-- SPDX-FileCopyrightText: © 2026 Vladimir Zorin <vladimir@deviant.guru>
-- SPDX-License-Identifier: OWL-1.0 or later

local testimony = require("testimony")
local buffer = require("lem.buffer")
local motion = require("lem.motion")

local testify = testimony.new("== lem: motion ==")

local new_buf = function(text)
	local buf = buffer.new()
	buf:insert(0, text)
	return buf
end

testify:that("find_char_forward defaults count to 1", function()
	local buf = new_buf("abxcxdx")
	local line, col = motion.find_char_forward(buf, 1, 1, "x", false, 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(3, col)
end)

testify:that("find_char_forward honors count", function()
	local buf = new_buf("abxcxdx")
	local line, col = motion.find_char_forward(buf, 1, 1, "x", false, 8, 2)
	testimony.assert_equal(1, line)
	testimony.assert_equal(5, col)
end)

testify:that("find_char_forward till lands before counted match", function()
	local buf = new_buf("abxcxdx")
	local line, col = motion.find_char_forward(buf, 1, 1, "x", true, 8, 2)
	testimony.assert_equal(1, line)
	testimony.assert_equal(4, col)
end)

testify:that("find_char_backward honors count", function()
	local buf = new_buf("axbxcdx")
	local line, col = motion.find_char_backward(buf, 1, 7, "x", false, 8, 2)
	testimony.assert_equal(1, line)
	testimony.assert_equal(2, col)
end)

testify:that("find_char_backward till lands after counted match", function()
	local buf = new_buf("axbxcdx")
	local line, col = motion.find_char_backward(buf, 1, 7, "x", true, 8, 2)
	testimony.assert_equal(1, line)
	testimony.assert_equal(3, col)
end)

testify:that("find_char motions return nil when match count is unavailable", function()
	local buf = new_buf("abxc")
	local line = motion.find_char_forward(buf, 1, 1, "x", false, 8, 2)
	testimony.assert_nil(line)
	line = motion.find_char_backward(buf, 1, 4, "a", false, 8, 2)
	testimony.assert_nil(line)
end)

testify:that("word_forward moves across words punctuation and blank lines", function()
	local buf = new_buf("alpha, beta\n\n  gamma\n")
	local line, col = motion.word_forward(buf, 1, 1, 1, false, 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(6, col)
	line, col = motion.word_forward(buf, 1, 1, 2, false, 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(8, col)
	line, col = motion.word_forward(buf, 1, 1, 3, false, 8)
	testimony.assert_equal(2, line)
	testimony.assert_equal(1, col)
end)

testify:that("word_forward big treats punctuation as part of words", function()
	local buf = new_buf("alpha, beta\n")
	local line, col = motion.word_forward(buf, 1, 1, 1, true, 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(8, col)
end)

testify:that("word_backward crosses blank lines and stops at bof", function()
	local buf = new_buf("alpha beta\n\n  gamma\n")
	local line, col = motion.word_backward(buf, 3, 7, 1, false, 8)
	testimony.assert_equal(3, line)
	testimony.assert_equal(3, col)
	-- An empty line is a word stop (vim); leading whitespace is not
	line, col = motion.word_backward(buf, 3, 7, 2, false, 8)
	testimony.assert_equal(2, line)
	testimony.assert_equal(1, col)
	line, col = motion.word_backward(buf, 1, 1, 1, false, 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(1, col)
end)

testify:that("word_end reaches current next words and handles whitespace lines", function()
	local buf = new_buf("alpha beta\n   \ngamma\n")
	local line, col = motion.word_end(buf, 1, 1, 1, false, 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(5, col)
	line, col = motion.word_end(buf, 1, 1, 2, false, 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(10, col)
	line, col = motion.word_end(buf, 3, 5, 1, false, 8)
	testimony.assert_equal(4, line)
	testimony.assert_equal(1, col)
end)

testify:that("search_backward wraps around to matches below the cursor", function()
	local buf = new_buf("alpha\nbeta\nneedle here\n")
	-- Cursor on line 1: the only match is on line 3, reachable via wrap
	local line, col = motion.search_backward(buf, 1, 1, "needle", 8)
	testimony.assert_equal(3, line)
	testimony.assert_equal(1, col)
end)

testify:that("search_backward on the cursor line only matches before the cursor", function()
	local buf = new_buf("xx yy xx\n")
	local line, col = motion.search_backward(buf, 1, 7, "xx", 8)
	testimony.assert_equal(1, line)
	testimony.assert_equal(1, col)
end)

testify:that("paragraph motions land on blank lines", function()
	local buf = new_buf("one\ntwo\n\nthree\nfour\n\nfive\n")
	-- } from inside the first paragraph stops at the blank line 3
	testimony.assert_equal(3, motion.paragraph_forward(buf, 1, 1))
	-- } again: from the blank line, through paragraph two, to blank line 6
	testimony.assert_equal(6, motion.paragraph_forward(buf, 3, 1))
	-- { from inside paragraph two goes back to blank line 3
	testimony.assert_equal(3, motion.paragraph_backward(buf, 5, 1))
	-- { from the first paragraph stops at line 1
	testimony.assert_equal(1, motion.paragraph_backward(buf, 2, 1))
end)

testify:that("word_forward lands on first non-blank of an indented next line", function()
	local buf = new_buf("alpha\n  gamma\n")
	local line, col = motion.word_forward(buf, 1, 1, 1, false, 8)
	testimony.assert_equal(2, line)
	testimony.assert_equal(3, col)
end)

testify:that("word_forward skips whitespace-only lines", function()
	local buf = new_buf("alpha\n   \nbeta\n")
	local line, col = motion.word_forward(buf, 1, 1, 1, false, 8)
	testimony.assert_equal(3, line)
	testimony.assert_equal(1, col)
end)

testify:that("word_end crosses consecutive blank lines", function()
	local buf = new_buf("alpha\n\n\nbeta\n")
	local line, col = motion.word_end(buf, 1, 5, 1, false, 8)
	testimony.assert_equal(4, line)
	testimony.assert_equal(4, col)
end)

testify:conclude()