nvim/lua/snippets/snip_utils.lua

local ls = require 'luasnip'
local s = ls.snippet
local sn = ls.snippet_node
local fn = ls.function_node
local ms = ls.multi_snippet
local t = ls.text_node
local c = ls.choice_node
local i = ls.insert_node
local f = ls.function_node
local d = ls.dynamic_node
local fmt = require('luasnip.extras.fmt').fmt
local rep = require('luasnip.extras').rep
local line_begin = require('luasnip.extras.conditions').line_begin
local line_end = require('luasnip.extras.conditions').line_end
local extend_decorator = require 'luasnip.util.extend_decorator'
local fmta = extend_decorator.apply(fmt, { delimiters = '#~' })

local utils = {}

--- Check if the trigger is at the beginning of a line
---@param line_to_cursor string
---@param matched_trigger string
---@return boolean
utils.line_begin = function(line_to_cursor, matched_trigger)
    return line_to_cursor:sub(1, -(#matched_trigger + 1)):match '^%s*$'
end

--- Check if the trigger is on an empty line
---@param _ string
---@param matched_trigger string
---@return boolean
utils.empty_line = function(_, matched_trigger)
    return vim.api.nvim_get_current_line():match('^%s*' .. vim.pesc(matched_trigger) .. '$')
end

--- Check if the trigger is at the start of a file
---@param line_to_cursor string
---@param matched_trigger string
---@return boolean
utils.file_begin = function(line_to_cursor, matched_trigger)
    local line_number = vim.fn.line '.'
    return line_number == 1 and line_begin(line_to_cursor, matched_trigger)
end

--- Check if the trigger is inside a string
---@return boolean
utils.in_string = function()
    local node_type = vim.treesitter.get_node():type()
    return node_type == 'string_content' or node_type == 'string'
end

--- Check if the trigger is inside a comment
---@return boolean
utils.in_comment = function()
    local node_type = vim.treesitter.get_node():type()
    return node_type == 'comment'
end

--- Check if the trigger is not inside a string or a comment
---@return boolean
utils.not_in_string_or_comment = function()
    return (not utils.in_string()) and (not utils.in_comment())
end

--- Create a basic auto expand trigger
---@param trigger string
---@param description? string
---@param options? table
---@return table
utils.tr = function(trigger, description, options)
    return vim.tbl_extend('force', {
        trig = trigger,
        desc = description,
        snippetType = 'autosnippet',
    }, options or {})
end

--- Create a trigger for an empty line snippet
---@param trigger string
---@param description? string
---@param options? table
---@return table
utils.etr = function(trigger, description, options)
    return utils.tr(trigger, description, vim.tbl_extend('force', { condition = utils.empty_line }, options or {}))
end

--- Create a trigger for a comment trigger
---@param trigger string
---@param description? string
---@param options? table
---@return table
utils.ctr = function(trigger, description, options)
    return utils.tr(trigger, description, vim.tbl_extend('force', { condition = utils.in_comment }, options or {}))
end

--- Create a trigger for a snippet to expand anywhere outside a string/comment
---@param trigger string
---@param description? string
---@param options? table
---@return table
utils.atr = function(trigger, description, options)
    return utils.tr(
        trigger,
        description,
        vim.tbl_extend('force', {
            regTrig = true,
            wordTrig = false,
            condition = utils.not_in_string_or_comment,
        }, options or {})
    )
end

--- Create a trigger for a snippet to expand at the end of a line
---@param trigger string
---@param description? string
---@param options? table
---@return table
utils.Etr = function(trigger, description, options)
    return utils.tr(
        trigger,
        description,
        vim.tbl_extend('force', {
            condition = line_end
        }, options or {})
    )
end

--- Create a snippet that will expand anywhere but in the middle of a word
---@param trigger any
---@param nodes any
---@param options? any
---@return table
utils.bs = function(trigger, nodes, options)
    local btrigger
    if type(trigger) == 'string' then
        btrigger = utils.atr('([^%w_-])' .. trigger)
    else
        btrigger = vim.tbl_extend('keep', utils.atr('([^%w_-])' .. trigger.trig), trigger)
    end
    return ms(
        {
            trigger,
            btrigger,
        },
        vim.list_extend({ fn(function(args, snip)
            return snip.captures[1] or ''
        end) }, nodes),
        options
    )
end

return utils