From 6fd413c4c2053e718be69fb816a94ce8322f0f21 Mon Sep 17 00:00:00 2001
From: Smirnov Olexander <ss2316544@gmail.com>
Date: Wed, 15 Jun 2022 12:44:04 +0300
Subject: [PATCH] feat: add impl support

docs: add impl
---
 README.md                | 34 ++++++++++++++----
 lua/gopher/impl.lua      | 74 ++++++++++++++++++++++++++++++++++++++++
 lua/gopher/init.lua      |  1 +
 lua/gopher/installer.lua |  1 +
 plugin/gopher.vim        |  1 +
 5 files changed, 104 insertions(+), 7 deletions(-)
 create mode 100644 lua/gopher/impl.lua

diff --git a/README.md b/README.md
index f02f3ea..c48dcfc 100644
--- a/README.md
+++ b/README.md
@@ -23,25 +23,27 @@ Also, run `TSInstall go` if install the `go` parser if not installed yet.
 ## Features
 
 1. Install requires go tools:
+
+```vim
+:GoInstallDeps
+```
+
 This will install next tools:
 
 - [gomodifytags](https://github.com/fatih/gomodifytags)
-
-```viml
-:GoInstallDeps
-```
+- [impl](https://github.com/josharian/impl)
 
 2. Modify struct tags:
 By default be added/removed `json` tag, if not set.
 
-```viml
+```vim
 :GoTagAdd json " For add json tag
 :GoTagRm yaml " For remove yaml tag
 ```
 
 3. Run `go mod` command
 
-```viml
+```vim
 :GoMod tidy " Runs `go mod tidy`
 :GoMod init asdf " Runs `go mod init asdf`
 ```
@@ -52,10 +54,28 @@ Link can has a `http` or `https` prefix.
 
 You can provide more that one package url.
 
-```viml
+```vim
 :GoGet github.com/gorilla/mux
 ```
 
+5. Interface implementation
+
+Command syntax:
+```vim
+:GoImpl [receiver] [interface]
+
+" Also you can put cursor on the struct and run:
+:GoImpl [interface]
+```
+
+Example of usage:
+```vim
+" Example
+:GoImpl r Read io.Reader
+" or simply put your cursor in the struct and run:
+:GoImpl io.Reader
+```
+
 ## Thanks
 
 - [go.nvim](https://github.com/ray-x/go.nvim)
diff --git a/lua/gopher/impl.lua b/lua/gopher/impl.lua
new file mode 100644
index 0000000..b19c84a
--- /dev/null
+++ b/lua/gopher/impl.lua
@@ -0,0 +1,74 @@
+local Job = require "plenary.job"
+local ts_utils = require "gopher._utils.ts"
+
+local function get_struct()
+  local ns = ts_utils.get_struct_node_at_pos(unpack(vim.api.nvim_win_get_cursor(0)))
+  if ns == nil then
+    print "put cursor on struct or specify a receiver"
+    return ""
+  end
+
+  vim.api.nvim_win_set_cursor(0, {
+    ns.dim.e.r,
+    ns.dim.e.c,
+  })
+
+  return ns.name
+end
+
+return function(...)
+  local args = { ... }
+  local iface, recv_name = "", ""
+  local recv = get_struct()
+
+  if #args == 0 then
+    iface = vim.fn.input "impl: generating method stubs for interface: "
+    vim.cmd "redeaw!"
+    if iface == "" then
+      print "usage: GoImpl f *File io.Reader"
+    end
+  elseif #args == 1 then -- :GoImpl io.Reader
+    recv = string.lower(recv) .. " *" .. recv
+    vim.cmd "redraw!"
+    iface = select(1, ...)
+  elseif #args == 2 then -- :GoImpl w io.Writer
+    recv_name = select(1, ...)
+    recv = string.format("%s *%s", recv_name, recv)
+    iface = select(#args, ...)
+  elseif #args > 2 then
+    iface = select(#args, ...)
+    recv = select(#args - 1, ...)
+    recv_name = select(#args - 2, ...)
+    recv = string.format("%s %s", recv_name, recv)
+  end
+
+  -- stylua: ignore
+  local cmd_args = {
+    "-dir", vim.fn.fnameescape(vim.fn.expand "%:p:h"), ---@diagnostic disable-line: missing-parameter
+    recv,
+    iface
+  }
+
+  local res_data
+  Job
+    :new({
+      command = "impl",
+      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()
+
+  local pos = vim.fn.getcurpos()[2]
+  table.insert(res_data, 1, "")
+  vim.fn.append(pos, res_data)
+
+  -- table.insert(res_data, 1, "")
+  -- vim.fn.append(vim.fn.getcurpos()[2], res_data)
+end
diff --git a/lua/gopher/init.lua b/lua/gopher/init.lua
index c01abc4..3ada8c4 100644
--- a/lua/gopher/init.lua
+++ b/lua/gopher/init.lua
@@ -6,5 +6,6 @@ gopher.tags_add = tags.add
 gopher.tags_rm = tags.remove
 gopher.mod = require "gopher.gomod"
 gopher.get = require "gopher.goget"
+gopher.impl = require "gopher.impl"
 
 return gopher
diff --git a/lua/gopher/installer.lua b/lua/gopher/installer.lua
index c1213c5..6e0bd87 100644
--- a/lua/gopher/installer.lua
+++ b/lua/gopher/installer.lua
@@ -2,6 +2,7 @@ local Job = require "plenary.job"
 local M = {
   urls = {
     gomodifytags = "github.com/fatih/gomodifytags",
+    impl = "github.com/josharian/impl",
   },
 }
 
diff --git a/plugin/gopher.vim b/plugin/gopher.vim
index 1e68e0a..caeeb80 100644
--- a/plugin/gopher.vim
+++ b/plugin/gopher.vim
@@ -2,4 +2,5 @@ command! -nargs=* GoTagAdd :lua require"gopher".tags_add(<f-args>)
 command! -nargs=* GoTagRm :lua require"gopher".tags_rm(<f-args>)
 command! -nargs=* GoMod :lua require"gopher".mod(<f-args>)
 command! -nargs=* GoGet :lua require"gopher".get(<f-args>)
+command! -nargs=* GoImpl :lua require"gopher".impl(<f-args>)
 command! GoInstallDeps :lua require"gopher".install_deps()