import { Graphics, Rectangle, Text } from 'pixi.js';
import {
  asString,
  edgesInto,
  type Graph,
  type GraphNode,
  inlineInputs,
  inlineValue,
  type NodeCategory,
  type NodeDef,
  type PortDef,
  type PortType,
  type Value,
} from '../../core/graph';
import type { BehaviorAsset } from '../../core/model/Asset';
import type { Project } from '../../core/model/Project';
import type { PropertyValue } from '../../core/model/Properties';
import { assetRefLabel } from '../../core/properties/assetRef';
import type { PropertyDef } from '../../core/properties/PropertySchema';
import { formatNumber, Theme, textStyle, type TextStyleToken, truncate, Widget } from '../../ui';
import { keyLabel } from '../inspector/fieldFactory';

/** Node geometry in graph units; exported because edge anchors must land exactly on these ports. */
export const NODE_WIDTH = 176;
export const TITLE_HEIGHT = 24;
export const ROW_HEIGHT = 20;
export const PORT_RADIUS = 5;
/** Distance (graph units) within which a press counts as hitting a port. */
export const PORT_HIT_RADIUS = 9;
const PAD = 6;

export function categoryColor(category: NodeCategory): number {
  const c = Theme.colors;
  switch (category) {
    case 'event':
      return c.categoryEvent;
    case 'flow':
      return c.categoryFlow;
    case 'data':
      return c.categoryData;
    case 'variable':
      return c.categoryVariable;
    case 'action':
      return c.categoryAction;
  }
}

export function portColor(type: PortType): number {
  const c = Theme.colors;
  switch (type) {
    case 'exec':
      return c.portExec;
    case 'number':
      return c.portNumber;
    case 'boolean':
      return c.portBoolean;
    case 'string':
      return c.portString;
    case 'object':
      return c.portObject;
    case 'any':
      return c.portAny;
  }
}

export interface PortHit {
  port: PortDef;
  isOutput: boolean;
}

/** Draws one graph node entirely from its NodeDef; positioned in graph coordinates by GraphCanvas. */
export class NodeView extends Widget {
  private readonly box = new Graphics();
  private readonly ports = new Graphics();
  private readonly texts: Text[] = [];
  private paramLines: string[] = [];
  selected = false;
  hot = false;
  /** Data inputs that currently have a connection (their inline value is hidden). */
  private connected = new Set<string>();

  constructor(
    readonly node: GraphNode,
    readonly def: NodeDef,
  ) {
    super();
    this.cursor = 'grab';
    this.addChild(this.box, this.ports);
    this.sync(node, { nodes: [node], edges: [] }, null, null);
  }

  /** Ports sit on the left/right edges; widen the hit area so they can be grabbed. */
  override resize(w: number, h: number): void {
    super.resize(w, h);
    this.hitArea = new Rectangle(-PORT_HIT_RADIUS, 0, w + PORT_HIT_RADIUS * 2, h);
  }

  /** `project` resolves asset references (Spawn, Is asset). */
  sync(node: GraphNode, graph: Graph, asset: BehaviorAsset | null, project: Project | null): void {
    this.paramLines = this.def.params.map(
      (p) => `${p.label}: ${formatParam(p, node.params[p.key] ?? p.default, asset, project)}`,
    );
    this.connected = new Set(
      inlineInputs(this.def)
        .filter((p) => edgesInto(graph, node.id, p.key).length > 0)
        .map((p) => p.key),
    );
    const height =
      TITLE_HEIGHT + PAD + this.paramLines.length * ROW_HEIGHT + this.rowCount() * ROW_HEIGHT + PAD;
    this.rebuildTexts();
    this.resize(NODE_WIDTH, height);
    this.position.set(node.x, node.y);
  }

  private rowCount(): number {
    return Math.max(this.def.inputs.length, this.def.outputs.length);
  }

  /** Local position of a port's centre. */
  portPosition(key: string, isOutput: boolean): { x: number; y: number } | null {
    const list = isOutput ? this.def.outputs : this.def.inputs;
    const index = list.findIndex((p) => p.key === key);
    if (index < 0) return null;
    return { x: isOutput ? this.w : 0, y: this.rowY(index) };
  }

  private rowY(index: number): number {
    return TITLE_HEIGHT + PAD + this.paramLines.length * ROW_HEIGHT + index * ROW_HEIGHT + ROW_HEIGHT / 2;
  }

  /** Every port with its local centre – inputs on the left edge, outputs on the right. */
  private *portCentres(): Iterable<{ port: PortDef; isOutput: boolean; x: number; y: number }> {
    for (const [list, isOutput] of [
      [this.def.inputs, false],
      [this.def.outputs, true],
    ] as const) {
      for (let i = 0; i < list.length; i++)
        yield { port: list[i]!, isOutput, x: isOutput ? this.w : 0, y: this.rowY(i) };
    }
  }

  portAt(localX: number, localY: number): PortHit | null {
    for (const { port, isOutput, x, y } of this.portCentres()) {
      if (Math.hypot(localX - x, localY - y) <= PORT_HIT_RADIUS) return { port, isOutput };
    }
    return null;
  }

  private rebuildTexts(): void {
    for (const t of this.texts) t.destroy();
    this.texts.length = 0;
    const add = (
      text: string,
      style: TextStyleToken,
      x: number,
      y: number,
      align: 'left' | 'right' = 'left',
      maxWidth = NODE_WIDTH - PAD * 2,
    ) => {
      const node = new Text({ text: truncate(text, textStyle(style), maxWidth), style: textStyle(style) });
      node.position.set(align === 'left' ? x : x - node.width, y);
      this.addChild(node);
      this.texts.push(node);
    };
    add(this.def.label, 'accent', PAD + 2, (TITLE_HEIGHT - 16) / 2);
    let y = TITLE_HEIGHT + PAD;
    for (const line of this.paramLines) {
      add(line, 'small', PAD + 2, y + 2);
      y += ROW_HEIGHT;
    }
    for (let i = 0; i < this.rowCount(); i++) {
      const input = this.def.inputs[i];
      const output = this.def.outputs[i];
      const rowTop = y + i * ROW_HEIGHT + 2;
      if (input) {
        let label = input.label;
        if (input.type !== 'exec' && input.type !== 'object' && !this.connected.has(input.key)) {
          const value = inlineValue(this.node, input);
          if (value !== null && value !== '') label += `  ${formatValue(value)}`;
        }
        add(
          label,
          input.type === 'exec' ? 'body' : 'muted',
          PAD + PORT_RADIUS + 4,
          rowTop,
          'left',
          NODE_WIDTH / 2 + 20,
        );
      }
      if (output)
        add(
          output.label,
          output.type === 'exec' ? 'body' : 'muted',
          this.w - PAD - PORT_RADIUS - 4,
          rowTop,
          'right',
          NODE_WIDTH / 2 - 10,
        );
    }
  }

  override redraw(): void {
    const c = Theme.colors;
    this.box.clear();
    this.box.roundRect(2, 3, this.w, this.h, Theme.radius).fill({ color: 0x000000, alpha: 0.35 });
    this.box.roundRect(0, 0, this.w, this.h, Theme.radius).fill(c.node);
    this.box.roundRect(0, 0, this.w, TITLE_HEIGHT, Theme.radius).fill(categoryColor(this.def.category));
    this.box
      .rect(0, TITLE_HEIGHT - Theme.radius, this.w, Theme.radius)
      .fill(categoryColor(this.def.category));
    const border = this.hot ? c.hot : this.selected ? c.nodeSelected : c.nodeBorder;
    this.box
      .roundRect(0.5, 0.5, this.w - 1, this.h - 1, Theme.radius)
      .stroke({ width: this.selected || this.hot ? 2 : 1, color: border });

    this.ports.clear();
    const r = PORT_RADIUS;
    for (const { port, x, y } of this.portCentres()) {
      if (port.type === 'exec') {
        // A pentagon pointing right: the Blueprint-style exec pin.
        this.ports
          .moveTo(x - r, y - r)
          .lineTo(x + 1, y - r)
          .lineTo(x + r + 1, y)
          .lineTo(x + 1, y + r)
          .lineTo(x - r, y + r)
          .closePath()
          .fill(portColor('exec'));
      } else {
        this.ports.circle(x, y, r).fill(portColor(port.type));
        this.ports.circle(x, y, r).stroke({ width: 1, color: c.node });
      }
    }
  }
}

/** The value of a setting as shown on the node; references that no longer resolve get a "?". */
function formatParam(
  param: PropertyDef,
  value: PropertyValue | undefined,
  asset: BehaviorAsset | null,
  project: Project | null,
): string {
  if (value === undefined || value === '') return '—';
  if (param.kind === 'key') return keyLabel(String(value));
  if (param.kind === 'asset') return assetRefLabel(project, String(value));
  if (
    param.kind === 'enum' &&
    param.key === 'variable' &&
    asset &&
    !asset.variables.some((v) => v.key === value)
  )
    return `${value}?`;
  return formatValue(value);
}

function formatValue(value: Value): string {
  // Whole numbers stay bare to keep nodes narrow; fractions match the field that edits them.
  if (typeof value === 'number') return Number.isInteger(value) ? String(value) : formatNumber(value);
  if (typeof value === 'boolean') return value ? 'true' : 'false';
  return asString(value);
}