local ls = require("luasnip")

local s = ls.snippet
local sn = ls.snippet_node
local t = ls.text_node
local i = ls.insert_node
local f = ls.function_node
local c = ls.choice_node
local d = ls.dynamic_node
local r = ls.restore_node
local l = require("luasnip.extras").lambda
local rep = require("luasnip.extras").rep
local p = require("luasnip.extras").partial
local m = require("luasnip.extras").match
local n = require("luasnip.extras").nonempty
local dl = require("luasnip.extras").dynamic_lambda
local fmt = require("luasnip.extras.fmt").fmt
local fmta = require("luasnip.extras.fmt").fmta
local conds = require("luasnip.extras.expand_conditions")

ls.config.set_config({
  history = true,
  update_events = "TextChanged,TextChangedI",
  delete_check_events = "TextChanged",
  ext_prio_increase = 1,
  enable_autosnippets = true,
  store_selection_keys = "<Tab>",
})

local function copy(args)
  return args[1]
end

local function bash(_, _, command)
  local file = io.popen(command, "r")
  local res = {}
  if file then
    for line in file:lines() do
      table.insert(res, line)
    end
  end
  return res
end

local date_input = function(args, snip, old_state, date_format)
  print(args, snip, old_state)
  return sn(nil, i(1, os.date(date_format or "%Y-%m-%d")))
end

-- -- FIXME: EXAMPLE
-- ls.add_snippets("all", {
--   -- arg1: trigger `fn`,
--   -- arg2: nodes to insert into buffer on expansion.
--   s("fn", {
--     t("//Parameters: "),    -- Text.
--     f(copy, 2),             -- 1: function, 2: placeholders to copy text from
--     t({ "", "function " }), -- placeholder/insert.
--     i(1),
--     t("("),                 -- placeholder with initial text.
--     i(2, "int foo"),        -- linebreak
--     t({ ") {", "\t" }),     -- last placeholder, snippet exit point
--     i(0),
--     t({ "", "}" }),
--   }),
--   s("class", {
--     -- Choice: Switch between two different Nodes, first parameter is its position, second a list of nodes.
--     c(1, {
--       t("public "),
--       t("private "),
--     }),
--     t("class "),
--     i(2),
--     t(" "),
--     c(3, {
--       t("{"),
--       -- sn: Nested Snippet. Instead of a trigger, it has a position, just like insert-nodes. !!! These don't expect a 0-node!!!!
--       -- Inside Choices, Nodes don't need a position as the choice node is the one being jumped to.
--       sn(nil, {
--         t("extends "),
--         -- restoreNode: stores and restores nodes.
--         -- pass position, store-key and nodes.
--         r(1, "other_class", i(1)),
--         t(" {"),
--       }),
--       sn(nil, {
--         t("implements "),
--         -- no need to define the nodes for a given key a second time.
--         r(1, "other_class"),
--         t(" {"),
--       }),
--     }),
--     t({ "", "\t" }),
--     i(0),
--     t({ "", "}" }),
--   }),
--   -- Alternative printf-like notation for defining snippets. It uses format
--   -- string with placeholders similar to the ones used with Python's .format().
--   s(
--     "fmt1",
--     fmt("To {title} {} {}.", {
--       i(2, "Name"),
--       i(3, "Surname"),
--       title = c(1, { t("Mr."), t("Ms.") }),
--     })
--   ),
--   -- To escape delimiters use double them, e.g. `{}` -> `{{}}`.
--   -- Multi-line format strings by default have empty first/last line removed.
--   -- Indent common to all lines is also removed. Use the third `opts` argument
--   -- to control this behaviour.
--   s(
--     "fmt2",
--     fmt(
--       [[
-- 		foo({1}, {3}) {{
-- 			return {2} * {4}
-- 		}}
-- 		]],
--       {
--         i(1, "x"),
--         rep(1),
--         i(2, "y"),
--         rep(2),
--       }
--     )
--   ),
--   -- Empty placeholders are numbered automatically starting from 1 or the last
--   -- value of a numbered placeholder. Named placeholders do not affect numbering.
--   s(
--     "fmt3",
--     fmt("{} {a} {} {1} {}", {
--       t("1"),
--       t("2"),
--       a = t("A"),
--     })
--   ),
--   -- The delimiters can be changed from the default `{}` to something else.
--   s("fmt4", fmt("foo() { return []; }", i(1, "x"), { delimiters = "[]" })),
--   -- `fmta` is a convenient wrapper that uses `<>` instead of `{}`.
--   s("fmt5", fmta("foo() { return <>; }", i(1, "x"))),
--   -- By default all args must be used. Use strict=false to disable the check
--   s(
--     "fmt6",
--     fmt("use {} only", { t("this"), t("not this") }, { strict = false })
--   ),
--   -- Use a dynamic_node to interpolate the output of a
--   -- function (see date_input above) into the initial
--   -- value of an insert_node.
--   s("novel", {
--     t("It was a dark and stormy night on "),
--     d(1, date_input, {}, { user_args = { "%A, %B %d of %Y" } }),
--     t(" and the clocks were striking thirteen."),
--   }),
--   -- Parsing snippets: First parameter: Snippet-Trigger, Second: Snippet body.
--   -- Placeholders are parsed into choices with 1. the placeholder text(as a snippet) and 2. an empty string.
--   -- This means they are not SELECTed like in other editors/Snippet engines.
--   ls.parser.parse_snippet(
--     "lspsyn",
--     "Wow! This ${1:Stuff} really ${2:works. ${3:Well, a bit.}}"
--   ),

--   -- When wordTrig is set to false, snippets may also expand inside other words.
--   ls.parser.parse_snippet(
--     { trig = "te", wordTrig = false },
--     "${1:cond} ? ${2:true} : ${3:false}"
--   ),

--   -- When regTrig is set, trig is treated like a pattern, this snippet will expand after any number.
--   ls.parser.parse_snippet({ trig = "%d", regTrig = true }, "A Number!!"),
--   -- Using the condition, it's possible to allow expansion only in specific cases.
--   s("cond", {
--     t("will only expand in c-style comments"),
--   }, {
--     condition = function(line_to_cursor, matched_trigger, captures)
--       -- optional whitespace followed by //
--       return line_to_cursor:match("%s*//")
--     end,
--   }),
--   -- there's some built-in conditions in "luasnip.extras.expand_conditions".
--   s("cond2", {
--     t("will only expand at the beginning of the line"),
--   }, {
--     condition = conds.line_begin,
--   }),
--   -- The last entry of args passed to the user-function is the surrounding snippet.
--   s(
--     { trig = "a%d", regTrig = true },
--     f(function(_, snip)
--       return "Triggered with " .. snip.trigger .. "."
--     end, {})
--   ),
--   -- It's possible to use capture-groups inside regex-triggers.
--   s(
--     { trig = "b(%d)", regTrig = true },
--     f(function(_, snip)
--       return "Captured Text: " .. snip.captures[1] .. "."
--     end, {})
--   ),
--   s({ trig = "c(%d+)", regTrig = true }, {
--     t("will only expand for even numbers"),
--   }, {
--     condition = function(line_to_cursor, matched_trigger, captures)
--       return tonumber(captures[1]) % 2 == 0
--     end,
--   }),
--   -- Use a function to execute any shell command and print its text.
--   s("bash", f(bash, {}, "ls")),
--   -- Short version for applying String transformations using function nodes.
--   s("transform", {
--     i(1, "initial text"),
--     t({ "", "" }),
--     -- lambda nodes accept an l._1,2,3,4,5, which in turn accept any string transformations.
--     -- This list will be applied in order to the first node given in the second argument.
--     l(l._1:match("[^i]*$"):gsub("i", "o"):gsub(" ", "_"):upper(), 1),
--   }),

--   s("transform2", {
--     i(1, "initial text"),
--     t("::"),
--     i(2, "replacement for e"),
--     t({ "", "" }),
--     -- Lambdas can also apply transforms USING the text of other nodes:
--     l(l._1:gsub("e", l._2), { 1, 2 }),
--   }),
--   s({ trig = "trafo(%d+)", regTrig = true }, {
--     -- env-variables and captures can also be used:
--     l(l.CAPTURE1:gsub("1", l.TM_FILENAME), {}),
--   }),
--   -- Set store_selection_keys = "<Tab>" (for example) in your
--   -- luasnip.config.setup() call to populate
--   -- TM_SELECTED_TEXT/SELECT_RAW/SELECT_DEDENT.
--   -- In this case: select a URL, hit Tab, then expand this snippet.
--   s("link_url", {
--     t('<a href="'),
--     f(function(_, snip)
--       -- TM_SELECTED_TEXT is a table to account for multiline-selections.
--       -- In this case only the first line is inserted.
--       return snip.env.TM_SELECTED_TEXT[1] or {}
--     end, {}),
--     t('">'),
--     i(1),
--     t("</a>"),
--     i(0),
--   }),
--   -- Shorthand for repeating the text in a given node.
--   s("repeat", { i(1, "text"), t({ "", "" }), rep(1) }),
--   -- Directly insert the ouput from a function evaluated at runtime.
--   s("part", p(os.date, "%Y")),
--   -- use matchNodes (`m(argnode, condition, then, else)`) to insert text
--   -- based on a pattern/function/lambda-evaluation.
--   -- It's basically a shortcut for simple functionNodes:
--   s("mat", {
--     i(1, { "sample_text" }),
--     t(": "),
--     m(1, "%d", "contains a number", "no number :("),
--   }),
--   -- The `then`-text defaults to the first capture group/the entire
--   -- match if there are none.
--   s("mat2", {
--     i(1, { "sample_text" }),
--     t(": "),
--     m(1, "[abc][abc][abc]"),
--   }),
--   -- It is even possible to apply gsubs' or other transformations
--   -- before matching.
--   s("mat3", {
--     i(1, { "sample_text" }),
--     t(": "),
--     m(
--       1,
--       l._1:gsub("[123]", ""):match("%d"),
--       "contains a number that isn't 1, 2 or 3!"
--     ),
--   }),
--   -- `match` also accepts a function in place of the condition, which in
--   -- turn accepts the usual functionNode-args.
--   -- The condition is considered true if the function returns any
--   -- non-nil/false-value.
--   -- If that value is a string, it is used as the `if`-text if no if is explicitly given.
--   s("mat4", {
--     i(1, { "sample_text" }),
--     t(": "),
--     m(1, function(args)
--       -- args is a table of multiline-strings (as usual).
--       return (#args[1][1] % 2 == 0 and args[1]) or nil
--     end),
--   }),
--   -- The nonempty-node inserts text depending on whether the arg-node is
--   -- empty.
--   s("nempty", {
--     i(1, "sample_text"),
--     n(1, "i(1) is not empty!"),
--   }),
--   -- dynamic lambdas work exactly like regular lambdas, except that they
--   -- don't return a textNode, but a dynamicNode containing one insertNode.
--   -- This makes it easier to dynamically set preset-text for insertNodes.
--   s("dl1", {
--     i(1, "sample_text"),
--     t({ ":", "" }),
--     dl(2, l._1, 1),
--   }),
--   -- Obviously, it's also possible to apply transformations, just like lambdas.
--   s("dl2", {
--     i(1, "sample_text"),
--     i(2, "sample_text_2"),
--     t({ "", "" }),
--     dl(3, l._1:gsub("\n", " linebreak ") .. l._2, { 1, 2 }),
--   }),
-- }, {
--   key = "all",
-- })

require("luasnip.loaders.from_lua").lazy_load({ paths = { "~/.config/nvim/snips" } })
require("luasnip.loaders.from_vscode").lazy_load({ paths = { "~/.config/Code - Insiders/User/snippets" } })