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/*
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This is a very lightweight ipynb parser in pure javascript.
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It's used, e.g., in our analogue of nbviewer.
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*/
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import { IPynbImporter } from "@cocalc/jupyter/ipynb/import-from-ipynb";
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import { JUPYTER_MIMETYPES } from "@cocalc/jupyter/util/misc";
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import { field_cmp } from "@cocalc/util/misc";
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export interface KernelSpec {
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  language?: string;
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  display_name: string;
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  name: string;
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}
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export interface CoCalcJupyter {
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  cellList: string[];
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  cells: { [id: string]: object };
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  cmOptions?: { [field: string]: any };
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  metadata?;
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  kernelspec: KernelSpec;
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}
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export default function parse(content: string): CoCalcJupyter {
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  const ipynb = JSON.parse(content);
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  const importer = new IPynbImporter();
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  importer.import({
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    ipynb,
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    output_handler: (cell) => {
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      let k: number = 0;
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      return {
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        message: (content) => {
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          process(content);
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          cell.output[`${k}`] = content;
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          k += 1;
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        },
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      };
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    },
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  });
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  const cells = importer.cells();
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  const cellList = sortedCellList(cells);
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  const cmOptions = getCMOptions(getMode(ipynb));
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  const kernelspec = ipynb.metadata?.kernelspec ?? {
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    display_name: "Unknown Kernel",
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  };
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  return { cells, cellList, cmOptions, kernelspec };
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}
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export function getMode(ipynb): string {
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  return (
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    ipynb.metadata?.language_info?.codemirror_mode ??
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    ipynb.metadata?.language_info?.name ??
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    ipynb.metadata?.kernelspec?.language?.toLowerCase() ??
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    "python"
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  );
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}
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export function getCMOptions(
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  mode: string | { name: string } | undefined | null,
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) {
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  if (mode == null) {
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    mode = { name: "python" };
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  }
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  if (typeof mode === "string") {
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    mode = { name: mode };
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  }
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  if (mode.name.includes("python") || mode.name.includes("sage")) {
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    mode.name = "python";
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  } else if (mode.name === "gp") {
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    mode.name = "pari";
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  } else if (mode.name === "singular") {
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    mode.name = "clike"; // better than nothing
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  } else if (mode.name === "ihaskell") {
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    mode.name = "haskell";
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  }
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  return {
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    mode,
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    showTrailingSpace: true,
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    tabSize: 4,
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    lineWrapping: true,
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    readOnly: true,
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  };
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}
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function process(content): void {
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  if (content?.data == null) {
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    return;
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  }
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  for (const type of JUPYTER_MIMETYPES) {
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    if (
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      content.data[type] != null &&
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      (type.split("/")[0] === "image" || type === "application/pdf")
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    ) {
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      content.data[type] = { value: content.data[type] };
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    }
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  }
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}
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function sortedCellList(cells): string[] {
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  // Given map from id's to cells, returns an list of ids in correct order,
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  // as defined by pos field.
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  const v: { id: string; pos: number }[] = [];
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  for (const id in cells) {
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    v.push({ id, pos: cells[id]?.pos ?? -1 });
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  }
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  v.sort(field_cmp("pos"));
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  const a: string[] = [];
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  for (const { id } of v) {
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    a.push(id);
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  }
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  return a;
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}
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