u.nvim/lua/u/utils.lua

local M = {}

--
-- Types
--

--- @class u.utils.QfItem
--- @field col number
--- @field filename string
--- @field kind string
--- @field lnum number
--- @field text string

--- @class u.utils.RawCmdArgs
--- @field args string
--- @field bang boolean
--- @field count number
--- @field fargs string[]
--- @field line1 number
--- @field line2 number
--- @field mods string
--- @field name string
--- @field range 0|1|2
--- @field reg string
--- @field smods any

--- @class u.utils.CmdArgs: u.utils.RawCmdArgs
--- @field info u.Range|nil

--- @class u.utils.UcmdArgs
--- @field nargs? 0|1|'*'|'?'|'+'
--- @field range? boolean|'%'|number
--- @field count? boolean|number
--- @field addr? string
--- @field completion? string
--- @field force? boolean
--- @field preview? fun(opts: u.utils.UcmdArgs, ns: integer, buf: integer):0|1|2

--
-- Functions
--

--- Debug utility that prints a value and returns it unchanged.
--- Useful for debugging in the middle of expressions or function chains.
---
--- @generic T
--- @param x `T` The value to debug print
--- @param message? string Optional message to print alongside the value
--- @return T The original value, unchanged
---
--- @usage
--- ```lua
--- -- Debug a value in the middle of a chain:
--- local result = some_function()
---   :map(utils.dbg)  -- prints the intermediate value
---   :filter(predicate)
---
--- -- Debug with a custom message:
--- local config = utils.dbg(get_config(), "Current config:")
---
--- -- Debug return values:
--- return utils.dbg(calculate_result(), "Final result")
--- ```
function M.dbg(x, message)
  local t = {}
  if message ~= nil then table.insert(t, message) end
  table.insert(t, x)
  vim.print(t)
  return x
end

--- Creates a user command with enhanced argument processing.
--- Automatically computes range information and attaches it as `args.info`.
---
--- @param name string The command name (without the leading colon)
--- @param cmd string | fun(args: u.utils.CmdArgs): any Command implementation
--- @param opts? u.utils.UcmdArgs Command options (nargs, range, etc.)
---
--- @usage
--- ```lua
--- -- Create a command that works with visual selections:
--- utils.ucmd('MyCmd', function(args)
---   -- Print the visually selected text:
---   vim.print(args.info:text())
---   -- Or get the selection as an array of lines:
---   vim.print(args.info:lines())
--- end, { nargs = '*', range = true })
---
--- -- Create a command that processes the current line:
--- utils.ucmd('ProcessLine', function(args)
---   local line_text = args.info:text()
---   -- Process the line...
--- end, { range = '%' })
---
--- -- Create a command with arguments:
--- utils.ucmd('SearchReplace', function(args)
---   local pattern, replacement = args.fargs[1], args.fargs[2]
---   local text = args.info:text()
---   -- Perform search and replace...
--- end, { nargs = 2, range = true })
--- ```
-- luacheck: ignore
function M.ucmd(name, cmd, opts)
  local Range = require 'u.range'

  opts = opts or {}
  local cmd2 = cmd
  if type(cmd) == 'function' then
    cmd2 = function(args)
      args.info = Range.from_cmd_args(args)
      return cmd(args)
    end
  end
  vim.api.nvim_create_user_command(name, cmd2, opts or {} --[[@as any]])
end

--- Creates command arguments for delegating from one command to another.
--- Preserves all relevant context (range, modifiers, bang, etc.) when
--- implementing a derived command in terms of a base command.
---
--- @param current_args vim.api.keyset.create_user_command.command_args|u.utils.RawCmdArgs The arguments from the current command
--- @return vim.api.keyset.cmd Arguments suitable for vim.cmd() calls
---
--- @usage
--- ```lua
--- -- Implement :MyEdit in terms of :edit, preserving all context:
--- utils.ucmd('MyEdit', function(args)
---   local delegated_args = utils.create_delegated_cmd_args(args)
---   -- Add custom logic here...
---   vim.cmd.edit(delegated_args)
--- end, { nargs = '*', range = true, bang = true })
---
--- -- Implement :MySubstitute that delegates to :substitute:
--- utils.ucmd('MySubstitute', function(args)
---   -- Pre-process arguments
---   local pattern = preprocess_pattern(args.fargs[1])
---
---   local delegated_args = utils.create_delegated_cmd_args(args)
---   delegated_args.args = { pattern, args.fargs[2] }
---
---   vim.cmd.substitute(delegated_args)
--- end, { nargs = 2, range = true, bang = true })
--- ```
function M.create_delegated_cmd_args(current_args)
  --- @type vim.api.keyset.cmd
  local args = {
    range = current_args.range == 1 and { current_args.line1 }
      or current_args.range == 2 and { current_args.line1, current_args.line2 }
      or nil,
    count = current_args.count ~= -1 and current_args.count or nil,
    reg = current_args.reg ~= '' and current_args.reg or nil,
    bang = current_args.bang or nil,
    args = #current_args.fargs > 0 and current_args.fargs or nil,
    mods = current_args.smods,
  }
  return args
end

--- Gets the current editor dimensions.
--- Useful for positioning floating windows or calculating layout sizes.
---
--- @return { width: number, height: number } The editor dimensions in columns and lines
---
--- @usage
--- ```lua
--- -- Center a floating window:
--- local dims = utils.get_editor_dimensions()
--- local win_width = 80
--- local win_height = 20
--- local col = math.floor((dims.width - win_width) / 2)
--- local row = math.floor((dims.height - win_height) / 2)
---
--- vim.api.nvim_open_win(bufnr, true, {
---   relative = 'editor',
---   width = win_width,
---   height = win_height,
---   col = col,
---   row = row,
--- })
---
--- -- Check if editor is wide enough for side-by-side layout:
--- local dims = utils.get_editor_dimensions()
--- if dims.width >= 160 then
---   -- Use side-by-side layout
--- else
---   -- Use stacked layout
--- end
--- ```
function M.get_editor_dimensions() return { width = vim.go.columns, height = vim.go.lines } end

return M