new telescope functionality and using fzf

lua/custom/line_telescope.lua

@@ -0,0 +1,105 @@
+local pickers = require("telescope.pickers")
+local finders = require("telescope.finders")
+local conf = require("telescope.config").values
+local actions = require("telescope.actions")
+local action_state = require("telescope.actions.state")
+local previewers = require("telescope.previewers")
+
+-- Custom previewer that dynamically calculates how many lines
+-- can fit in the preview window, then shows a centered slice.
+local dynamic_previewer = previewers.new_buffer_previewer({
+  define_preview = function(self, entry, status)
+    -- 'entry.lnum' is the *actual file line number*.
+    local filepath = entry.path
+    local target   = entry.lnum or 1
+
+    -- Get the preview buffer & window
+    local pbufnr = self.state.bufnr
+    local pwinid = status.preview_win
+    if not pbufnr or not vim.api.nvim_buf_is_valid(pbufnr) then
+      return
+    end
+    if not pwinid or not vim.api.nvim_win_is_valid(pwinid) then
+      return
+    end
+
+    -- How many lines can we show in the preview window?
+    -- Subtract a bit (e.g., 1 or 2) if you use borders or want extra margin.
+    local lines_in_window = vim.api.nvim_win_get_height(pwinid) - 1
+    if lines_in_window < 1 then
+      lines_in_window = 1
+    end
+
+    -- Read the entire file, figure out the slice to show
+    local all_lines = vim.fn.readfile(filepath)
+    local total = #all_lines
+
+    -- We'll center on the target line, if possible
+    local half_context = math.floor(lines_in_window / 2)
+    local start_line = math.max(target - half_context, 1)
+    local end_line = math.min(start_line + lines_in_window - 1, total)
+
+    -- Collect that slice of lines
+    local preview_lines = {}
+    for i = start_line, end_line do
+      table.insert(preview_lines, all_lines[i])
+    end
+
+    -- Write the slice to the preview buffer
+    vim.api.nvim_buf_set_lines(pbufnr, 0, -1, false, preview_lines)
+    vim.api.nvim_buf_clear_namespace(pbufnr, -1, 0, -1)
+
+    -- Highlight the target line within the slice
+    local relative_line = target - start_line + 1
+    if relative_line >= 1 and relative_line <= #preview_lines then
+      vim.api.nvim_buf_add_highlight(
+        pbufnr, -1, "Search", relative_line - 1, 0, -1
+      )
+    end
+  end,
+})
+
+local function jump_to_line()
+  local lines = vim.api.nvim_buf_get_lines(0, 0, -1, false)
+  local current_file = vim.api.nvim_buf_get_name(0)
+  local entries = {}
+
+  for i, text in ipairs(lines) do
+    table.insert(entries, {
+      value   = text,
+      display = string.format("%d: %s", i, text),
+      ordinal = text,
+      path    = current_file, -- needed by the previewer
+      lnum    = i,            -- actual file line number
+    })
+  end
+
+  pickers.new({}, {
+    prompt_title = "Jump to Line",
+    finder = finders.new_table({
+      results = entries,
+      entry_maker = function(e) return e end,
+    }),
+    sorter = conf.generic_sorter({}),
+    previewer = dynamic_previewer,
+    attach_mappings = function(prompt_bufnr, _)
+      actions.select_default:replace(function()
+        actions.close(prompt_bufnr)
+        local selection = action_state.get_selected_entry()
+        if selection then
+          local target_line = selection.lnum
+          local closed_line = vim.fn.foldclosed(target_line)
+          if closed_line ~= -1 then
+            target_line = closed_line
+          end
+          -- Jump and open the fold
+          vim.cmd(string.format("normal! %dG", target_line))
+          vim.cmd("normal! zv")
+        end
+      end)
+      return true
+    end,
+  }):find()
+end
+
+return { jump_to_line = jump_to_line }