/**
 * The Variables node declares variables of the behavior around it as ports, rather than names of
 * its own. What that costs is the wiring – a port has to follow the variable it names when that is
 * renamed or swapped, and take its edges along, on the input side as well as on the output side.
 */
import { describe, expect, it } from 'vitest';
import { AddPortCommand, RepointPortCommand } from '../../src/core/commands/portCommands';
import {
  AddStructFieldCommand,
  AddVariableCommand,
  RemoveVariableCommand,
  RenameVariableCommand,
} from '../../src/core/commands/variableCommands';
import { type GraphNode, GraphInterpreter, NO_LOOKUP, resolveDef, VARIABLES } from '../../src/core/graph';
import type { BehaviorAsset } from '../../src/core/model/Asset';
import { graphLookup } from '../../src/core/model/graphLookup';
import { fakeContext, graphEditor, makeBehavior, makeProject, roundTrip } from '../helpers';

/** `px` and `py` are set in one node and read back in another, their sum landing in `sum`. */
function bothWays() {
  const fixture = makeProject();
  const behavior = makeBehavior(fixture, 'B', ['px', 'py', 'sum']);
  const edit = graphEditor(fixture, behavior);
  const start = edit.addNode('OnStart');
  const set = edit.variables(['px', 'py'], { write: true, params: { px: 7, py: 9 } });
  const get = edit.variables(['px', 'py']);
  const add = edit.addNode('Add');
  const store = edit.variables(['sum'], { write: true });
  edit.wire([
    [start, 'exec', set, 'exec'],
    [set, 'exec', store, 'exec'],
    [get, 'px', add, 'a'],
    [get, 'py', add, 'b'],
    [add, 'result', store, 'sum'],
  ]);
  return { fixture, behavior, set, get, store, edit };
}

function run(
  behavior: BehaviorAsset,
  fixture: ReturnType<typeof makeProject>,
  variables: Record<string, number> = { px: 0, py: 0, sum: 0 },
) {
  const interpreter = new GraphInterpreter(behavior.graph, graphLookup(fixture.project));
  const ctx = fakeContext({ variables });
  interpreter.fire('OnStart', ctx);
  return ctx.variables;
}

const portKeys = (behavior: BehaviorAsset, node: GraphNode, side: 'inputs' | 'outputs') =>
  resolveDef(node, behavior.graph, NO_LOOKUP)![side].map((p) => `${p.key}:${p.type}`);

describe('a node that reads or writes several variables at once', () => {
  it('writes each variable it names and reads each one back', () => {
    const { fixture, behavior } = bothWays();
    expect(run(behavior, fixture)).toEqual({ px: 7, py: 9, sum: 16 });
  });

  it('takes the port type from the variable, so a number output stays a number', () => {
    const { fixture, behavior, get, set } = bothWays();
    fixture.stack.execute(new AddVariableCommand(behavior.id, 'alive', 'boolean'));
    fixture.stack.execute(new AddPortCommand(behavior.id, get.id, { key: 'alive', kind: 'boolean' }));
    expect(portKeys(behavior, get, 'outputs')).toEqual(['px:number', 'py:number', 'alive:boolean']);
    expect(portKeys(behavior, set, 'inputs')).toEqual(['exec:exec', 'px:number', 'py:number']);
  });

  it('follows a renamed variable, edges and typed-in value on both sides', () => {
    const { fixture, behavior, get, set, store } = bothWays();
    fixture.stack.execute(new RenameVariableCommand(behavior.id, 'px', 'column'));
    fixture.stack.execute(new RenameVariableCommand(behavior.id, 'sum', 'total'));
    expect((get.ports ?? []).map((p) => p.key)).toEqual(['column', 'py']);
    expect(set.params).toEqual({ column: 7, py: 9 });
    expect(behavior.graph.edges.some((e) => e.from.node === get.id && e.from.port === 'column')).toBe(true);
    expect(behavior.graph.edges.some((e) => e.to.node === store.id && e.to.port === 'total')).toBe(true);
    expect(run(behavior, fixture, { column: 0, py: 0, total: 0 })).toEqual({ column: 7, py: 9, total: 16 });

    fixture.stack.undo();
    fixture.stack.undo();
    expect((get.ports ?? []).map((p) => p.key)).toEqual(['px', 'py']);
    expect(run(behavior, fixture)).toEqual({ px: 7, py: 9, sum: 16 });
  });

  it('keeps the edge when a port is pointed at another variable', () => {
    const { fixture, behavior, get } = bothWays();
    fixture.stack.execute(new AddVariableCommand(behavior.id, 'alive', 'boolean'));
    fixture.stack.execute(
      new RepointPortCommand(behavior.id, get.id, 'px', { key: 'alive', kind: 'boolean' }),
    );
    expect(portKeys(behavior, get, 'outputs')).toEqual(['alive:boolean', 'py:number']);
    expect(behavior.graph.edges.some((e) => e.from.node === get.id && e.from.port === 'alive')).toBe(true);

    fixture.stack.undo();
    expect(portKeys(behavior, get, 'outputs')).toEqual(['px:number', 'py:number']);
    expect(behavior.graph.edges.some((e) => e.from.node === get.id && e.from.port === 'px')).toBe(true);
  });

  it('keeps a port whose variable was removed, so undoing the removal restores the graph', () => {
    const { fixture, behavior, get } = bothWays();
    fixture.stack.execute(new RemoveVariableCommand(behavior.id, 'px'));
    // Left standing rather than dropped: taking the port would have to take its edge too, and
    // undo could not put either back. The inspector marks it as naming no variable.
    expect((get.ports ?? []).map((p) => p.key)).toEqual(['px', 'py']);

    fixture.stack.undo();
    expect(behavior.variables.map((v) => v.key)).toEqual(['px', 'py', 'sum']);
    expect(run(behavior, fixture)).toEqual({ px: 7, py: 9, sum: 16 });
  });

  it('survives a save and load, which is what makes the pick more than a session', () => {
    const { fixture, behavior } = bothWays();
    const loaded = roundTrip(fixture.project);
    const asset = loaded.assets.find((a) => a.id === behavior.id) as BehaviorAsset;
    const set = asset.graph.nodes.find((n) => n.type === VARIABLES && n.params.px === 7)!;
    expect(set.ports).toEqual([
      { key: 'px', kind: 'number', write: true },
      { key: 'py', kind: 'number', write: true },
    ]);
    expect(run(asset, { project: loaded, stack: fixture.stack })).toEqual({ px: 7, py: 9, sum: 16 });
  });

  /**
   * The bundle a struct port is handed is merged in, so a `Pack` of one field leaves the rest
   * standing. Tetris leans on this: each strand of `Next move` packs only the field it changes.
   */
  it('merges a partial bundle into a struct variable instead of replacing it', () => {
    const fixture = makeProject();
    const behavior = makeBehavior(fixture, 'B');
    fixture.stack.execute(new AddVariableCommand(behavior.id, 'piece', 'struct'));
    for (const key of ['shape', 'rot'])
      fixture.stack.execute(new AddStructFieldCommand(behavior.id, 'piece', { key, kind: 'number' }));
    const edit = graphEditor(fixture, behavior);
    const start = edit.addNode('OnStart');
    const set = edit.variables(['piece'], { write: true });
    const pack = edit.addNode('PackStruct', { rot: 2 });
    fixture.stack.execute(new AddPortCommand(behavior.id, pack.id, { key: 'rot', kind: 'number' }));
    edit.wire([
      [start, 'exec', set, 'exec'],
      [pack, 'value', set, 'piece'],
    ]);

    const ctx = fakeContext({ variables: { piece: { shape: 3, rot: 0 } } });
    new GraphInterpreter(behavior.graph, graphLookup(fixture.project)).fire('OnStart', ctx);
    expect(ctx.variables.piece).toEqual({ shape: 3, rot: 2 });
  });
});