local M = {}
local config = require('chatgpt_nvim.config')
local conf = config.load()
local prompts = require('chatgpt_nvim.prompts')

local debug_bufnr = nil
if conf.improved_debug then
  -- Check if a debug buffer is already open. Close it first to avoid duplicates.
  for _, buf in ipairs(vim.api.nvim_list_bufs()) do
    local name = vim.api.nvim_buf_get_name(buf)
    if name == "ChatGPT_Debug_Log" then
      vim.api.nvim_buf_delete(buf, {force = true})
    end
  end

  debug_bufnr = vim.api.nvim_create_buf(false, true)
  vim.api.nvim_buf_set_name(debug_bufnr, "ChatGPT_Debug_Log")
  vim.api.nvim_buf_set_option(debug_bufnr, "filetype", "log")
end

function M.debug_log(msg)
  if conf.improved_debug and debug_bufnr then
    vim.api.nvim_buf_set_lines(debug_bufnr, -1, -1, false, { msg })
  else
    if conf.debug then
      vim.api.nvim_out_write("[chatgpt_nvim:debug] " .. msg .. "\n")
    end
  end
end

function M.pick_directories(dirs)
  local selected_dirs = {}
  local selection_instructions = prompts["file-selection-instructions"]
  local lines = { selection_instructions }

  for _, d in ipairs(dirs) do
    table.insert(lines, d)
  end

  -- If a file selection buffer is already open, close it to avoid confusion
  for _, buf in ipairs(vim.api.nvim_list_bufs()) do
    local name = vim.api.nvim_buf_get_name(buf)
    if name:match("ChatGPT_File_Selection") then
      vim.api.nvim_buf_delete(buf, {force = true})
    end
  end

  local bufnr = vim.api.nvim_create_buf(false, false)
  vim.api.nvim_buf_set_name(bufnr, "ChatGPT_File_Selection")
  vim.api.nvim_buf_set_option(bufnr, "filetype", "markdown")
  vim.api.nvim_buf_set_option(bufnr, "bufhidden", "wipe")
  vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, lines)

  local function on_write()
    local new_lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
    local final_dirs = {}
    for _, l in ipairs(new_lines) do
      if l ~= "" and not l:match("^Delete lines") and not l:match("^#") then
        table.insert(final_dirs, l)
      end
    end
    selected_dirs = final_dirs
    vim.api.nvim_buf_set_option(bufnr, "modified", false)
  end

  vim.api.nvim_create_autocmd("BufWriteCmd", {
    buffer = bufnr,
    once = true,
    callback = function()
      on_write()
      -- Automatically close the buffer once saved
      vim.cmd("bd! " .. bufnr)
    end
  })

  vim.cmd("split")
  vim.cmd("buffer " .. bufnr)

  -- Wait up to 30s for user to close
  vim.wait(30000, function()
    local winids = vim.api.nvim_tabpage_list_wins(0)
    for _, w in ipairs(winids) do
      local b = vim.api.nvim_win_get_buf(w)
      if b == bufnr then
        return false
      end
    end
    return true
  end)

  return selected_dirs
end

return M