-- Minimal fuzzy finder + content search in pure Neovim Lua
-- Requires: optional `fdfind` or `fd`, optional `rg` (ripgrep)

local Fuzzy = {}

--------------------------------------------------------------------
-- 🧩 Helper: collect file list (fd > globpath)
--------------------------------------------------------------------
local function get_file_list()
  local handle = io.popen('fdfind --type f 2>/dev/null || fd --type f 2>/dev/null')
  if handle then
    local result = handle:read('*a')
    handle:close()
    if result ~= '' then
      return vim.split(result, '\n', { trimempty = true })
    end
  end
  return vim.fn.globpath('.', '**/*', 0, 1)
end

--------------------------------------------------------------------
-- 🧩 Helper: open a floating pair of windows (input + results)
--------------------------------------------------------------------
local function open_float(prompt)
  local input_buf = vim.api.nvim_create_buf(false, true)
  local result_buf = vim.api.nvim_create_buf(false, true)

  local width = math.floor(vim.o.columns * 0.7)
  local height = 20
  local row = math.floor((vim.o.lines - height) / 2)
  local col = math.floor((vim.o.columns - width) / 2)

  local input_win = vim.api.nvim_open_win(input_buf, true, {
    relative = 'editor',
    row = row,
    col = col,
    width = width,
    height = 1,
    style = 'minimal',
    border = 'rounded',
  })
  vim.api.nvim_buf_set_option(input_buf, 'buftype', 'prompt')
  vim.fn.prompt_setprompt(input_buf, prompt)

  local result_win = vim.api.nvim_open_win(result_buf, false, {
    relative = 'editor',
    row = row + 2,
    col = col,
    width = width,
    height = height - 2,
    style = 'minimal',
    border = 'single',
  })

  return input_buf, result_buf, input_win, result_win
end

--------------------------------------------------------------------
-- 🔵 Highlight selection
--------------------------------------------------------------------
function Fuzzy:highlight_selection()
  if not self.result_buf then
    return
  end
  vim.api.nvim_buf_clear_namespace(self.result_buf, 0, 0, -1)
  if self.matches and self.matches[self.cursor] then
    vim.api.nvim_buf_add_highlight(self.result_buf, 0, 'Visual', self.cursor - 1, 0, -1)
  end
end

--------------------------------------------------------------------
-- 🔴 Close all floating windows
--------------------------------------------------------------------
function Fuzzy.close()
  if Fuzzy.input_win and vim.api.nvim_win_is_valid(Fuzzy.input_win) then
    vim.api.nvim_win_close(Fuzzy.input_win, true)
  end
  if Fuzzy.result_win and vim.api.nvim_win_is_valid(Fuzzy.result_win) then
    vim.api.nvim_win_close(Fuzzy.result_win, true)
  end
  Fuzzy.active = false
end

--------------------------------------------------------------------
-- 🟢 File finder (fdfind + fuzzy match)
--------------------------------------------------------------------
function Fuzzy.open()
  if Fuzzy.active then
    Fuzzy.close()
  end
  Fuzzy.active = true

  Fuzzy.files = get_file_list()
  Fuzzy.matches = Fuzzy.files
  Fuzzy.cursor = 1

  Fuzzy.input_buf, Fuzzy.result_buf, Fuzzy.input_win, Fuzzy.result_win = open_float('Search: ')

  local function update_results(text)
    if text == '' then
      Fuzzy.matches = Fuzzy.files
    else
      Fuzzy.matches = vim.fn.matchfuzzy(Fuzzy.files, text)
    end
    if #Fuzzy.matches == 0 then
      vim.api.nvim_buf_set_lines(Fuzzy.result_buf, 0, -1, false, { '-- no matches --' })
      Fuzzy.cursor = 1
      return
    end
    local display = {}
    for i = 1, math.min(#Fuzzy.matches, 50) do
      table.insert(display, Fuzzy.matches[i])
    end
    vim.api.nvim_buf_set_lines(Fuzzy.result_buf, 0, -1, false, display)
    Fuzzy.cursor = 1
    Fuzzy:highlight_selection()
  end

  -- Live updates
  vim.api.nvim_create_autocmd({ 'TextChangedI', 'TextChangedP' }, {
    buffer = Fuzzy.input_buf,
    callback = function()
      local text = vim.fn.getline('.')
      text = text:gsub('^Search:%s*', '')
      update_results(text)
    end,
  })

  -- Keymaps
  vim.keymap.set('i', '<C-n>', function()
    Fuzzy.cursor = math.min(Fuzzy.cursor + 1, #Fuzzy.matches)
    Fuzzy:highlight_selection()
  end, { buffer = Fuzzy.input_buf })

  vim.keymap.set('i', '<C-p>', function()
    Fuzzy.cursor = math.max(Fuzzy.cursor - 1, 1)
    Fuzzy:highlight_selection()
  end, { buffer = Fuzzy.input_buf })

  vim.keymap.set('i', '<CR>', function()
    local choice = Fuzzy.matches[Fuzzy.cursor]
    if choice then
      Fuzzy.close()
      vim.cmd('edit ' .. vim.fn.fnameescape(choice))
    end
  end, { buffer = Fuzzy.input_buf })

  vim.keymap.set('i', '<Esc>', function()
    Fuzzy.close()
  end, { buffer = Fuzzy.input_buf })

  vim.cmd('startinsert')
end

--------------------------------------------------------------------
-- 🟣 Ripgrep-powered content search
--------------------------------------------------------------------
function Fuzzy.open_grep()
  if Fuzzy.active then
    Fuzzy.close()
  end
  Fuzzy.active = true

  Fuzzy.input_buf, Fuzzy.result_buf, Fuzzy.input_win, Fuzzy.result_win = open_float('Grep: ')
  Fuzzy.matches = {}
  Fuzzy.cursor = 1

  local function run_grep(query)
    if query == '' then
      vim.api.nvim_buf_set_lines(Fuzzy.result_buf, 0, -1, false, { '-- type to search --' })
      return
    end
    local handle = io.popen('rg --vimgrep --hidden --smart-case ' .. vim.fn.shellescape(query))
    if not handle then
      return
    end
    local result = handle:read('*a')
    handle:close()
    Fuzzy.matches = vim.split(result, '\n', { trimempty = true })
    if #Fuzzy.matches == 0 then
      vim.api.nvim_buf_set_lines(Fuzzy.result_buf, 0, -1, false, { '-- no matches --' })
      return
    end
    local display = {}
    for i = 1, math.min(#Fuzzy.matches, 50) do
      table.insert(display, Fuzzy.matches[i])
    end
    vim.api.nvim_buf_set_lines(Fuzzy.result_buf, 0, -1, false, display)
    Fuzzy.cursor = 1
    Fuzzy:highlight_selection()
  end

  vim.api.nvim_create_autocmd({ 'TextChangedI', 'TextChangedP' }, {
    buffer = Fuzzy.input_buf,
    callback = function()
      local text = vim.fn.getline('.')
      text = text:gsub('^Grep:%s*', '')
      run_grep(text)
    end,
  })

  -- Navigation
  vim.keymap.set('i', '<C-n>', function()
    Fuzzy.cursor = math.min(Fuzzy.cursor + 1, #Fuzzy.matches)
    Fuzzy:highlight_selection()
  end, { buffer = Fuzzy.input_buf })

  vim.keymap.set('i', '<C-p>', function()
    Fuzzy.cursor = math.max(Fuzzy.cursor - 1, 1)
    Fuzzy:highlight_selection()
  end, { buffer = Fuzzy.input_buf })

  vim.keymap.set('i', '<CR>', function()
    local line = Fuzzy.matches[Fuzzy.cursor]
    if line then
      local parts = vim.split(line, ':')
      local file = parts[1]
      local lnum = tonumber(parts[2]) or 1
      Fuzzy.close()
      vim.cmd('edit ' .. vim.fn.fnameescape(file))
      vim.api.nvim_win_set_cursor(0, { lnum, 0 })
    end
  end, { buffer = Fuzzy.input_buf })

  vim.keymap.set('i', '<Esc>', function()
    Fuzzy.close()
  end, { buffer = Fuzzy.input_buf })

  vim.cmd('startinsert')
end

--------------------------------------------------------------------
-- 🧩 Commands & Keymaps
--------------------------------------------------------------------
vim.api.nvim_create_user_command('FuzzyLive', function()
  Fuzzy.open()
end, {})
vim.api.nvim_create_user_command('FuzzyGrep', function()
  Fuzzy.open_grep()
end, {})

vim.keymap.set('n', '<leader>f', function()
  vim.cmd('FuzzyLive')
end, { desc = 'Open fuzzy file finder' })
vim.keymap.set('n', '<leader>g', function()
  vim.cmd('FuzzyGrep')
end, { desc = 'Search file contents with ripgrep' })

return Fuzzy