local keymap = vim.keymap

-- FZF lua headings picker
local picker = require("fzf-lua")

local function fzf_lua_markdown_headings()
  local bufnr = vim.api.nvim_get_current_buf()
  local headings = {}

  -- Check if treesitter parser is available
  local ok, parser = pcall(vim.treesitter.get_parser, bufnr, 'markdown')
  if not ok or not parser then
    vim.notify("Treesitter markdown parser not available", vim.log.levels.ERROR)
    return
  end

  local query = vim.treesitter.query.parse('markdown', [[
    (atx_heading
      (atx_h1_marker)) @heading
  ]])

  local tree = parser:parse()[1]
  local root = tree:root()

  for id, node in query:iter_captures(root, bufnr, 0, -1) do
    local start_row, start_col, end_row, end_col = node:range()
    local lnum = start_row + 1 -- Treesitter is 0-indexed, Vim is 1-indexed
    local text = vim.treesitter.get_node_text(node, bufnr)

    table.insert(headings, {
      lnum = lnum,
      text = text,
      display = string.format("%4d: %s", lnum, text)
    })
  end

  picker.fzf_exec(function(fzf_cb)
    for _, heading in ipairs(headings) do
      fzf_cb(heading.display)
    end
    fzf_cb() -- EOF
  end, {
    prompt = "Markdown headings> ",
    actions = {
      ['default'] = function(selected)
        local line_num = tonumber(selected[1]:match("%d+"))
        vim.api.nvim_win_set_cursor(0, { line_num, 0 })
      end
    }
  })
end

keymap.set("n", "<leader>fdh", fzf_lua_markdown_headings, { desc = "Grep: Markdown headings" })