- [ ] automata library module

- [x] automata library module

    - [ ] a0 <> a1 like for map generation (find that interesting one)

    - [ ] a0 <> a1 like for map generation (find that interesting one: glider -> terra slaps)

-- vim.keymap.set('n', '<leader>e', vim.diagnostic.open_float, opts)
-- vim.keymap.set('n', '<leader>h', vim.diagnostic.hide, opts)
vim.keymap.set('n', '[d', vim.diagnostic.goto_prev, opts)
vim.keymap.set('n', ']d', vim.diagnostic.goto_next, opts)
vim.keymap.set('n', '<leader>q', vim.diagnostic.setloclist, opts)

   -- -- PATCH: override all diagnostic highlights to be severity based
   -- -- to mitigate severity being ignored in the special cases of DiagnosticDeprecated and DiagnosticUnnecessary
   -- --
   -- -- foollow relevant issues:
   -- -- #26796 (nvim) https://github.com/neovim/neovim/issues/26796#issuecomment-3236801970
   -- -- #1677 (kickstart.nvim)
   -- -- #1550 (kickstart.nvim)
   -- --
      -- Create namespace for our custom highlights
      local ns_id = vim.api.nvim_create_namespace('diagnostic_text_highlight')
      -- Function to apply highlights to diagnostic ranges
      local function highlight_diagnostic_text()
        -- Clear previous highlights
        vim.api.nvim_buf_clear_namespace(0, ns_id, 0, -1)
        -- Get diagnostics for current buffer
        local diagnostics = vim.diagnostic.get(0)
        for _, diagnostic in ipairs(diagnostics) do
          local severity = diagnostic.severity
          local start_line = diagnostic.lnum
          local start_col = diagnostic.col
          local end_line = diagnostic.end_lnum or start_line
          local end_col = diagnostic.end_col or (start_col + 1)
          -- Choose highlight group based on severity
          local hl_group
          if severity == vim.diagnostic.severity.ERROR then
            hl_group = 'DiagnosticError'
          elseif severity == vim.diagnostic.severity.WARN then
            hl_group = 'DiagnosticWarn'
          elseif severity == vim.diagnostic.severity.INFO then
            hl_group = 'DiagnosticInfo'
          elseif severity == vim.diagnostic.severity.HINT then
            hl_group = 'DiagnosticHint'
          end
          -- Apply highlight to the specific range
          if hl_group then
            vim.highlight.range(
              0,                    -- buffer (0 = current)
              ns_id,               -- namespace
              hl_group,            -- highlight group
              { start_line, start_col }, -- start position
              { end_line, end_col }      -- end position
            )
          end
        end

-- PATCH:
-- The built-in underline handler applies tag highlights (DiagnosticUnnecessary,
-- DiagnosticDeprecated) at the same priority as severity highlights, with tags
-- winning by application order. We pass copies with _tags stripped so only the
-- severity highlight is applied.
-- Upstream: https://github.com/neovim/neovim/issues/26796
local orig_underline = vim.diagnostic.handlers.underline
vim.diagnostic.handlers.underline = {
  show = function(namespace, bufnr, diagnostics, opts)
    local stripped = {}
    for _, d in ipairs(diagnostics) do
      if d._tags then
        local copy = vim.tbl_extend('keep', {}, d)
        copy._tags = nil
        stripped[#stripped + 1] = copy
      else
        stripped[#stripped + 1] = d

      -- Create autocmd for DiagnosticChanged event
      vim.api.nvim_create_autocmd('DiagnosticChanged', {
        callback = highlight_diagnostic_text,
        desc = 'Highlight diagnostic text with custom colors'
      })
      -- Also apply highlights when entering a buffer (for existing diagnostics)
      vim.api.nvim_create_autocmd('BufEnter', {
        callback = highlight_diagnostic_text,
        desc = 'Apply diagnostic text highlights on buffer enter'
      })
   -- --

    end
    orig_underline.show(namespace, bufnr, stripped, opts)
  end,
  hide = orig_underline.hide,
}