-- TODO: Customize keymap
local a = vim.api
local ns_telescope_selection = a.nvim_create_namespace('telescope_selection')

local state = require('telescope.state')

local mappings = {}
local keymap = {}
local telescope_selections = {}

mappings.set_keymap = function(prompt_bufnr, results_bufnr)
  local function default_mapper(map_key, table_key)
    a.nvim_buf_set_keymap(
      prompt_bufnr,
      'i',
      map_key,
      string.format(
        [[<C-O>:lua __TelescopeMapping(%s, %s, '%s')<CR>]],
        prompt_bufnr,
        results_bufnr,
        table_key
        ),
      {
        silent = true,
      }
    )
  end

  default_mapper('<c-n>', 'control-n')
  default_mapper('<c-p>', 'control-p')
  default_mapper('<CR>', 'enter')
end

local function update_current_selection(prompt_bufnr, results_bufnr, row)
  local status = state.get_status(prompt_bufnr)

  a.nvim_buf_clear_namespace(results_bufnr, ns_telescope_selection, 0, -1)
  a.nvim_buf_add_highlight(
    results_bufnr,
    ns_telescope_selection,
    'Error',
    row,
    0,
    -1
  )

  telescope_selections[prompt_bufnr] = row

  if status.previewer then
    vim.g.got_here = true

    status.previewer:preview(
      status.preview_win,
      status.preview_bufnr,
      status.results_bufnr,
      row
    )
  end
end


function __TelescopeMapping(prompt_bufnr, results_bufnr, characters)
  if keymap[characters] then
    keymap[characters](prompt_bufnr, results_bufnr)
  end
end

-- TODO: Refactor this to use shared code.
-- TODO: Move from top to bottom, etc.
-- TODO: It seems like doing this brings us back to the beginning of the prompt, which is not great.
keymap["control-n"] = function(prompt_bufnr, results_bufnr)
  if telescope_selections[prompt_bufnr] == nil then
    telescope_selections[prompt_bufnr] = 0
  end

  local row = telescope_selections[prompt_bufnr] + 1
  update_current_selection(prompt_bufnr, results_bufnr, row)
end

keymap["control-p"] = function(prompt_bufnr, results_bufnr)
  if telescope_selections[prompt_bufnr] == nil then
    telescope_selections[prompt_bufnr] = 0
  end

  local row = telescope_selections[prompt_bufnr] - 1
  update_current_selection(prompt_bufnr, results_bufnr, row)
end

keymap["enter"] = function(prompt_bufnr, results_bufnr)
  local extmark = a.nvim_buf_get_extmarks(
    results_bufnr,
    ns_telescope_selection,
    0,
    -1,
    {}
  )

  local row = extmark[1][2]
  if row == nil then
    print("Could not do anything...")
    return
  else
    local line = a.nvim_buf_get_lines(results_bufnr, row, row + 1, false)[1]
    if line == nil then
      print("Could not do anything with blank line...")
      return
    end

    local sections = vim.split(line, ":")

    local filename = sections[1]
    local row = tonumber(sections[2])
    local col = tonumber(sections[3])

    vim.cmd(string.format([[bdelete! %s]], prompt_bufnr))

    local bufnr = vim.fn.bufnr(filename, true)
    a.nvim_set_current_buf(bufnr)
    a.nvim_buf_set_option(bufnr, 'buflisted', true)
    a.nvim_win_set_cursor(0, {row, col})
  end
end

return mappings