feat: add gomodifytags support

lua/gopher/_utils/init.lua

···
+return {
+  ---@param t table
+  ---@return boolean
+  empty = function(t)
+    if t == nil then
+      return true
+    end
+
+    return next(t) == nil
+  end,
+
+  ---@param s string
+  ---@return string
+  rtrim = function(s)
+    local n = #s
+    while n > 0 and s:find("^%s", n) do
+      n = n - 1
+    end
+
+    return s:sub(1, n)
+  end,
+}

lua/gopher/init.lua

···
+local tags = require "gopher.struct_tags"
 local gopher = {}
 
 gopher.install_deps = require("gopher.installer").install_all
+gopher.tags_add = tags.add
+gopher.tags_rm = tags.remove
 
 return gopher

lua/gopher/installer.lua

···
 local Job = require "plenary.job"
 local M = {
-  urls = {},
+  urls = {
+    gomodifytags = "github.com/fatih/gomodifytags",
+  },
 }
 
 local function install(pkg)

lua/gopher/struct_tags.lua

···
+local Job = require "plenary.job"
+local ts_utils = require "gopher._utils.ts"
+local utils = require "gopher._utils"
+local M = {}
+
+local function modify(...)
+  local fpath = vim.fn.expand "%" ---@diagnostic disable-line: missing-parameter
+  local ns = ts_utils.get_struct_node_at_pos(unpack(vim.api.nvim_win_get_cursor(0)))
+  if ns == nil or ns == {} then
+    return
+  end
+
+  -- stylua: ignore
+  local cmd_args = {
+    "-format", "json",
+    "-file", fpath,
+    "-w"
+  }
+
+  -- by struct name of line pos
+  if ns.name == nil then
+    local _, csrow, _, _ = unpack(vim.fn.getpos ".")
+    table.insert(cmd_args, "-line")
+    table.insert(cmd_args, csrow)
+  else
+    table.insert(cmd_args, "-struct")
+    table.insert(cmd_args, ns.name)
+  end
+
+  -- set user args for cmd
+  local arg = { ... }
+  for _, v in ipairs(arg) do
+    table.insert(cmd_args, v)
+  end
+
+  -- set default tag for "clear tags"
+  if #arg == 1 and arg[1] ~= "-clear-tags" then
+    table.insert(cmd_args, "json")
+  end
+
+  -- get result of "gomodifytags" works
+  local res_data
+  Job
+    :new({
+      command = "gomodifytags",
+      args = cmd_args,
+      on_exit = function(data, retval)
+        if retval ~= 0 then
+          print("command exited with code " .. retval)
+          return
+        end
+
+        res_data = data:result()
+      end,
+    })
+    :sync()
+
+  -- decode goted value
+  local tagged = vim.json.decode(table.concat(res_data))
+  if
+    tagged.errors ~= nil
+    or tagged.lines == nil
+    or tagged["start"] == nil
+    or tagged["start"] == 0
+  then
+    print("failed to set tags " .. vim.inspect(tagged))
+  end
+
+  for i, v in ipairs(tagged.lines) do
+    tagged.lines[i] = utils.rtrim(v)
+  end
+
+  -- write goted tags
+  vim.api.nvim_buf_set_lines(
+    0,
+    tagged.start - 1,
+    tagged.start - 1 + #tagged.lines,
+    false,
+    tagged.lines
+  )
+  vim.cmd "write"
+end
+
+---add tags to struct under cursor
+---@param ... unknown
+function M.add(...)
+  local arg = { ... }
+  if #arg == nil or arg == "" then
+    arg = { "json" }
+  end
+
+  local cmd_args = { "-add-tags" }
+  for _, v in ipairs(arg) do
+    table.insert(cmd_args, v)
+  end
+
+  modify(unpack(cmd_args))
+end
+
+---remove tags to struct under cursor
+---@param ... unknown
+function M.remove(...)
+  local arg = { ... }
+  if #arg == nil or arg == "" then
+    arg = { "json" }
+  end
+
+  local cmd_args = { "-remove-tags" }
+  for _, v in ipairs(arg) do
+    table.insert(cmd_args, v)
+  end
+
+  modify(unpack(cmd_args))
+end
+
+return M