import { prepareOdfPackage, type PreparedOdfPackage } from "./package";
import { parseFrameImage, parseTextBlocks, parseTextTable } from "./text";
import type {
  OdfParseOptions,
  OdfPresentationDocument,
  OdfPresentationShape,
  OdfPresentationShapeType,
  OdfPresentationSlide,
} from "./types";
import { OdfParseError } from "./types";
import {
  NS,
  attribute,
  childElements,
  childrenNamed,
  firstChildNamed,
  parseLength,
  type XmlElement,
} from "./xml";

export function parseOdp(
  input: ArrayBuffer,
  options: Omit<OdfParseOptions, "expectedFormat"> = {},
): OdfPresentationDocument {
  const prepared = prepareOdfPackage(input, {
    ...options,
    expectedFormat: "odp",
  });
  return parsePreparedOdp(prepared);
}

export function parsePreparedOdp(
  prepared: PreparedOdfPackage,
): OdfPresentationDocument {
  if (prepared.format !== "odp") {
    throw new OdfParseError(
      "type-mismatch",
      "Prepared package is not an ODP document",
    );
  }
  const body = firstChildNamed(
    prepared.content.documentElement!,
    NS.office,
    "body",
  );
  const presentation = body && firstChildNamed(body, NS.office, "presentation");
  if (!presentation) {
    throw new OdfParseError(
      "type-mismatch",
      "ODP content.xml does not contain an office:presentation document body",
    );
  }
  const slides = childrenNamed(presentation, NS.draw, "page").map(
    (page, index) => parseSlide(page, index, prepared.context),
  );
  return {
    format: "odp",
    mediaType: prepared.mediaType,
    metadata: prepared.metadata,
    styles: prepared.styles,
    assets: prepared.context.assets,
    warnings: prepared.context.warnings,
    pageWidth: prepared.pageWidth,
    pageHeight: prepared.pageHeight,
    slides,
  };
}

function parseSlide(
  page: XmlElement,
  index: number,
  context: ReturnType<typeof prepareOdfPackage>["context"],
): OdfPresentationSlide {
  const notesElement = firstChildNamed(page, NS.presentation, "notes");
  const shapes: OdfPresentationShape[] = [];
  let shapeIndex = 0;
  for (const element of childElements(page)) {
    if (element === notesElement || element.namespaceURI !== NS.draw) continue;
    shapes.push(
      parseShape(element, `slide-${index + 1}-shape-${++shapeIndex}`, context),
    );
  }
  return {
    name: attribute(page, NS.draw, "name") ?? `Slide ${index + 1}`,
    styleName: attribute(page, NS.draw, "style-name"),
    masterPageName: attribute(page, NS.draw, "master-page-name"),
    layoutName: attribute(
      page,
      NS.presentation,
      "presentation-page-layout-name",
    ),
    shapes,
    notes: notesElement ? parseTextBlocks(notesElement, context) : [],
  };
}

function parseShape(
  element: XmlElement,
  fallbackId: string,
  context: ReturnType<typeof prepareOdfPackage>["context"],
): OdfPresentationShape {
  const image =
    element.localName === "frame"
      ? parseFrameImage(element, context)
      : undefined;
  const textBox = firstChildNamed(element, NS.draw, "text-box");
  const tableElement =
    firstChildNamed(element, NS.table, "table") ??
    (textBox ? firstChildNamed(textBox, NS.table, "table") : undefined);
  const table = tableElement
    ? parseTextTable(tableElement, context)
    : undefined;
  const children: OdfPresentationShape[] = [];
  if (element.localName === "g") {
    let index = 0;
    for (const child of childElements(element)) {
      if (child.namespaceURI === NS.draw) {
        children.push(parseShape(child, `${fallbackId}-${++index}`, context));
      }
    }
  }
  const blocks = textBox
    ? parseTextBlocks(textBox, context).filter(
        (block) => block.kind !== "table",
      )
    : parseTextBlocks(element, context);
  return {
    id: attribute(element, NS.draw, "id") ?? fallbackId,
    type: shapeType(
      element,
      image !== undefined,
      table !== undefined,
      textBox !== undefined,
    ),
    name: attribute(element, NS.draw, "name"),
    styleName: attribute(element, NS.draw, "style-name"),
    textStyleName: attribute(element, NS.draw, "text-style-name"),
    layer: attribute(element, NS.draw, "layer"),
    x: parseLength(attribute(element, NS.svg, "x")),
    y: parseLength(attribute(element, NS.svg, "y")),
    width: parseLength(attribute(element, NS.svg, "width")),
    height: parseLength(attribute(element, NS.svg, "height")),
    transform: attribute(element, NS.draw, "transform"),
    blocks,
    image,
    table,
    children,
  };
}

function shapeType(
  element: XmlElement,
  hasImage: boolean,
  hasTable: boolean,
  hasTextBox: boolean,
): OdfPresentationShapeType {
  if (hasImage) return "image";
  if (hasTable) return "table";
  if (hasTextBox) return "text-box";
  if (element.localName === "rect") return "rectangle";
  if (element.localName === "ellipse" || element.localName === "circle")
    return "ellipse";
  if (element.localName === "line") return "line";
  if (element.localName === "custom-shape") return "custom";
  if (element.localName === "g") return "group";
  return "unknown";
}