From 7d7699474d888ae647cc048866882ec2c548f093 Mon Sep 17 00:00:00 2001
From: Oscar Wallberg <oscar.wallberg@outlook.com>
Date: Fri, 19 Apr 2024 17:22:28 +0200
Subject: [PATCH] feat(lsp): add format function

---
 lua/utils.lua | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)

diff --git a/lua/utils.lua b/lua/utils.lua
index e8ee00c..d8f638b 100644
--- a/lua/utils.lua
+++ b/lua/utils.lua
@@ -136,6 +136,138 @@ function M.try_require(module)
     M.err(("Failed to load module %s:\n%s"):format(module, resp))
 end
 
+---@class FormatOptions
+---@field cmd string[] Command to run. The following keywords get replaces by the specified values:
+---                    * %file%         - path to the current file
+---                    * %row_start%    - first row of selection
+---                    * %row_end%      - last row of selection
+---                    * %col_start%    - first column position of selection
+---                    * %col_end%      - last column position of selection
+---                    * %byte_start%   - byte count of first cell in selection
+---                    * %byte_end%     - byte count of last cell in selection
+---@field stdin boolean? Pass text to stdin. False by default.
+---@field stdout boolean? Use stdout as the result. False by default.
+---@field stderr boolean? Use stderr as the result. False by default.
+---@field in_place boolean? The file is formatted in-place by `cmd`. False by default.
+---@field auto_indent boolean? Perform auto indent on formatted range. False by default.
+---@field selection boolean? Only format the currently selected lines. False by default.
+
+--- Format buffer
+---@param opts FormatOptions
+function M.format(opts)
+    opts = {
+        cmd = opts.cmd,
+        stdin = opts.stdin or false,
+        stdout = opts.stdout or false,
+        stderr = opts.stderr or false,
+        in_place = opts.in_place or false,
+        auto_indent = opts.auto_indent or false,
+        selection = opts.selection or false,
+    }
+
+    if not opts.in_place and not opts.stdout and not opts.stderr then
+        M.err("One of `in_place`, `stdout` or `stderr` must be true.")
+        return
+    elseif opts.in_place and (opts.selection or opts.stdin or opts.stdout or opts.stderr) then
+        M.err(
+            "`in_place` is not valid together with any of "
+            .. "`selection`, `stdin`, `stdout` or `stderr`"
+        )
+        return
+    end
+
+    local file = vim.fn.expand("%")
+    local mode = vim.fn.mode()
+    local is_visual = mode == "v" or mode == "V" or mode == ""
+
+    local row_start, row_end, col_start, col_end, byte_start, byte_end
+    if is_visual then
+        row_start, col_start = unpack(vim.fn.getpos("v"), 2, 3)
+        row_end, col_end = unpack(vim.fn.getpos("."), 2, 3)
+
+        if row_start > row_end then
+            row_start, row_end, col_start, col_end = row_end, row_start, col_end, col_start
+        end
+
+        if mode == "V" then
+            col_start = 1
+            col_end = #vim.fn.getline(row_end)
+        end
+
+        byte_start = vim.fn.line2byte(row_start) + col_start - 1
+        byte_end = vim.fn.line2byte(row_end) + col_end - 1
+    end
+
+    local input
+    if opts.selection then
+        input = vim.api.nvim_buf_get_lines(0, row_start - 1, row_end, false)
+    else
+        input = vim.api.nvim_buf_get_lines(0, 0, -1, false)
+    end
+
+    if opts.in_place then
+        vim.api.nvim_buf_call(0, vim.cmd.write)
+    end
+
+    for i, arg in ipairs(opts.cmd) do
+        arg = arg:gsub("%%file%%", file)
+        if is_visual then
+            arg = arg:gsub("%%row_start%%", row_start)
+            arg = arg:gsub("%%row_end%%", row_end)
+            arg = arg:gsub("%%col_start%%", col_start)
+            arg = arg:gsub("%%col_end%%", col_end)
+            arg = arg:gsub("%%byte_start%%", byte_start)
+            arg = arg:gsub("%%byte_end%%", byte_end)
+        end
+        opts.cmd[i] = arg
+    end
+
+    vim.system(
+        opts.cmd,
+        {
+            stdin = opts.stdin and input or nil,
+        },
+        vim.schedule_wrap(function(out)
+            if out.code ~= 0 or out.signal ~= 0 then
+                local err = out.stderr or ""
+                M.err(("Failed to format:\n%s"):format(err))
+                return
+            end
+
+            if opts.in_place then
+                vim.api.nvim_buf_call(0, vim.cmd.edit)
+            else
+                local output
+                if opts.stdout then
+                    output = out.stdout or ""
+                end
+                if opts.stderr then
+                    output = out.stderr or ""
+                end
+
+                output = output:gsub("\n$", "")
+                local output_lines = vim.fn.split(output, "\n", true)
+
+                if opts.selection then
+                    vim.api.nvim_buf_set_lines(0, row_start - 1, row_end, false, output_lines)
+                else
+                    vim.api.nvim_buf_set_lines(0, 0, -1, false, output_lines)
+                end
+
+                if opts.auto_indent then
+                    if is_visual then
+                        vim.api.nvim_command(
+                            ("%d,%dnormal! =="):format(row_start, row_start + #output_lines)
+                        )
+                    else
+                        vim.api.nvim_command("normal! gg=G")
+                    end
+                end
+            end
+        end)
+    )
+end
+
 --- Check if `val` is a list of type `t` (if given)
 ---@param val any
 ---@param t type?