404-solution / includes / uninstall / UninstallDatabaseMetadataReader.php

UninstallDatabaseMetadataReader.php in 404 Solution trunk, at includes/uninstall/UninstallDatabaseMetadataReader.php

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1	<?php
2	// allow-no-test-found: covered by tests/UninstallDiagnosticsEntryPointTest.php public uninstall modal/email entry points
3
4	if (!defined('ABSPATH')) {
5	exit;
6	}
7
8	/**
9	* Reads per-table metadata for uninstall diagnostics. Each table probe uses
10	* the production fallback chain: information_schema, SHOW TABLE STATUS,
11	* SHOW CREATE TABLE, then wpdb defaults.
12	*/
13	class ABJ_404_Solution_UninstallDatabaseMetadataReader {
14
15	/**
16	* @param string $tableName Table name to look up.
17	* @return array{charset?:string\|null,collation?:string\|null,engine?:string,error?:string,source?:string}
18	*/
19	public function getTableInfo(string $tableName): array {
20	$result = $this->tryInformationSchema($tableName);
21	if ($result !== null && !isset($result['error'])) {
22	return $result;
23	}
24
25	$result = $this->tryShowTableStatus($tableName);
26	if ($result !== null && !isset($result['error'])) {
27	return $result;
28	}
29
30	$result = $this->tryShowCreateTable($tableName);
31	if ($result !== null && !isset($result['error'])) {
32	return $result;
33	}
34
35	return $this->getWpdbDefaults();
36	}
37
38	/**
39	* @param string $tableName Table name to look up.
40	* @return array{charset?:string\|null,collation?:string\|null,engine?:string,error?:string}\|null
41	*/
42	public function tryInformationSchema(string $tableName) {
43	/** @var \wpdb $wpdb */
44	global $wpdb;
45
46	if (!method_exists($wpdb, 'get_row')) {
47	return array('error' => 'wpdb methods unavailable');
48	}
49
50	// DAO-bypass-approved: Diagnostic table charset/collation metadata probe.
51	$query = $wpdb->prepare(
52	"SELECT TABLE_COLLATION, ENGINE, " .
53	"SUBSTRING_INDEX(TABLE_COLLATION, '_', 1) as TABLE_CHARSET " .
54	"FROM information_schema.tables " .
55	"WHERE TABLE_NAME = %s AND TABLE_SCHEMA = DATABASE()",
56	$tableName
57	);
58
59	// DAO-bypass-approved: Diagnostic information_schema.tables probe
60	$result = $wpdb->get_row($query, ARRAY_A);
61
62	if (!empty($wpdb->last_error)) {
63	if (stripos($wpdb->last_error, 'denied') !== false \|\|
64	stripos($wpdb->last_error, 'permission') !== false) {
65	return array('error' => 'permission denied');
66	}
67	return array('error' => 'query error');
68	}
69
70	if (empty($result) \|\| !is_array($result)) {
71	return null;
72	}
73
74	$collation = $this->rowValue($result, 'TABLE_COLLATION');
75	$engine = $this->rowValue($result, 'ENGINE') ?: 'Unknown';
76	$charset = $this->rowValue($result, 'TABLE_CHARSET');
77
78	if (empty($charset) && !empty($collation)) {
79	$charset = explode('_', $collation)[0];
80	}
81
82	if (empty($collation)) {
83	return array('error' => 'no collation data');
84	}
85
86	return array(
87	'charset' => $charset,
88	'collation' => $collation,
89	'engine' => $engine
90	);
91	}
92
93	/**
94	* @param string $tableName Table name to look up.
95	* @return array{charset?:string\|null,collation?:string\|null,engine?:string,error?:string}\|null
96	*/
97	public function tryShowTableStatus(string $tableName) {
98	/** @var \wpdb $wpdb */
99	global $wpdb;
100
101	if (!method_exists($wpdb, 'get_row')) {
102	return array('error' => 'wpdb methods unavailable');
103	}
104
105	// DAO-bypass-approved: Diagnostic fallback metadata probe needs SHOW TABLE STATUS directly.
106	$result = $wpdb->get_row(
107	// DAO-bypass-approved: prepare() is part of diagnostic SHOW TABLE STATUS metadata probing.
108	$wpdb->prepare("SHOW TABLE STATUS LIKE %s", $tableName),
109	ARRAY_A
110	);
111
112	if (!empty($wpdb->last_error)) {
113	return array('error' => 'SHOW TABLE STATUS failed');
114	}
115
116	if (empty($result) \|\| !is_array($result)) {
117	return null;
118	}
119
120	$collation = $this->rowValue($result, 'Collation');
121	$engine = $this->rowValue($result, 'Engine') ?: 'Unknown';
122	$charset = (is_string($collation) && $collation !== '') ? explode('_', $collation)[0] : null;
123
124	if (empty($collation)) {
125	return null;
126	}
127
128	return array(
129	'charset' => $charset,
130	'collation' => $collation,
131	'engine' => $engine
132	);
133	}
134
135	/**
136	* @param string $tableName Table name to look up.
137	* @return array{charset?:string\|null,collation?:string\|null,engine?:string,error?:string}\|null
138	*/
139	public function tryShowCreateTable(string $tableName) {
140	/** @var \wpdb $wpdb */
141	global $wpdb;
142
143	if (!is_object($wpdb) \|\| !method_exists($wpdb, 'get_row')) {
144	return null;
145	}
146
147	// @utf8-audit: opt-out - $tableName is built from $wpdb->prefix plus
148	// 'abj404_*' constants by the uninstall flow; never user input.
149	// DAO-bypass-approved: Diagnostic last-resort SHOW CREATE TABLE charset parse
150	$result = $wpdb->get_row("SHOW CREATE TABLE `" . esc_sql($tableName) . "`", ARRAY_N);
151
152	if (empty($result[1])) {
153	return null;
154	}
155
156	$ddl = is_string($result[1]) ? $result[1] : '';
157
158	// Charset, collation and engine are all TABLE OPTIONS, which sit after
159	// the closing paren of the body. Column definitions come first in real
160	// engine output and a column may carry its own `CHARACTER SET x COLLATE
161	// y`, so a pattern run over the whole statement reports the first
162	// COLUMN's charset as the table's. This tier is the last one the
163	// uninstall diagnostics try, and what it returns is sent to the
164	// developer as the site's actual schema, so a confident wrong answer
165	// here sends a charset investigation after a fiction.
166	$tableDefault = ABJ_404_Solution_CreateTableOptionsParser::tableCharsetAndCollation($ddl);
167	if ($tableDefault === null) {
168	return null;
169	}
170
171	$charset = $tableDefault['charset'];
172	$collation = $tableDefault['collation'];
173	$engine = ABJ_404_Solution_CreateTableOptionsParser::tableEngine($ddl) ?? 'Unknown';
174
175	if ($charset && !$collation) {
176	$collation = $charset . '_general_ci';
177	}
178
179	if (empty($charset) && empty($collation)) {
180	return null;
181	}
182
183	return array(
184	'charset' => $charset ?: explode('_', $collation)[0],
185	'collation' => $collation,
186	'engine' => $engine
187	);
188	}
189
190	/**
191	* @return array{charset:string,collation:string,engine:string,source:string}
192	*/
193	public function getWpdbDefaults(): array {
194	global $wpdb;
195
196	$charset = 'utf8mb4';
197	$collation = 'utf8mb4_unicode_ci';
198
199	if (isset($wpdb->charset) && !empty($wpdb->charset)) {
200	$charset = $wpdb->charset;
201	} elseif (defined('DB_CHARSET') && DB_CHARSET) {
202	$charset = DB_CHARSET;
203	}
204
205	if (isset($wpdb->collate) && !empty($wpdb->collate)) {
206	$collation = $wpdb->collate;
207	}
208
209	return array(
210	'charset' => $charset,
211	'collation' => $collation,
212	'engine' => 'Unknown',
213	'source' => 'wpdb defaults'
214	);
215	}
216
217	/**
218	* @param array<array-key, mixed> $row
219	* @param string $key
220	* @return string\|null
221	*/
222	private function rowValue(array $row, string $key): ?string {
223	foreach ($row as $rowKey => $value) {
224	if (is_string($rowKey) && strcasecmp($rowKey, $key) === 0) {
225	return is_string($value) ? $value : null;
226	}
227	}
228	return null;
229	}
230	}
231