import {
  FacadeHandlerError, FacadeRequest, FacadeResponse, FacadeSerialQueue, createRequest, isFacadeRequest,
} from "./facade-envelope.js";

export const TECHDRAW_SCHEMA = "freecad-web-techdraw/frontend-drawing/v1" as const;
export const TECHDRAW_COMMAND = "techdraw.createRecompute" as const;
export interface TechDrawBox { length: number; width: number; height: number }
export interface TechDrawPayload {
  schema: typeof TECHDRAW_SCHEMA;
  module: "TechDraw";
  action: "create/recompute";
  documentId?: string;
  box?: TechDrawBox;
}
export const TECHDRAW_FIXTURE: TechDrawPayload = {
  schema: TECHDRAW_SCHEMA, module: "TechDraw", action: "create/recompute",
  box: { length: 40, width: 24, height: 18 },
};
export interface TechDrawResult {
  schema: typeof TECHDRAW_SCHEMA;
  module: "TechDraw";
  action: "create/recompute";
  source: "freecad-source";
  box: TechDrawBox;
  volume: number;
  renderer: "TechDraw.viewPartAsSvg";
  nativeSource: "TechDraw::DrawViewPart";
  svg: string;
  bounds: [number, number, number, number];
  edgeCount: number;
  document: { name: string; objectCount: number; keptOpen: true };
  page: string;
  pageSize: [number, number];
  view: string;
}
export interface TechDrawKernel {
  ccall(name: string, type: "number" | "string", argTypes?: string[], args?: unknown[]): number | string;
}
export type TechDrawRequest = FacadeRequest<TechDrawPayload>;
export type TechDrawResponse = FacadeResponse<TechDrawResult>;

export function createTechDrawRequest(id: string, payload: TechDrawPayload = TECHDRAW_FIXTURE): TechDrawRequest {
  return createRequest(id, TECHDRAW_COMMAND, payload, payload.documentId ?? "TechDrawDrawing");
}
export function isTechDrawRequest(value: unknown): value is TechDrawRequest {
  if (!isFacadeRequest(value)) return false;
  const request = value as TechDrawRequest;
  const p = request.payload;
  return request.command === TECHDRAW_COMMAND && p?.schema === TECHDRAW_SCHEMA
    && p.module === "TechDraw" && p.action === "create/recompute"
    && (p.documentId === undefined || typeof p.documentId === "string")
    && (p.box === undefined || (typeof p.box?.length === "number" && typeof p.box?.width === "number" && typeof p.box?.height === "number"));
}
export async function handleTechDraw(p: TechDrawPayload, signal: AbortSignal, source: TechDrawKernel | Promise<TechDrawKernel>): Promise<TechDrawResult> {
  if (signal.aborted) throw new FacadeHandlerError("cancelled", "request was cancelled");
  if (!isTechDrawRequest(createTechDrawRequest("validation", p))
    || (p.box && ![p.box.length, p.box.width, p.box.height].every(value => Number.isFinite(value) && value > 0)))
    throw new FacadeHandlerError("invalid_request", "Box dimensions must be positive finite numbers");
  const kernel = await source;
  if (signal.aborted) throw new FacadeHandlerError("cancelled", "request was cancelled");
  let value: TechDrawResult & { ok?: boolean; error?: string; code?: string };
  try {
    value = JSON.parse(String(kernel.ccall("fc_web_dispatch_json", "string", ["string"], [JSON.stringify({ cmd: TECHDRAW_COMMAND, args: p })])));
  } catch {
    throw new FacadeHandlerError("native_protocol_error", "TechDraw native dispatcher returned invalid JSON");
  }
  if (!value || typeof value !== "object") throw new FacadeHandlerError("native_protocol_error", "TechDraw native response must be an object");
  if (value.ok !== true) throw new FacadeHandlerError(value.code ?? "native_error", value.error ?? "TechDraw drawing failed");
  if (value.schema !== TECHDRAW_SCHEMA || value.module !== "TechDraw" || value.source !== "freecad-source"
    || value.renderer !== "TechDraw.viewPartAsSvg" || value.nativeSource !== "TechDraw::DrawViewPart"
    || value.action !== "create/recompute" || !Number.isFinite(value.volume) || value.volume <= 0
    || !value.box || ![value.box.length, value.box.width, value.box.height].every(n => Number.isFinite(n) && n > 0)
    || (p.box && (value.box.length !== p.box.length || value.box.width !== p.box.width || value.box.height !== p.box.height))
    || value.document?.name !== (p.documentId ?? "TechDrawDrawing") || value.document.keptOpen !== true
    || !Number.isInteger(value.document.objectCount) || value.document.objectCount < 4
    || value.page !== "Page" || value.view !== "View"
    || !Array.isArray(value.pageSize) || value.pageSize.length !== 2 || !value.pageSize.every(n => Number.isFinite(n) && n > 0)
    || typeof value.svg !== "string" || !value.svg.includes("<path")
    || !Array.isArray(value.bounds) || value.bounds.length !== 4 || !value.bounds.every(Number.isFinite)
    || value.bounds[2] <= value.bounds[0] || value.bounds[3] <= value.bounds[1]
    || !Number.isInteger(value.edgeCount) || value.edgeCount < 1)
    throw new FacadeHandlerError("native_protocol_error", "TechDraw native response does not match the requested drawing");
  return value;
}
export function dispatchTechDraw(queue: FacadeSerialQueue, request: TechDrawRequest, source: TechDrawKernel | Promise<TechDrawKernel>): Promise<TechDrawResponse> {
  return queue.dispatch(request, (payload, signal) => handleTechDraw(payload, signal, source));
}