dotfiles/.config/nixpkgs/neovim/config/lua/user/plugins/telescope.lua

-- file/buffer/etc picker
local telescope = require('telescope')
local telescope_actions = require('telescope.actions')
local telescope_builtin = require('telescope.builtin')
local telescope_pickers = require('telescope.pickers')
local telescope_finders = require('telescope.finders')
local telescope_themes = require('telescope.themes')
local telescope_previewers = require('telescope.previewers')
local telescope_putils = require('telescope.previewers.utils')
local telescope_conf = require('telescope.config').values
local action_state = require('telescope.actions.state')
local util = require('user.util')

local actions = {}

actions.git_show_commit = function(prompt_bufnr)
  local selection = action_state.get_selected_entry()
  local path = vim.fn.FugitiveFind(selection.value)
  telescope_actions.close(prompt_bufnr)
  vim.cmd.edit(path)
end

local commit_mappings = {
  i = {
    ['<CR>'] = actions.git_show_commit,
    ['<C-r>c'] = telescope_actions.git_checkout,
  }
}

telescope.setup({
  defaults = {
    mappings = {
      i = {
        ['<Esc>'] = 'close',
        ['<C-e>'] = 'close',
      },
    },
    layout_config = {
      prompt_position = 'top',
    },
    sorting_strategy = 'ascending',
    -- use filename as preview window title
    dynamic_preview_title = true,

    path_display = {
      -- shorten directory names of everything but the last 3 parts
      -- foo/bar/baz/file.txt -> f/boo/bar/file.txt
      shorten = { len = 1, exclude = { -3, -2, -1 } },

      -- truncate the beginning of the file name if wider than the window
      truncate = true,
    },

    preview = {
      -- don't preview files larger than 1MB
      filesize_limit = 1,
      timeout = 500,
    },

    vimgrep_arguments = {
      -- defaults
      'rg',
      '--color=never',
      '--no-heading',
      '--with-filename',
      '--line-number',
      '--column',
      '--smart-case',
      -- search "hidden" files except git folder
      '--hidden',
      '--iglob=!.git'
    },

    -- ignore things we're likely not to edit
    file_ignore_patterns = {
      '%.zip$',
      '%.yarn/releases/',
      '%.yarn/plugins/'
    },

    -- picker history
    cache_picker = {
      num_pickers = 10,
    },
  },
  pickers = {
    buffers = {
      sort_lastused = true,
      sort_mru = true,
      mappings = {
        i = {
          ['<C-k>'] = 'delete_buffer'
        },
      },
    },
    find_files = {
      find_command = { 'fd', '--type', 'f', '--strip-cwd-prefix' }
    },
    git_commits = {
      mappings = commit_mappings,
    },
    git_bcommits = {
      mappings = commit_mappings,
    },
  },
  extensions = {
    ['ui-select'] = {
      telescope_themes.get_dropdown({})
    }
  }
})

-- use native sorter for better performance
telescope.load_extension('fzf')

-- use telescope for vim.ui.select
telescope.load_extension('ui-select')

-- custom picker to fallback to files if no git
local function project_files()
  local ok = pcall(telescope_builtin.git_files, { show_untracked = true })
  if not ok then telescope_builtin.find_files({}) end
end

-- custom picker for files within a commit
local function commit_files(opts)
  local resolved = util.resolve_git_path(0)
  if not resolved then
    vim.print('current file is not a fugitive path')
    return
  end

  opts = opts or {}
  telescope_pickers.new(opts, {
    prompt_title = resolved.commit,
    finder = telescope_finders.new_oneshot_job({ 'git', 'ls-tree', '--name-only', '-r', resolved.commit }, {
      entry_maker = function(entry)
        local path = string.format('fugitive://%s//%s/%s', resolved.repo, resolved.commit, entry)
        return {
          path = path,
          value = entry,
          display = entry,
          ordinal = entry,
        }
      end,
    }),
    sorter = telescope_conf.file_sorter(opts),

    -- the builtin previewer has fancy async loading which doesn't work for
    -- fugitive paths so we have to define our own
    previewer = telescope_previewers.new_buffer_previewer({
      title = function(self)
        return 'Commit Files'
      end,
      dyn_title = function(self, entry)
        return entry.value
      end,
      define_preview = function(self, entry, status)
        -- the builtin previewer does more things like using mime type
        -- fallbacks as well as binary file detection which ours doesn't do
        local ft = telescope_putils.filetype_detect(entry.value)

        vim.api.nvim_buf_call(self.state.bufnr, function()
          vim.cmd('Gread ' .. entry.path)
          telescope_putils.highlighter(self.state.bufnr, ft, opts)
        end)
      end,
    }),
  }):find()
end

vim.keymap.set('n', '<C-P>', project_files)
vim.keymap.set('n', '<C-O>', '<cmd>Telescope buffers<CR>')
vim.keymap.set('n', '<Leader>fg', commit_files)
vim.keymap.set('n', '<Leader>ff', '<cmd>Telescope live_grep<CR>')
vim.keymap.set('n', '<Leader>fr', '<cmd>Telescope resume<CR>')
vim.keymap.set('n', '<Leader>fp', '<cmd>Telescope pickers<CR>')