Diff.php generator

1@@ -1,6 +1,6 @@
2 <?php
3 /*
4- * Paste $v3.2 2025/09/07 https://github.com/boxlabss/PASTE
5+ * Paste $v3.2 2025/09/08 https://github.com/boxlabss/PASTE
6  * demo: https://paste.boxlabs.uk/
7  *
8  * https://phpaste.sourceforge.io/
9@@ -114,14 +114,15 @@
10 function _diff_idx_via_xdiff(array $A, array $B): array {
11     $N = count($A); $M = count($B);
12 
13-    // Join as text; ensure trailing newline to keep line counts exact
14+    // Join as text; add trailing newline to stabilize EOF handling
15     $left  = ($N ? implode("\n", $A) : '') . "\n";
16     $right = ($M ? implode("\n", $B) : '') . "\n";
17 
18-    // 0-context unified diff, non-minimal for speed
19-    $ud = xdiff_string_diff($left, $right, 0, false);
20+    // Use context for stable headers + ' ' lines; non-minimal for speed
21+    $ctx = 3;
22+    $ud = xdiff_string_diff($left, $right, $ctx, false);
23     if ($ud === false) {
24-        // Fallback to trivial equality handling
25+        // Trivial fallback: align common prefix, then tail adds/dels
26         $ops = [];
27         $eq = min($N, $M);
28         for ($i=0; $i<$eq; $i++) $ops[] = ['op'=>'eq','ai'=>$i,'bi'=>$i];
29@@ -131,9 +132,9 @@
30     }
31     if ($ud === '') {
32         $ops = [];
33-        for ($i=0; $i<$N && $i<$M; $i++) $ops[]=['op'=>'eq','ai'=>$i,'bi'=>$i];
34-        for ($i=$M; $i<$N; $i++) $ops[]=['op'=>'del','ai'=>$i];
35-        for ($j=$N; $j<$M; $j++) $ops[]=['op'=>'add','bi'=>$j];
36+        for ($i=0; $i<min($N,$M); $i++) $ops[] = ['op'=>'eq','ai'=>$i,'bi'=>$i];
37+        for ($i=$M; $i<$N; $i++) $ops[] = ['op'=>'del','ai'=>$i];
38+        for ($j=$N; $j<$M; $j++) $ops[] = ['op'=>'add','bi'=>$j];
39         return $ops;
40     }
41 
42@@ -144,25 +145,34 @@
43     foreach ($lines as $ln) {
44         if ($ln === '' && $ln !== '0') continue;
45 
46-        if (preg_match('/^@@\s+-([0-9]+)(?:,([0-9]+))?\s+\+([0-9]+)(?:,([0-9]+))?\s+@@/', $ln, $m)) {
47-            $startA = max(0, (int)$m[1] - 1); // 0-based
48+        // Hunk header: @@ -aStart,aLen +bStart,bLen @@
49+        if (($ln[0] ?? '') === '@' &&
50+            preg_match('/^@@\s+-([0-9]+)(?:,([0-9]+))?\s+\+([0-9]+)(?:,([0-9]+))?\s+@@/', $ln, $m)) {
51+
52+            $startA = max(0, (int)$m[1] - 1);  // convert to 0-based
53             $startB = max(0, (int)$m[3] - 1);
54-            // Emit equal block before this hunk (between current cursors and hunk start)
55-            $eq = min(max(0, $startA - $ai), max(0, $startB - $bi));
56-            for ($k=0; $k<$eq; $k++) { $ops[] = ['op'=>'eq','ai'=>$ai,'bi'=>$bi]; $ai++; $bi++; }
57+
58+            // Between hunks: move forward by equal lines only
59+            $gap = min(max(0, $startA - $ai), max(0, $startB - $bi));
60+            for ($k=0; $k<$gap; $k++) { $ops[] = ['op'=>'eq','ai'=>$ai,'bi'=>$bi]; $ai++; $bi++; }
61             continue;
62         }
63 
64         $tag = $ln[0] ?? '';
65-        if     ($tag === ' ') { $ops[] = ['op'=>'eq',  'ai'=>$ai,  'bi'=>$bi];  $ai++; $bi++; }
66-        elseif ($tag === '-') { $ops[] = ['op'=>'del', 'ai'=>$ai];              $ai++;        }
67-        elseif ($tag === '+') { $ops[] = ['op'=>'add',              'bi'=>$bi];         $bi++; }
68-        else {
69-            // headers '---', '+++', empty, etc > ignore
70+        if ($tag === ' ') {                   // context (equal)
71+            $ops[] = ['op'=>'eq','ai'=>$ai,'bi'=>$bi];  $ai++; $bi++;
72+        } elseif ($tag === '-') {             // deletion
73+            $ops[] = ['op'=>'del','ai'=>$ai];           $ai++;
74+        } elseif ($tag === '+') {             // addition
75+            $ops[] = ['op'=>'add','bi'=>$bi];                    $bi++;
76+        } elseif ($tag === '\\') {
77+            // "\ No newline at end of file" > ignore
78+        } else {
79+            // headers '---' / '+++' or noise > ignore
80         }
81     }
82 
83-    // Trailing equals after last hunk
84+    // Trailing equals after the last hunk
85     $tailEq = min($N - $ai, $M - $bi);
86     for ($k=0; $k<$tailEq; $k++) { $ops[] = ['op'=>'eq','ai'=>$ai,'bi'=>$bi]; $ai++; $bi++; }
87     for (; $ai<$N; $ai++) $ops[] = ['op'=>'del','ai'=>$ai];
88@@ -545,6 +555,66 @@
89 
90 $ops = diff_lines_idx($leftLines, $rightLines, $normalizer);
91 
92+/* ---------- change counts & exposure ----------
93+ * Treat an adjacent del-run followed by an add-run (or vice-versa) as "mods".
94+ * Each paired line counts as 1 change in the total.
95+ * Returns: [$adds, $dels, $mods, $total, $no_changes]
96+ */
97+function compute_change_counts(array $ops): array {
98+    $adds = 0; $dels = 0; $mods = 0;
99+    $n = count($ops);
100+    for ($i = 0; $i < $n; ) {
101+        $op = $ops[$i]['op'] ?? 'eq';
102+        if ($op !== 'add' && $op !== 'del') { $i++; continue; }
103+
104+        // First run (all adds or all dels)
105+        $t1 = $op;
106+        $c1 = 0;
107+        $j  = $i;
108+        while ($j < $n && ($ops[$j]['op'] ?? 'eq') === $t1) { $c1++; $j++; }
109+
110+        // Optional immediately-adjacent opposite run
111+        $t2 = ($t1 === 'add') ? 'del' : 'add';
112+        $c2 = 0;
113+        $k  = $j;
114+        while ($k < $n && ($ops[$k]['op'] ?? 'eq') === $t2) { $c2++; $k++; }
115+
116+        // Pair min(c1,c2) as modifications
117+        $pair = min($c1, $c2);
118+        $mods += $pair;
119+
120+        if ($t1 === 'add') {
121+            $adds += $c1 - $pair;
122+            $dels += $c2 - $pair;
123+        } else {
124+            $dels += $c1 - $pair;
125+            $adds += $c2 - $pair;
126+        }
127+
128+        // Advance past both runs
129+        $i = ($c2 > 0) ? $k : $j;
130+    }
131+
132+    $total = $adds + $dels + $mods;   // modified lines count as 1
133+    $no_changes = ($total === 0);
134+    return [$adds, $dels, $mods, $total, $no_changes];
135+}
136+
137+/* ---------- change counts (mods collapse -/+ into 1) ---------- */
138+[$adds, $dels, $mods, $changed_total, $no_changes] = compute_change_counts($ops);
139+
140+header('X-Diff-No-Changes: ' . ($no_changes ? '1' : '0'));
141+header('X-Diff-Change-Add: ' . $adds);
142+header('X-Diff-Change-Del: ' . $dels);
143+header('X-Diff-Change-Mod: ' . $mods);
144+header('X-Diff-Change-Total: ' . $changed_total);
145+
146+$GLOBALS['diff_no_changes']     = $no_changes;
147+$GLOBALS['diff_changes_add']    = $adds;
148+$GLOBALS['diff_changes_del']    = $dels;
149+$GLOBALS['diff_changes_mod']    = $mods;         // available if you want a separate badge
150+$GLOBALS['diff_changes_total']  = $changed_total; // theme uses this for ±T
151+
152 /* ---------- Build tables server-side ---------- */
153 [$sideRows, $uniRows] = build_tables_idx($ops, $leftLines, $rightLines);
154 
155@@ -579,7 +649,7 @@
156 // expose split pct to the view if needed by JS
157 $GLOBALS['split_pct'] = $split_pct;
158 
159-// Also expose new goodies for the toolbar (the theme may choose to use them)
160+// badges/toggle url for the theme
161 $GLOBALS['diff_engine_badge']  = $diff_engine_badge;
162 $GLOBALS['ignore_ws_on']       = $ignore_ws_on;
163 $GLOBALS['ignore_ws_toggle']   = $ignore_ws_toggle_url;