neovim print to pdf using markdown

markdown_to_pdf.lua

-- markdown_to_pdf.lua
-- Generates a PDF from a Markdown file in two steps:
--   1. Markdown -> HTML with pandoc (with embedded CSS)
--   2. HTML -> PDF with Google Chrome in headless mode
-- The intermediate HTML file is deleted at the end, leaving only the PDF.
--
-- Usage:  :MarkdownToPDF            (converts the current buffer)
--         :MarkdownToPDF path.md    (converts the given file)
--
-- Requires Neovim 0.10+ (uses vim.system).
--
-- Register the command in your init.lua:
--   require("markdown_to_pdf").setup()

local M = {}

-- Path to the Chrome binary on macOS.
local CHROME = "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"

-- Stylesheet to apply. Stored inside the Neovim config.
local CSS_PATH = vim.fn.expand("~/.config/nvim/assets/print.css")

--- Runs a command, reporting an error via vim.notify on failure.
--- @param cmd table     Command + arguments for vim.system.
--- @param label string  Name shown in the error message.
--- @return boolean ok   true if the command exited with code 0.
local function run(cmd, label)
  local result = vim.system(cmd):wait()
  if result.code ~= 0 then
    vim.notify(label .. " failed: " .. (result.stderr or ""), vim.log.levels.ERROR)
    return false
  end
  return true
end

--- Converts Markdown to a self-contained HTML file with embedded CSS.
--- @param md_path string    Path to the input Markdown file.
--- @param html_path string  Path where the HTML will be generated.
--- @return boolean ok
local function markdown_to_html(md_path, html_path)
  -- -s                 standalone document with <head>.
  -- --embed-resources  inlines the CSS as a <style> block, so the HTML is
  --                    self-contained and is the only file left to delete.
  return run({
    "pandoc",
    md_path,
    "-s",
    "--embed-resources",
    "--css=" .. CSS_PATH,
    "-o",
    html_path,
  }, "pandoc")
end

--- Converts a local HTML file to PDF with headless Chrome.
--- @param html_path string  Path to the input HTML.
--- @param pdf_path string   Path where the PDF will be generated.
--- @return boolean ok
local function html_to_pdf(html_path, pdf_path)
  -- file://                 prints from disk, no server needed.
  -- --no-pdf-header-footer  drops the date/URL Chrome adds to each page.
  return run({
    CHROME,
    "--headless",
    "--disable-gpu",
    "--no-pdf-header-footer",
    "--print-to-pdf=" .. pdf_path,
    "file://" .. html_path,
  }, "Chrome")
end

--- Orchestrates the full conversion Markdown -> HTML -> PDF.
--- @param md_path string  Absolute path to the input Markdown file.
local function convert(md_path)
  if vim.fn.filereadable(md_path) == 0 then
    vim.notify("File does not exist: " .. md_path, vim.log.levels.ERROR)
    return
  end

  -- Output files are written next to the Markdown source.
  local dir = vim.fn.fnamemodify(md_path, ":p:h")
  local stem = vim.fn.fnamemodify(md_path, ":t:r") -- filename without extension
  local html_path = dir .. "/" .. stem .. ".html"
  local pdf_path = dir .. "/" .. stem .. ".pdf"

  vim.notify("converting markdown to html...", vim.log.levels.INFO)
  if not markdown_to_html(md_path, html_path) then
    return
  end

  vim.notify("converting html to pdf...", vim.log.levels.INFO)
  if not html_to_pdf(html_path, pdf_path) then
    return
  end

  -- The HTML was only an intermediate step; the CSS is baked into the PDF.
  vim.fn.delete(html_path)

  vim.notify("PDF generated: " .. pdf_path, vim.log.levels.INFO)
  vim.fn.system("open " .. pdf_path)
end

--- Registers the :MarkdownToPDF command. Call from your init.lua:
---   require("markdown_to_pdf").setup()
function M.setup()
  vim.api.nvim_create_user_command("MarkdownToPDF", function(opts)
    -- Use the given file if any, otherwise the current buffer.
    local md_path = opts.args ~= "" and opts.args or vim.api.nvim_buf_get_name(0)
    convert(vim.fn.fnamemodify(md_path, ":p"))
  end, {
    nargs = "?", -- optional argument (file path)
    complete = "file", -- file path autocompletion with <Tab>
    desc = "Generates a PDF from Markdown (pandoc + headless Chrome)",
  })
end

return M

print.css

/*
 * github like style mejorado para print
 * https://github.com/iamcco/markdown.css/blob/master/dest/github/markdown.css
 */

:root {
  --color-text-primary: #000000;
  --color-text-secondary: #075b9e;
  --color-text-tertiary: #777;
  --color-text-link: #4078c0;
  --color-bg-primary: #fff;
  --color-bg-secondary: #fafbfc;
  --color-bg-tertiary: #f8f8f8;
  --color-border-primary: #dddddd;
  --color-border-secondary: #eaecef;
  --color-border-tertiary: #d1d5da;
  --color-kbd-foreground: #444d56;
  --color-markdown-blockquote-border: #dfe2e5;
  --color-markdown-table-border: #dfe2e5;
  --color-markdown-table-tr-border: #c6cbd1;
  --color-markdown-code-bg: #1b1f230d;
}
/* 1. Aseguramos que el contenedor raíz no tenga márgenes y ocupe el alto */
html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
}
/*css for screen*/
html {
  font-size: 11px;
}
body ol ol,
body ul ol,
body ol ul,
body ul ul,
body ol ul ol,
body ul ul ol,
body ol ul ul,
body ul ul ul {
  margin-top: 0;
  margin-bottom: 0;
}
body {
  font-family: "Helvetica Neue", Helvetica, "Segoe UI", Arial, freesans, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  color: var(--color-text-primary);
  line-height: 1.6;
  word-wrap: break-word;
  padding: 45px;
  background: var(--color-bg-primary);
  /* --- CAMBIOS PARA ALTURA COMPLETA --- */
  min-height: 100vh; /* Ocupa el 100% del Viewport Height */
  display: flex; /* Opcional: útil si quieres centrar contenido verticalmente */
  flex-direction: column;
  box-sizing: border-box; /* Asegura que el padding no sume extra al 100vh */
}
body > *:first-child {
  margin-top: 0 !important;
}
body > *:last-child {
  margin-bottom: 0 !important;
}
body .table-of-contents ol {
  list-style: none;
}
body .table-of-contents > ol {
  padding-left: 0;
}
body * {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
body h1,
body h2,
body h3,
body h4,
body h5,
body h6 {
  margin-top: 1em;
  margin-bottom: 16px;
  font-weight: bold;
  line-height: 1.4;
}

body h1 {
  border-bottom: 1px solid var(--color-border-secondary);
  margin-bottom: 18px;
}

body h1 .anchor,
body h2 .anchor,
body h3 .anchor,
body h4 .anchor,
body h5 .anchor,
body h6 .anchor {
  margin-left: -24px;
  visibility: hidden;
}
body h1:hover .anchor,
body h2:hover .anchor,
body h3:hover .anchor,
body h4:hover .anchor,
body h5:hover .anchor,
body h6:hover .anchor {
  visibility: visible;
}
body p,
body blockquote,
body ul,
body ol,
body dl,
body table,
body pre {
  margin-top: 0;
  margin-bottom: 16px;
}
body h1 {
  margin: 0.67em 0;
  padding-bottom: 0.3em;
  font-size: 1.6em;
  line-height: 1.2;
  color: var(--color-text-primary);
  /* border-bottom: 1px solid var(--color-border-secondary); */
}
body h2 {
  padding-bottom: 0.3em;
  font-size: 1.2em;
  line-height: 1.225;
  color: var(--color-text-primary);
  /* border-bottom: 1px solid var(--color-border-secondary); */
}
body h3 {
  font-size: 1em;
  line-height: 1.43;
  color: var(--color-text-secondary);
}
body h4 {
  font-size: 0.8em;
  color: var(--color-text-tertiary);
}
body h5 {
  font-size: 0.6em;
}
body h6 {
  font-size: 0.5em;
}
body hr {
  margin-top: 20px;
  margin-bottom: 20px;
  height: 0;
  border: 0;
  border-top: 1px solid var(--color-border-primary, #ddd);
}
body ol,
body ul {
  padding-left: 2em;
}
body ol ol,
body ul ol {
  list-style-type: lower-roman;
}
body ol ul,
body ul ul {
  list-style-type: circle;
}
body ol ul ul,
body ul ul ul {
  list-style-type: square;
}
body ol {
  list-style-type: decimal;
}
body ul {
  list-style-type: disc;
}
body dl {
  margin-bottom: 1.3em;
}
body dl dt {
  font-weight: 700;
}
body dl dd {
  margin-left: 0;
}
body dl dd p {
  margin-bottom: 0.8em;
}
body blockquote {
  margin-left: 0;
  margin-right: 0;
  padding: 0 15px;
  color: var(--color-text-tertiary);
  border-left: 4px solid var(--color-markdown-blockquote-border);
}
body table {
  display: block;
  width: 100%;
  word-break: normal;
  word-break: keep-all;
  border-collapse: collapse;
  border-spacing: 0;
}
body table tr {
  background-color: var(--color-bg-primary);
  border-top: 1px solid var(--color-markdown-table-tr-border);
}
body table tr:nth-child(2n) {
  background-color: var(--color-bg-tertiary);
}
body table th,
body table td {
  padding: 6px 13px;
  border: 1px solid var(--color-markdown-table-border);
  vertical-align: top;
}
body kbd {
  display: inline-block;
  padding: 5px 6px;
  font:
    14px SFMono-Regular,
    Consolas,
    Liberation Mono,
    Menlo,
    monospace;
  line-height: 10px;
  color: var(--color-kbd-foreground);
  vertical-align: middle;
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border-tertiary);
  border-radius: 3px;
  box-shadow: inset 0 -1px 0 var(--color-border-tertiary);
}
body pre {
  word-wrap: normal;
  padding: 16px;
  font-size: 85%;
  line-height: 1.45;
  background-color: var(--color-bg-tertiary);
  -webkit-border-radius: 3px;
  border-radius: 3px;
}
body pre code {
  display: inline;
  max-width: initial;
  padding: 0;
  margin: 0;
  font-size: 100%;
  line-height: inherit;
  word-wrap: normal;
  white-space: pre;
  border: 0;
  -webkit-border-radius: 3px;
  border-radius: 3px;
  background-color: transparent;
}
body pre code:before,
body pre code:after {
  content: normal;
}
body code {
  font-family: Consolas, "Liberation Mono", Menlo, Courier, monospace;
  padding: 0;
  padding-top: 0.2em;
  padding-bottom: 0.2em;
  margin: 0;
  font-size: 85%;
  background-color: var(--color-markdown-code-bg);
  -webkit-border-radius: 3px;
  border-radius: 3px;
}
body code:before,
body code:after {
  letter-spacing: -0.2em;
  content: "\00a0";
}
body a {
  color: var(--color-text-link);
  text-decoration: none;
  background: transparent;
}
body img {
  max-width: 100%;
  max-height: 100%;
}
body figure {
  margin: 0;
}
body strong {
  font-weight: bold;
}
body em {
  font-style: italic;
}
body del {
  text-decoration: line-through;
}
.task-list-item {
  list-style-type: none;
}
.task-list-item input {
  font:
    13px/1.4 Helvetica,
    arial,
    nimbussansl,
    liberationsans,
    freesans,
    clean,
    sans-serif,
    "Apple Color Emoji",
    "Segoe UI Emoji",
    "Segoe UI Symbol";
  margin: 0 0.35em 0.25em -1.6em;
  vertical-align: middle;
}
.task-list-item input[disabled] {
  cursor: default;
}
.task-list-item input[type="checkbox"] {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  padding: 0;
}
.task-list-item input[type="radio"] {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  padding: 0;
}
body h1,
body h2,
body h3,
body h4,
body h4 {
  clear: both;
}
#page-header {
  display: none;
}
/* force page break on print */
.break {
  page-break-before: always;
}