update lua API to 1-based indices; add renderer

lua/u/logger.lua

@@ -0,0 +1,69 @@
+local M = {}
+
+--- @params name string
+function M.file_for_name(name)
+  return vim.fs.joinpath(vim.fn.stdpath 'cache', 'u.log', name .. '.log.jsonl')
+end
+
+--------------------------------------------------------------------------------
+-- Logger class
+--------------------------------------------------------------------------------
+
+--- @class u.Logger
+--- @field name string
+--- @field private fd number
+local Logger = {}
+Logger.__index = Logger
+M.Logger = Logger
+
+--- @param name string
+function Logger.new(name)
+  local file_path = M.file_for_name(name)
+  vim.fn.mkdir(vim.fs.dirname(file_path), 'p')
+  local self = setmetatable({
+    name = name,
+    fd = (vim.uv or vim.loop).fs_open(file_path, 'a', tonumber('644', 8)),
+  }, Logger)
+  return self
+end
+
+--- @private
+--- @param level string
+function Logger:write(level, ...)
+  local data = { ... }
+  if #data == 1 then data = data[1] end
+  (vim.uv or vim.loop).fs_write(
+    self.fd,
+    vim.json.encode { ts = os.date(), level = level, data = data } .. '\n'
+  )
+end
+
+function Logger:trace(...) self:write('INFO', ...) end
+function Logger:debug(...) self:write('DEBUG', ...) end
+function Logger:info(...) self:write('INFO', ...) end
+function Logger:warn(...) self:write('WARN', ...) end
+function Logger:error(...) self:write('ERROR', ...) end
+
+function M.setup()
+  vim.api.nvim_create_user_command('Logfollow', function(args)
+    if #args.fargs == 0 then
+      vim.print 'expected log name'
+      return
+    end
+
+    local log_file_path = M.file_for_name(args.fargs[1])
+    vim.fn.mkdir(vim.fs.dirname(log_file_path), 'p')
+    vim.system({ 'touch', log_file_path }):wait()
+
+    vim.cmd.new()
+
+    local winnr = vim.api.nvim_get_current_win()
+    vim.wo[winnr][0].number = false
+    vim.wo[winnr][0].relativenumber = false
+
+    vim.cmd.terminal('tail -f "' .. log_file_path .. '"')
+    vim.cmd.startinsert()
+  end, { nargs = '*' })
+end
+
+return M