#!/bin/sh

# The diff page, unified or side-by-side under dt=1. The first checks read
# the markup for one added file in the fixture repository. The rest build
# repositories of their own, shaped for the side-by-side renderer's two
# trickiest cases, a hunk covering a single line and a file where every
# line changed.

test_description='Check content on diff page'
. ./setup.sh

test_expect_success 'generate foo/diff' 'cgit_url "foo/diff" >tmp'
test_expect_success 'find diff header' 'grep "a/file-5 b/file-5" tmp'
test_expect_success 'find blob link' 'grep "<a href=./foo/tree/file-5?id=" tmp'
test_expect_success 'find added file' 'grep "new file mode 100644" tmp'

test_expect_success 'find hunk header' '
	grep "<div class=.hunk.>@@ -0,0 +1 @@</div>" tmp
'

test_expect_success 'find added line' '
	grep "<div class=.add.>+5</div>" tmp
'

# The unified diff sits in a single cell, which holds the files together
# rather than tabulating them, so a screen reader is told it is layout.
test_expect_success 'the unified diff table is read as layout' '
	grep "<table class=.diff. role=.presentation.>" tmp
'

# A revision that names no commit is quoted the way the request wrote it, as
# the commit and patch pages quote it, on either side of the diff.
test_expect_success 'a tree on either side is named as the request gave it' '
	tree=$(git -C repos/foo rev-parse --short HEAD^{tree}) &&
	cgit_url "foo/diff/&id=$tree" >tmp &&
	grep "<div class=.error.>Not a commit: $tree</div>" tmp &&
	cgit_url "foo/diff/&id2=$tree" >tmp &&
	grep "<div class=.error.>Not a commit: $tree</div>" tmp
'

# git writes a hunk length only when the hunk spans more than one line, so the
# header for a single line reads "@@ -1 +1 @@" with no comma in it. Requiring
# that comma left those hunks numbered from zero, which dropped the line
# number link altogether.
test_expect_success 'set up a repo with single-line hunks' '
	mkrepo repos/hunk1 1 &&
	(
		cd repos/hunk1 &&
		printf "only\n" >one.txt &&
		git add one.txt &&
		git commit -m "add one.txt" &&
		printf "ONLY\n" >one.txt &&
		git commit -am "change one.txt"
	) &&
	cgitrc_repo hunk1rc hunk1 &&
	git -C repos/hunk1 diff HEAD~1 HEAD >raw.diff &&
	grep "^@@ -1 +1 @@" raw.diff
'

test_expect_success 'ssdiff numbers a comma-less hunk from its real line' '
	old=$(git -C repos/hunk1 rev-parse HEAD~1) &&
	new=$(git -C repos/hunk1 rev-parse HEAD) &&
	cgit_ok hunk1rc "url=hunk1/diff/&dt=1" >tmp &&
	grep "<a href=./hunk1/tree/one.txt?id=$old#n1.>1</a>" tmp &&
	grep "<a href=./hunk1/tree/one.txt?id=$new#n1.>1</a>" tmp
'

# A line dropped near the top leaves the two sides of the later hunk starting
# at different lines, so each side has to be numbered from its own half of the
# header.
test_expect_success 'set up a repo whose later hunk starts apart on each side' '
	mkrepo repos/later 1 &&
	(
		cd repos/later &&
		test_seq 1 20 >twenty.txt &&
		git add twenty.txt &&
		git commit -m "add twenty.txt" &&
		test_seq 1 20 | sed -e 2d -e s/^15$/fifteen/ >twenty.txt &&
		git commit -am "change twenty.txt"
	) &&
	cgitrc_repo laterrc later &&
	git -C repos/later diff HEAD~1 HEAD >raw.diff &&
	grep "^@@ -12,7 +11,7 @@" raw.diff
'

test_expect_success 'ssdiff numbers each side of a hunk from its own start' '
	old=$(git -C repos/later rev-parse HEAD~1) &&
	new=$(git -C repos/later rev-parse HEAD) &&
	cgit_ok laterrc "url=later/diff/&dt=1" >tmp &&
	grep -x "<td class=.lineno.><a href=./later/tree/twenty.txt?id=$old#n12.>12</a></td><td class=.ctx.>12</td>" tmp &&
	grep -x "<td class=.lineno.><a href=./later/tree/twenty.txt?id=$new#n11.>11</a></td><td class=.ctx.>12</td></tr>" tmp &&
	grep "<a href=./later/tree/twenty.txt?id=$old#n15.>15</a></td><td class=.changed.>" tmp &&
	grep "<a href=./later/tree/twenty.txt?id=$new#n14.>14</a></td><td class=.changed.>" tmp
'

# The character level highlight reuses one table across every changed pair, so
# these lines get shorter as the file goes on and each comparison is smaller
# than the one before it. That is where a cell left over from the previous
# pair shows itself, as a del or an add span sitting over the wrong
# characters.
test_expect_success 'set up a repo with shrinking changed lines' '
	mkrepo repos/lcs 1 &&
	(
		cd repos/lcs &&
		awk "BEGIN{for(n=120;n>0;n-=3){s=\"\";
			for(i=0;i<n;i++)s=s sprintf(\"%c\",97+(i*7+n)%26); print s}}" >lines.txt &&
		git add lines.txt &&
		git commit -m "add lines.txt" &&
		awk "BEGIN{for(n=120;n>0;n-=3){s=\"\";
			for(i=0;i<n;i++){c=97+(i*7+n)%26; if(i%7==0)c=97+(c-97+5)%26;
			s=s sprintf(\"%c\",c)} print s}}" >lines.txt &&
		git commit -am "change every line"
	) &&
	cgitrc_repo lcsrc lcs
'

# Each side of a row is written on a line of its own, the old side first and
# the new side closing the row.
test_expect_success 'every changed pair gets both a del and an add span' '
	cgit_ok lcsrc "url=lcs/diff/&dt=1" >tmp &&
	test $(grep -c "^<td class=.lineno.>.*<td class=.changed.>.*<span class=.del.>.*</td>$" tmp) -eq 40 &&
	test $(grep -c "^<td class=.lineno.>.*<td class=.changed.>.*<span class=.add.>.*</td></tr>$" tmp) -eq 40
'

test_expect_success 'stripping the highlight leaves each side its own lines' '
	cgit_ok lcsrc "url=lcs/diff/&dt=1" >tmp &&
	sed -n "s/^<td class=.lineno.><a [^>]*>[0-9]*<\/a><\/td><td class=.changed.>\(.*\)<\/td>$/\1/p" tmp |
		sed "s/<[^>]*>//g" >old.out &&
	sed -n "s/^<td class=.lineno.><a [^>]*>[0-9]*<\/a><\/td><td class=.changed.>\(.*\)<\/td><\/tr>$/\1/p" tmp |
		sed "s/<[^>]*>//g" >new.out &&
	git -C repos/lcs show HEAD~1:lines.txt >expect &&
	test_cmp expect old.out &&
	git -C repos/lcs show HEAD:lines.txt >expect &&
	test_cmp expect new.out
'

# Comparing the second pair below reads cells the first one wrote, and a cell
# left over from it would tip a tie there and mark the wrong characters.
test_expect_success 'a short pair after a longer one marks its own characters' '
	mkrepo repos/pair 1 &&
	(
		cd repos/pair &&
		test_write_lines bcde xa >pair.txt &&
		git add pair.txt &&
		git commit -m "add pair.txt" &&
		test_write_lines abcd ax >pair.txt &&
		git commit -am "change pair.txt"
	) &&
	cgitrc_repo pairrc pair &&
	cgit_ok pairrc "url=pair/diff/&dt=1" >tmp &&
	sed -n "s/^<td class=.lineno.><a [^>]*>[0-9]*<\/a><\/td>//p" tmp | tr -d "\047" >actual &&
	cat >expect <<-\EOF &&
	<td class=changed>bcd<span class=del>e</span></td>
	<td class=changed><span class=add>a</span>bcd</td></tr>
	<td class=changed><span class=del>x</span>a</td>
	<td class=changed>a<span class=add>x</span></td></tr>
	EOF
	test_cmp expect actual
'

# A file added or deleted fills one side, leaving the other a darker blank,
# and a changed pair with nothing in common is marked whole. Forced colours
# drop the backgrounds, so those cells keep a thicker border instead.
test_expect_success 'each side of a row is classed by what it holds' '
	cgit_ok_url "foo/diff&dt=1" >tmp &&
	grep -x "<td class=.lineno.></td><td class=.add-dark.></td>" tmp &&
	grep "<td class=.add.>5</td></tr>" tmp &&
	cgit_ok hunk1rc "url=hunk1/diff/&dt=1" >tmp &&
	grep "</a></td><td class=.changed.><span class=.del.>only</span></td>$" tmp &&
	grep "</a></td><td class=.changed.><span class=.add.>ONLY</span></td></tr>$" tmp
'

test_expect_success 'forced colours mark the changed cells with a border' '
	sed -n "/^@media (forced-colors: active) {$/,/^}/p" \
		"$TEST_OUTPUT_DIRECTORY/../assets/cgit.css" >rule &&
	sed -n "/^  div#cgit table.ssdiff td.add,$/,/^  }$/p" rule >cells &&
	grep "^  div#cgit table.ssdiff td.del,$" cells &&
	grep "^  div#cgit table.ssdiff td.changed {$" cells &&
	grep "^    border-left-width: 4px;$" cells
'

# Removals and additions that do not pair off are shown without marking,
# with a dark blank where a side runs out. A line past the comparison's
# limit is shown whole, a tab is expanded, and a binary file says so.
test_expect_success 'set up a commit for the remaining side-by-side rows' '
	mkrepo repos/cells 1 &&
	(
		cd repos/cells &&
		test_write_lines gone >gone.txt &&
		test_write_lines one two keep >uneven.txt &&
		printf "%0130d\n" 0 >long.txt &&
		printf "a\tb\nx\n" >tab.txt &&
		printf "\000old" >bin.dat &&
		git add . &&
		git commit -m "add the files" &&
		git rm -q gone.txt &&
		test_write_lines ONE keep >uneven.txt &&
		printf "%0129d1\n" 0 >long.txt &&
		printf "a\tb\ny\n" >tab.txt &&
		printf "\000new" >bin.dat &&
		git commit -am "change the files"
	) &&
	cgitrc_repo cellsrc cells
'

test_expect_success 'the remaining side-by-side rows' '
	cgit_ok cellsrc "url=cells/diff/&dt=1" >tmp &&
	grep "</a></td><td class=.del.>gone</td>$" tmp &&
	grep -x "<td class=.lineno.></td><td class=.del-dark.></td></tr>" tmp &&
	grep "</a></td><td class=.changed.>one</td>$" tmp &&
	grep "</a></td><td class=.changed.>ONE</td></tr>$" tmp &&
	grep "</a></td><td class=.changed.>two</td>$" tmp &&
	grep -x "<td class=.lineno.></td><td class=.changed-dark.></td></tr>" tmp &&
	grep "</a></td><td class=.changed.>$(printf "%0130d" 0)</td>$" tmp &&
	grep "</a></td><td class=.changed.>$(printf "%0129d1" 0)</td></tr>$" tmp &&
	grep "</a></td><td class=.ctx.>a       b</td>$" tmp &&
	grep "<tr><td colspan=.4.>Binary files differ</td></tr>" tmp
'

test_expect_success 'a side-by-side diff past max-diff-lines is cut short' '
	cgitrc_repo cellscaprc cells max-diff-lines=1 &&
	cgit_ok cellscaprc "url=cells/diff/&dt=1" >tmp &&
	grep "<tr><td colspan=.4. class=.truncated.>This diff is too large to be rendered inline. <a href=./cells/diff/long.txt?dt=1.>View it on its own page</a>.</td></tr>" tmp
'

# The diffstat links a renamed file by its new name, and so does the log of
# that file, but the old name lies outside a diff limited to the new one. That
# diff runs over the whole commit to find the rename, so the commit changes
# another file as well, which the limit still has to leave out.
test_expect_success 'set up a renamed file' '
	mkrepo repos/moved 1 &&
	(
		cd repos/moved &&
		test_seq 1 10 >old.txt &&
		git add old.txt &&
		git commit -m "add old.txt" &&
		git mv old.txt new.txt &&
		echo changed >file-1 &&
		git commit -am "rename old.txt"
	) &&
	cgitrc_repo movedrc moved
'

test_expect_success 'the diff of a renamed file shows the rename alone' '
	cgit_ok movedrc "url=moved/diff/new.txt" >tmp &&
	grep "diff --git a/old.txt b/new.txt" tmp &&
	grep "</a> (renamed from old.txt)</td>" tmp &&
	grep "<div class=.diffstat-summary.>1 file changed, 0 insertions, 0 deletions</div>" tmp &&
	! grep "new file mode" tmp &&
	! grep "a/file-1 b/file-1" tmp
'

test_expect_success 'so does the commit page limited to the new name' '
	cgit_ok movedrc "url=moved/commit/new.txt" >tmp &&
	grep "diff --git a/old.txt b/new.txt" tmp &&
	grep "<div class=.diffstat-summary.>1 file changed, 0 insertions, 0 deletions</div>" tmp &&
	! grep "new file mode" tmp &&
	! grep "a/file-1 b/file-1" tmp
'

# Following a file diffs the whole commit and keeps the pairs on that path,
# and the header still names the path rather than the empty limit the walk
# runs under.
test_expect_success 'a followed file is diffed as the rename alone' '
	cgitrc_repo followrc moved enable-follow-links=1 &&
	cgit_ok followrc "url=moved/diff/new.txt&follow=1" >tmp &&
	grep "diff --git a/old.txt b/new.txt" tmp &&
	grep "Diffstat</a> (limited to .new.txt.)</div>" tmp &&
	grep "<div class=.diffstat-summary.>1 file changed, 0 insertions, 0 deletions</div>" tmp &&
	! grep "a/file-1 b/file-1" tmp &&
	cgit_ok followrc "url=moved/commit/new.txt&follow=1" >tmp &&
	grep "diff --git a/old.txt b/new.txt" tmp &&
	grep "Diffstat</a> (limited to .new.txt.)</div>" tmp &&
	! grep "a/file-1 b/file-1" tmp
'

test_expect_success 'following with no path limits nothing' '
	cgit_ok followrc "url=moved/commit/&follow=1" >tmp &&
	grep "diff --git a/file-1 b/file-1" tmp &&
	grep "<div class=.diffstat-header.><a href=[^>]*>Diffstat</a></div>" tmp
'

test_expect_success 'a file added outright still shows as new' '
	added=$(git -C repos/moved rev-parse HEAD~1) &&
	cgit_ok movedrc "url=moved/diff/old.txt&id=$added" >tmp &&
	grep "new file mode 100644" tmp &&
	grep "<div class=.add.>+10</div>" tmp
'

test_done