe(literal.id);
    stack.undo();
    expect(sourceOfDx()).toBe(nodes.mul.id);
  });

  it('removing a node drops its edges; undo restores both', () => {
    const { behavior, stack, nodes } = withMover(makeProject());
    const edgesBefore = behavior.graph.edges.length;
    stack.execute(new RemoveNodeCommand(behavior.id, nodes.mul.id));
    expect(findNode(behavior.graph, nodes.mul.id)).toBeUndefined();
    expect(behavior.graph.edges.length).toBe(edgesBefore - 3);
    stack.undo();
    expect(findNode(behavior.graph, nodes.mul.id)).toBeDefined();
    expect(behavior.graph.edges.length).toBe(edgesBefore);
    stack.execute(new DisconnectCommand(behavior.id, behavior.graph.edges[0]!.id));
    expect(behavior.graph.edges.length).toBe(edgesBefore - 1);
    stack.undo();
    expect(behavior.graph.edges.length).toBe(edgesBefore);
  });

  it('coerces declared params and keeps inline input values', () => {
    const { behavior, stack, nodes } = withMover(makeProject());
    stack.execute(new SetNodeParamCommand(behavior.id, nodes.held.id, 'key', 'ArrowLeft'));
    stack.execute(new SetNodeParamCommand(behavior.id, nodes.move.id, 'dy', 4));
    const held = findNode(behavior.graph, nodes.held.id)!;
    const move = findNode(behavior.graph, nodes.move.id)!;
    expect(held.params.key).toBe('ArrowLeft');
    expect(move.params.dy).toBe(4);
    stack.undo();
    expect(move.params.dy).toBeUndefined();
  });
});

describe('variable commands', () => {
  it('adds, renames (including graph references and overrides) and removes variables', () => {
    const f = withMover(makeSpriteScene());
    const { behavior, stack, nodes, object } = f;
    const logic = place(f, behavior.id, { x: 0, y: 0 });
    object(logic).overrides.speed = 5;

    stack.execute(new RenameVariableCommand(behavior.id, 'speed', 'velocity'));
    expect(behavior.variables[0]!.key).toBe('velocity');
    expect(behavior.props).toEqual({ enabled: true, velocity: 0 });
    expect(object(logic).overrides).toEqual({ velocity: 5 });
    expect(findNode(behavior.graph, nodes.speed.id)!.params.variable).toBe('velocity');
    stack.undo();
    expect(behavior.variables[0]!.key).toBe('speed');
    expect(object(logic).overrides).toEqual({ speed: 5 });

    expect(() => stack.execute(new AddVariableCommand(behavior.id, 'speed', 'number'))).toThrow(/already/);
    expect(() => stack.execute(new AddVariableCommand(behavior.id, '1bad', 'number'))).toThrow(/names/);

    stack.execute(new RemoveVariableCommand(behavior.id, 'speed'));
    expect(behavior.variables).toHaveLength(0);
    expect(object(logic).overrides).toEqual({});
    stack.undo();
    expect(behavior.variables).toHaveLength(1);
    expect(object(logic).overrides).toEqual({ speed: 5 });
  });
});

describe('behavior serialization', () => {
  it('round-trips variables and graph, dropping unknown node types and dangling edges', () => {
    const { project, behavior } = withMover(makeProject());
    const loaded = findAsset(roundTrip(project), behavior.id) as BehaviorAsset;
    expect(loaded.variables).toEqual(behavior.variables);
    expect(loaded.graph).toEqual(behavior.graph);
    expect(loaded.props).toEqual({ enabled: true, speed: 0 });

    const raw = serializeProject(project) as { assets: { id: string; graph?: { nodes: unknown[]; edges: unknown[] } }[] };
    const rawGraph = raw.assets.find((a) => a.id === behavior.id)!.graph!;
    rawGraph.nodes.push({ id: 'zzz', type: 'DoesNotExist', x: 0, y: 0, params: {} });
    rawGraph.edges.push({ id: 'e-bad', from: { node: 'zzz', port: 'exec' }, to: { node: behavior.graph.nodes[0]!.id, port: 'exec' } });
    const cleaned = findAsset(deserializeProject(raw), behavior.id) as BehaviorAsset;
    expect(cleaned.graph.nodes.length).toBe(behavior.graph.nodes.length);
    expect(cleaned.graph.edges.length).toBe(behavior.graph.edges.length);
  });
});

describe('unknown node types', () => {
  it('are rejected as a CommandError by execute, not thrown from the constructor', () => {
    const fixture = makeProject();
    const behavior = makeBehavior(fixture, 'B');
    // Building the command must not throw: callers construct it outside the editor's
    // error handling (`state.execute(new AddNodeCommand(…))`), so a throw here would crash.
    const command = new AddNodeCommand(behavior.id, 'DoesNotExist', 0, 0);
    expect(command.label).toBe('Add DoesNotExist');
    expect(() => command.execute(fixture.project)).toThrow(CommandError);
    expect(behavior.graph.nodes).toHaveLength(0);
  });
});