added typeaheead and introspetion

2026-10-18 17:18:14 +01:00
parent 7f6b63d05b
commit 8e5515afc0
3 changed files with 213 additions and 0 deletions
@@ -162,6 +162,77 @@ final class DatabaseModel: ObservableObject {
        }
    }

+    // Phase 66: compare bounded table samples without modifying either database.
+    struct DataComparisonReport {
+        let sourceRows: Int
+        let targetRows: Int
+        let truncated: Bool
+        let text: String
+    }
+
+    func compareTableData(source: String, target: String, table: String) async throws -> DataComparisonReport {
+        guard let profile = selected else {
+            throw NSError(domain: "DBSyn.DataCompare", code: 1, userInfo: [NSLocalizedDescriptionKey: "Connect to MySQL first."])
+        }
+        guard let sourceMetadata = introspection(for: source),
+              let targetMetadata = introspection(for: target),
+              sourceMetadata.tables.contains(table), targetMetadata.tables.contains(table) else {
+            throw NSError(domain: "DBSyn.DataCompare", code: 2, userInfo: [NSLocalizedDescriptionKey: "Introspect both databases and select a shared base table."])
+        }
+        let sourceColumns = (sourceMetadata.columnsByTable[table] ?? []).map(\.name)
+        let targetColumns = (targetMetadata.columnsByTable[table] ?? []).map(\.name)
+        guard !sourceColumns.isEmpty, sourceColumns == targetColumns else {
+            throw NSError(domain: "DBSyn.DataCompare", code: 3, userInfo: [NSLocalizedDescriptionKey: "The table columns must match in name and order before comparing data."])
+        }
+        func quote(_ identifier: String) -> String {
+            "`" + identifier.replacingOccurrences(of: "`", with: "``") + "`"
+        }
+        let password = PasswordStore.read(profile.id)
+        let sql = "SELECT * FROM \(quote(table)) LIMIT 501"
+        let left = try await NativeMySQLRunner.run(profile: profile, database: source, password: password, sql: sql)
+        let right = try await NativeMySQLRunner.run(profile: profile, database: target, password: password, sql: sql)
+        guard left.columns == right.columns else {
+            throw NSError(domain: "DBSyn.DataCompare", code: 4, userInfo: [NSLocalizedDescriptionKey: "Returned column layouts differ; comparison aborted."])
+        }
+        let limit = 500
+        let truncated = left.rows.count > limit || right.rows.count > limit
+        let a = Array(left.rows.prefix(limit))
+        let b = Array(right.rows.prefix(limit))
+        // JSON encoding gives unambiguous row keys, including embedded delimiters.
+        func counts(_ rows: [[String]]) -> [String: Int] {
+            var output: [String: Int] = [:]
+            for row in rows {
+                guard let bytes = try? JSONEncoder().encode(row),
+                      let key = String(data: bytes, encoding: .utf8) else { continue }
+                output[key, default: 0] += 1
+            }
+            return output
+        }
+        let leftCounts = counts(a)
+        let rightCounts = counts(b)
+        let keys = Set(leftCounts.keys).union(rightCounts.keys).sorted()
+        var lines = ["DBSyn Phase 66 — Read-only Table Data Comparison",
+                     "Source: \(source).\(table) — \(a.count) sampled rows",
+                     "Target: \(target).\(table) — \(b.count) sampled rows",
+                     "Columns: \(left.columns.joined(separator: ", "))", ""]
+        if truncated {
+            lines.append("WARNING: Truncated to 500 rows per side; without ORDER BY, MySQL does not guarantee which rows are returned. These results are not a complete or deterministic comparison.")
+            lines.append("")
+        }
+        var differences = 0
+        for key in keys {
+            let leftCount = leftCounts[key, default: 0]
+            let rightCount = rightCounts[key, default: 0]
+            if leftCount != rightCount {
+                differences += 1
+                lines.append("Source count \(leftCount), target count \(rightCount): \(key)")
+            }
+        }
+        if differences == 0 { lines.append("No differences detected in retrieved rows.") }
+        else { lines.insert("Distinct differing row values: \(differences)", at: 4) }
+        return DataComparisonReport(sourceRows: a.count, targetRows: b.count, truncated: truncated, text: lines.joined(separator: "\n"))
+    }
+
    @Published var selectedID: UUID?
    @Published var queryTabs: [WorkbenchQueryTab] = [
        WorkbenchQueryTab(