import { describe, expect, it } from 'vitest';
import { CommandError } from '../../src/core/commands/Command';
import { ConnectCommand, FoldEdgeCommand } from '../../src/core/commands/graphCommands';
import { GraphInterpreter } 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 {
  buildFoldMarks,
  foldedEdgeShown,
  type FoldMarkEnd,
  foldMarkAt,
  foldMarkKey,
  foldMarkLabel,
  foldMarkRadius,
} from '../../src/editor/graph/folding';
import { fakeContext, graphEditor, makeBehavior, makeProject, roundTrip } from '../helpers';

/** "On start → Move(self, dx = 7)": two edges, so a fold can hide one and leave the other. */
function mover() {
  const fixture = makeProject();
  const behavior = makeBehavior(fixture, 'Mover');
  const edit = graphEditor(fixture, behavior);
  const start = edit.addNode('OnStart');
  const self = edit.addNode('Self');
  const move = edit.addNode('Move', { dx: 7 });
  edit.wire([
    [start, 'exec', move, 'exec'],
    [self, 'object', move, 'object'],
  ]);
  return { ...fixture, behavior, edit, nodes: { start, self, move } };
}

describe('folding an edge', () => {
  it('changes nothing about what the graph does – the value still arrives', () => {
    const { project, stack, behavior } = mover();
    for (const edge of behavior.graph.edges) stack.execute(new FoldEdgeCommand(behavior.id, edge.id, true));
    expect(behavior.graph.edges.every((e) => e.folded === true)).toBe(true);

    const ctx = fakeContext();
    new GraphInterpreter(behavior.graph).fire('OnStart', ctx);
    expect(ctx.self.x).toBe(7);
    // And the edges themselves are untouched apart from the flag.
    expect(findAsset(project, behavior.id)).toBe(behavior);
    expect(behavior.graph.edges).toHaveLength(2);
  });

  it('survives the save, and unfolding leaves no trace in the file', () => {
    const { project, stack, behavior } = mover();
    const [first, second] = behavior.graph.edges;
    stack.execute(new FoldEdgeCommand(behavior.id, first!.id, true));

    const loaded = findAsset(roundTrip(project), behavior.id) as BehaviorAsset;
    expect(loaded.graph.edges.find((e) => e.id === first!.id)!.folded).toBe(true);
    expect('folded' in loaded.graph.edges.find((e) => e.id === second!.id)!).toBe(false);

    stack.execute(new FoldEdgeCommand(behavior.id, first!.id, false));
    const again = findAsset(roundTrip(project), behavior.id) as BehaviorAsset;
    expect(again.graph.edges.every((e) => !('folded' in e))).toBe(true);
  });

  it('is undoable, and undo restores the state the edge really had', () => {
    const { stack, behavior } = mover();
    const edge = behavior.graph.edges[0]!;
    stack.execute(new FoldEdgeCommand(behavior.id, edge.id, true));
    // Folding an already folded edge must not make undo unfold it.
    stack.execute(new FoldEdgeCommand(behavior.id, edge.id, true));
    stack.undo();
    expect(edge.folded).toBe(true);
    stack.undo();
    expect(edge.folded).toBeUndefined();
  });

  it('reports a missing edge as a CommandError instead of throwing from the constructor', () => {
    const { project, behavior } = mover();
    const command = new FoldEdgeCommand(behavior.id, 'no-such-edge', true);
    expect(command.label).toBe('Hide link');
    expect(() => command.execute(project)).toThrow(CommandError);
  });

  it('belongs to the edge, not to the port: a replacement starts out shown', () => {
    const { stack, behavior, edit, nodes } = mover();
    const edge = behavior.graph.edges.find((e) => e.to.port === 'object')!;
    stack.execute(new FoldEdgeCommand(behavior.id, edge.id, true));

    const owner = edit.addNode('Owner');
    stack.execute(
      new ConnectCommand(
        behavior.id,
        { node: owner.id, port: 'object' },
        { node: nodes.move.id, port: 'object' },
      ),
    );
    const now = behavior.graph.edges.find((e) => e.to.port === 'object')!;
    expect(now.id).not.toBe(edge.id);
    expect(now.folded).toBeUndefined();
    // Undo puts the old edge back exactly as it was – folded.
    stack.undo();
    expect(behavior.graph.edges.find((e) => e.to.port === 'object')!.folded).toBe(true);
  });

  it('ignores a folded flag in the file that is not literally true', () => {
    const { project, behavior } = mover();
    const raw = serializeProject(project) as {
      assets: { id: string; graph?: { edges: Record<string, unknown>[] } }[];
    };
    const edges = raw.assets.find((a) => a.id === behavior.id)!.graph!.edges;
    edges[0]!.folded = 'yes';
    edges[1]!.folded = false;
    const loaded = findAsset(deserializeProject(raw), behavior.id) as BehaviorAsset;
    expect(loaded.graph.edges.every((e) => !('folded' in e))).toBe(true);
  });
});

describe('when a folded edge shows its curve anyway', () => {
  const edge = { id: 'e', from: { node: 'a', port: 'out' }, to: { node: 'b', port: 'in' } };

  it('stays hidden while neither end is selected', () => {
    expect(foldedEdgeShown(edge, new Set(['c']), false)).toBe(false);
    expect(foldedEdgeShown(edge, new Set(), false)).toBe(false);
  });

  it('comes back for either end, not just the source', () => {
    expect(foldedEdgeShown(edge, new Set(['a']), false)).toBe(true);
    expect(foldedEdgeShown(edge, new Set(['b']), false)).toBe(true);
  });

  it('always shows while a pulse is on it, so the live trace keeps its thread', () => {
    expect(foldedEdgeShown(edge, new Set(), true)).toBe(true);
  });
});

describe('several hidden links at one port', () => {
  it('share a mark, while a different port or side gets its own', () => {
    const out = foldMarkKey({ node: 'a', port: 'value' }, true);
    expect(foldMarkKey({ node: 'a', port: 'value' }, true)).toBe(out);
    expect(foldMarkKey({ node: 'a', port: 'other' }, true)).not.toBe(out);
    expect(foldMarkKey({ node: 'b', port: 'value' }, true)).not.toBe(out);
    // The same port on the other side of the node is a mark of its own.
    expect(foldMarkKey({ node: 'a', port: 'value' }, false)).not.toBe(out);
  });

  it('cannot be confused by a node or port name that contains the separator', () => {
    expect(foldMarkKey({ node: 'a b', port: 'c' }, true)).not.toBe(
      foldMarkKey({ node: 'a', port: 'b c' }, true),
    );
  });

  it('name one far node and count the rest, so nothing is written on top of anything', () => {
    expect(foldMarkLabel(['Add'])).toBe('Add');
    expect(foldMarkLabel(['Add', 'Compare'])).toBe('Add +1');
    expect(foldMarkLabel(['Add', 'Compare', 'Multiply'])).toBe('Add +2');
    expect(foldMarkLabel([])).toBe('');
  });
});

/** The bundling that keeps two hidden links out of the same port from stacking on one pixel. */
describe('fold mark bundling', () => {
  const end = (over: Partial<FoldMarkEnd> & { edgeId: string; key: string }): FoldMarkEnd => ({
    other: 'far',
    otherLabel: 'Far',
    isOutput: true,
    portX: 100,
    portY: 50,
    color: 1,
    hot: false,
    ...over,
  });

  it('gives one port one mark, however many links it hides', () => {
    const marks = buildFoldMarks(
      [
        end({ edgeId: 'e1', key: 'a', other: 'n1', otherLabel: 'Add' }),
        end({ edgeId: 'e2', key: 'a', other: 'n2', otherLabel: 'Compare' }),
        end({ edgeId: 'e3', key: 'b', other: 'n3', otherLabel: 'Move' }),
      ],
      16,
    );
    expect(marks).toHaveLength(2);
    expect(marks[0]!.edgeIds).toEqual(['e1', 'e2']);
    expect(foldMarkLabel(marks[0]!.names)).toBe('Add +1');
    expect(marks[1]!.edgeIds).toEqual(['e3']);
  });

  it('dedupes the far nodes, so two links to one node select it once', () => {
    const marks = buildFoldMarks(
      [end({ edgeId: 'e1', key: 'a', other: 'n1' }), end({ edgeId: 'e2', key: 'a', other: 'n1' })],
      16,
    );
    expect(marks[0]!.others).toEqual(['n1']);
  });

  it('puts the mark a stub out of its port, on the side the port faces', () => {
    const [out] = buildFoldMarks([end({ edgeId: 'e1', key: 'a', isOutput: true })], 16);
    const [into] = buildFoldMarks([end({ edgeId: 'e2', key: 'b', isOutput: false })], 16);
    expect(out!.x).toBe(116);
    expect(into!.x).toBe(84);
  });

  it('lets a pulse anywhere in the bundle colour the whole mark', () => {
    const marks = buildFoldMarks(
      [
        end({ edgeId: 'e1', key: 'a', color: 1, hot: false }),
        end({ edgeId: 'e2', key: 'a', color: 9, hot: true }),
      ],
      16,
    );
    expect(marks[0]!.hot).toBe(true);
    expect(marks[0]!.color).toBe(9);
  });

  it('grows the dot for a bundle and finds it under a click', () => {
    expect(foldMarkRadius(1, 5)).toBe(5);
    expect(foldMarkRadius(2, 5)).toBe(7);
    const marks = [{ edgeIds: ['e1', 'e2'], x: 100, y: 50 }];
    expect(foldMarkAt(marks, { x: 108, y: 50 }, 5)).toBe(marks[0]);
    expect(foldMarkAt(marks, { x: 120, y: 50 }, 5)).toBeNull();
  });
});