import {
  AddPortCommand,
  AddPortsCommand,
  nextPortName,
  RemovePortCommand,
  RenamePortCommand,
  RepointPortCommand,
  SetPortWriteCommand,
} from '../../core/commands/portCommands';
import {
  BEHAVIOR_START,
  DECLARED_PORT_KINDS,
  type DeclaredPort,
  type GraphNode,
  isTerminalNode,
  missingFieldPorts,
  OBJECT_BEHAVIOR_PARAM,
  OBJECT_BEHAVIOR_SETTING,
  OBJECT_TYPE_SETTING,
  portKindOf,
  propertyTargetOf,
  structShapeOf,
  targetLabel,
  targetProperties,
} from '../../core/graph';
import { findAssetOf } from '../../core/model/Project';
import { textOf } from '../../core/model/Properties';
import { type PropertyDef, schemaForAsset, VARIABLE_KINDS } from '../../core/properties/PropertySchema';
import {
  Checkbox,
  Dropdown,
  HStack,
  Label,
  Menu,
  type MenuItem,
  Spacer,
  TextField,
  Theme,
  type Widget,
} from '../../ui';
import { NAME_WIDTH, removeButton } from './fieldFactory';
import { addNote, type InspectorHost } from './host';
import { KIND_LABELS, kindMark, markLabel } from './variableRows';

/**
 * The ports of a Variables node: each one *is* a variable of the behavior, so it is picked from that
 * list rather than named, and its kind follows the variable's declaration. Set makes it written too.
 */
export function buildVariablePortSection(
  host: InspectorHost,
  assetId: string,
  node: GraphNode,
  variables: readonly PropertyDef[],
): void {
  buildPickedPortSection(host, assetId, node, {
    noun: 'Variable',
    choices: variables,
    owner: 'this behavior',
    empty: 'This behavior has no variables yet.',
  });
}

/** The type decides what the ports are picked from; Any names them by hand, with a kind picked. */
export function buildPropertyPortSection(
  host: InspectorHost,
  assetId: string,
  node: GraphNode,
  addSetting: (def: PropertyDef) => void,
): void {
  const target = propertyTargetOf(node.params);
  addSetting(OBJECT_TYPE_SETTING);
  if (target === 'any') {
    buildPickedPortSection(host, assetId, node, { noun: 'Property', choices: [], owner: '', custom: true });
    return;
  }
  if (target !== 'behavior') {
    const owner = `a ${targetLabel(target)}`;
    buildPickedPortSection(host, assetId, node, {
      noun: 'Property',
      choices: targetProperties(target),
      owner,
    });
    return;
  }
  addSetting(OBJECT_BEHAVIOR_SETTING);
  const id = textOf(node.params[OBJECT_BEHAVIOR_PARAM] ?? '');
  const behavior = id ? findAssetOf(host.state.project, id, 'behavior') : undefined;
  buildPickedPortSection(host, assetId, node, {
    noun: 'Property',
    choices: behavior ? schemaForAsset(behavior) : [],
    owner: behavior ? `"${behavior.name}"` : 'a behavior',
    empty: id ? 'That behavior is gone.' : 'Pick a behavior first.',
  });
}

interface PickedPorts {
  noun: 'Variable' | 'Property';
  choices: readonly PropertyDef[];
  /** Whose ports these are, for the warning on one it does not have. */
  owner: string;
  empty?: string;
  /** Named by hand instead of picked. */
  custom?: boolean;
}

function buildPickedPortSection(
  host: InspectorHost,
  assetId: string,
  node: GraphNode,
  { noun, choices, owner, empty, custom = false }: PickedPorts,
): void {
  const plural = noun === 'Property' ? 'properties' : 'variables';
  const ports = node.ports ?? [];
  const taken = new Set(ports.map((p) => p.key));
  const portOf = (def: PropertyDef): DeclaredPort => ({ key: def.key, kind: portKindOf(def) });
  const pick = (own: string, onPick: (port: DeclaredPort) => void): MenuItem[] =>
    choices.map((def) => ({
      label: def.key,
      disabled: taken.has(def.key) && def.key !== own,
      onSelect: () => onPick(portOf(def)),
    }));
  const typed = (): MenuItem[] =>
    VARIABLE_KINDS.map((kind) => ({
      label: KIND_LABELS[kind],
      onSelect: () =>
        host.state.execute(
          new AddPortCommand(assetId, node.id, { key: nextPortName(node, noun.toLowerCase()), kind }),
        ),
    }));
  const searchable = noun === 'Property';

  const header = new HStack({ gap: Theme.gap, align: 'center' });
  header.add(new Label(plural.toUpperCase(), { style: 'title' }), 1);
  const add = new Dropdown(`+ ${noun}`, { variant: 'ghost' });
  add.onClick = () => {
    const items = pick('', (port) => host.state.execute(new AddPortCommand(assetId, node.id, port)));
    new Menu(custom ? typed() : items, { searchable }).openBelow(add);
  };
  add.setEnabled(custom || choices.some((def) => !taken.has(def.key)));
  header.add(add);
  host.body.add(header);

  if (!custom && choices.length === 0 && empty) addNote(host, empty);
  else if (ports.length === 0) addNote(host, `No ${plural} picked yet. Each one adds a port.`);

  for (const port of ports) {
    const toggle = writeToggle(host, assetId, node, port);
    if (custom) {
      const name = new TextField(port.key, {
        width: NAME_WIDTH,
        onChange: (next) =>
          host.state.execute(new RenamePortCommand(assetId, node.id, port.key, next.trim())),
      });
      portRow(host, assetId, node, port, name, toggle);
      continue;
    }
    const def = choices.find((d) => d.key === port.key);
    const known = def !== undefined && portKindOf(def) === port.kind;
    const choose = new Dropdown(port.key, { variant: known ? 'default' : 'danger' });
    choose.onClick = () => {
      const items = pick(port.key, (next) =>
        host.state.execute(new RepointPortCommand(assetId, node.id, port.key, next)),
      );
      new Menu(items, { searchable }).openBelow(choose);
    };
    portRow(host, assetId, node, port, choose, toggle);
    if (!known) addNote(host, `"${port.key}" is not a ${noun.toLowerCase()} of ${owner}.`, 'warning');
  }
}

/**
 * The ports a node declares for itself: the signature of a behavior seen as a node, or the fields
 * of a struct. A start node's are named from the caller's side – what it hands into the graph is
 * an *input* of the behavior – which is why the side comes from the node type, not from here.
 */
export function buildPortSection(
  host: InspectorHost,
  assetId: string,
  node: GraphNode,
  variables: readonly PropertyDef[] = [],
): void {
  const onStart = node.type === BEHAVIOR_START;
  const noun = isTerminalNode(node) ? (onStart ? 'Input' : 'Output') : 'Field';
  const base = noun === 'Field' ? 'field' : onStart ? 'in' : 'out';

  const header = new HStack({ gap: Theme.gap, align: 'center' });
  header.add(new Label(`${noun.toUpperCase()}S`, { style: 'title' }), 1);
  if (noun === 'Field') addShapePicker(host, assetId, node, variables, header);
  const add = new Dropdown(`+ ${noun}`, { variant: 'ghost' });
  add.onClick = () => {
    const items = DECLARED_PORT_KINDS.map((kind) => ({
      label: KIND_LABELS[kind],
      onSelect: () =>
        host.state.execute(new AddPortCommand(assetId, node.id, { key: nextPortName(node, base), kind })),
    }));
    new Menu(items).openBelow(add);
  };
  header.add(add);
  host.body.add(header);

  const ports = node.ports ?? [];
  if (ports.length === 0)
    addNote(
      host,
      noun === 'Field'
        ? 'No fields yet. Every field added here becomes a port of the struct.'
        : onStart
          ? 'No inputs yet. Every input added here becomes a port on the node that runs this behavior.'
          : 'No outputs yet. Every output added here becomes a result of running this behavior.',
    );

  for (const port of ports) {
    const name = new TextField(port.key, {
      width: NAME_WIDTH,
      onChange: (next) => host.state.execute(new RenamePortCommand(assetId, node.id, port.key, next.trim())),
    });
    portRow(host, assetId, node, port, name);
  }
}

function writeToggle(host: InspectorHost, assetId: string, node: GraphNode, port: DeclaredPort): Widget[] {
  const box = new Checkbox(port.write === true);
  box.onChange = (on) => host.state.execute(new SetPortWriteCommand(assetId, node.id, port.key, on));
  return [new Label('Set', { style: 'muted' }), box];
}

function portRow(
  host: InspectorHost,
  assetId: string,
  node: GraphNode,
  port: DeclaredPort,
  name: Widget,
  extras: readonly Widget[] = [],
): void {
  const row = new HStack({ gap: Theme.gap, align: 'center' });
  row.minHeight = Theme.rowHeight;
  row.add(markLabel(kindMark(port.kind)));
  row.add(name, 1);
  for (const extra of extras) row.add(extra);
  row.add(new Spacer());
  row.add(removeButton(() => host.state.execute(new RemovePortCommand(assetId, node.id, port.key))));
  host.body.add(row);
}

/**
 * Takes the fields of a Pack/Expand from a variable that already declares the shape, instead of
 * typing them again. Only offered where there is a shape to copy; a field the node already has
 * stays as it is, so this adds and never rewrites.
 */
function addShapePicker(
  host: InspectorHost,
  assetId: string,
  node: GraphNode,
  variables: readonly PropertyDef[],
  header: HStack,
): void {
  const shaped = variables.filter((v) => structShapeOf(v) !== undefined);
  if (shaped.length === 0) return;

  const pick = new Dropdown('From variable', { variant: 'ghost' });
  pick.onClick = () => {
    const items: MenuItem[] = shaped.map((v) => {
      const ports = missingFieldPorts(node, structShapeOf(v) ?? []);
      return {
        label: v.kind === 'list' ? `${v.key} (item)` : v.key,
        disabled: ports.length === 0,
        onSelect: () => host.state.execute(new AddPortsCommand(assetId, node.id, ports)),
      };
    });
    new Menu(items).openBelow(pick);
  };
  header.add(pick);
}