neovim: add keybinding to open commit under cursor in floating window

neovim/.config/nvim/after/plugin/remaps.lua

@@ -16,3 +16,5 @@ vim.keymap.set("n", "tn", ":tabnew<CR>")
 vim.keymap.set("n", "tN", ":-tabnew<CR>")
 vim.keymap.set("n", "H", ":tabprev<CR>")
 vim.keymap.set("n", "L", ":tabnext<CR>")
+
+vim.keymap.set("n", "<leader>gl", require("daniil.gitblame").open_blame_window)

neovim/.config/nvim/lua/daniil/gitblame.lua

@@ -0,0 +1,47 @@
+local u = require("daniil.utils")
+
+local M = {}
+
+---@param line number
+---@param path string
+---@return string
+local function get_commit_hash_at_line(line, path)
+  local cmd = vim.system({ "git", "blame", "-L", line .. "," .. line, "-p", "--", path }, { text = true }):wait()
+
+  local lines = {}
+  for s in cmd.stdout:gmatch("[^\r\n]+") do
+    table.insert(lines, s)
+  end
+
+  local commit_hash = lines[1]:gmatch("[^%s]+")() -- why I need to call this here but not above. i don't understand
+  return commit_hash
+end
+
+---@param hash string
+---@param dir string
+---@return string
+local function get_commit_info(hash, dir)
+  local cmd = vim.system({ "git", "-C", dir, "show", hash }, { text = true }):wait()
+  return cmd.stdout
+end
+
+function M.open_blame_window()
+  local cursor = vim.api.nvim_win_get_cursor(0)
+  local line = cursor[1]
+  local buf_name = vim.fn.expand("%:.")
+
+  local commit_hash = get_commit_hash_at_line(line, buf_name)
+  local commit_info = get_commit_info(commit_hash, vim.uv.cwd())
+
+  local bufnr, winnr = u.create_floating_window_in_center(0.75, 0.75)
+  u.set_buffer_text(bufnr, commit_info)
+
+  vim.bo[bufnr].filetype = "gitcommit"
+
+  vim.keymap.set("n", "<esc>", ":q<CR>", { buffer = bufnr })
+  vim.keymap.set("n", "q", ":q<CR>", { buffer = bufnr })
+
+  -- TODO: open not at the top of the buffer, but on line in OG file
+end
+
+return M

neovim/.config/nvim/lua/daniil/utils.lua

@@ -0,0 +1,43 @@
+local M = {}
+
+---@return number width, number height
+function M.get_terminal_size()
+  local width = vim.o.columns
+  local height = vim.o.lines
+  return width, height
+end
+
+---@param width number width in percentage of screen width (0.75, 0.5, etc)
+---@param height number height in percentage of screen height (0.75, 0.5, etc)
+---@return number buffer, number window
+function M.create_floating_window_in_center(width, height)
+  local bufnr = vim.api.nvim_create_buf(false, true) -- not listed, scratch buffer
+
+  local max_width, max_height = M.get_terminal_size()
+  local win_width = math.floor(max_width * width)
+  local win_height = math.floor(max_height * height)
+
+  local winnr = vim.api.nvim_open_win(bufnr, true, {
+    relative = "editor",
+    width = win_width,
+    height = win_height,
+    row = (max_height - win_height) / 2,
+    col = (max_width - win_width) / 2,
+    focusable = true,
+    style = "minimal",
+  })
+
+  return bufnr, winnr
+end
+
+---@param bufnr number
+---@param content string
+function M.set_buffer_text(bufnr, content)
+  local lines = {}
+  for s in content:gmatch("[^\r\n]+") do
+    table.insert(lines, s)
+  end
+  vim.api.nvim_buf_set_lines(bufnr, 0, vim.tbl_count(lines), false, lines)
+end
+
+return M