From 05a65dab3ca5ca77729181f009f64b5ae94b0468 Mon Sep 17 00:00:00 2001
From: Jan Prochazka <jan.prochazka@gmail.com>
Date: Fri, 25 Jun 2021 17:04:01 +0200
Subject: [PATCH] alter plan

---
 packages/tools/src/alterPlan.ts | 117 ++++++++++++++++++++++++++++++++
 packages/tools/src/diffTools.ts |  65 +++++++++++++++++-
 2 files changed, 181 insertions(+), 1 deletion(-)
 create mode 100644 packages/tools/src/alterPlan.ts

diff --git a/packages/tools/src/alterPlan.ts b/packages/tools/src/alterPlan.ts
new file mode 100644
index 00000000..350d635b
--- /dev/null
+++ b/packages/tools/src/alterPlan.ts
@@ -0,0 +1,117 @@
+import { ColumnInfo, ConstraintInfo, DatabaseInfo, TableInfo } from '../../types';
+
+interface AlterOperation_CreateTable {
+  operationType: 'createTable';
+  newObject: TableInfo;
+}
+
+interface AlterOperation_DropTable {
+  operationType: 'dropTable';
+  oldObject: TableInfo;
+}
+
+interface AlterOperation_CreateColumn {
+  operationType: 'createColumn';
+  newObject: ColumnInfo;
+}
+
+interface AlterOperation_ChangeColumn {
+  operationType: 'changeColumn';
+  oldObject: ColumnInfo;
+  newObject: ColumnInfo;
+}
+
+interface AlterOperation_DropColumn {
+  operationType: 'dropColumn';
+  oldObject: ColumnInfo;
+}
+
+interface AlterOperation_CreateConstraint {
+  operationType: 'createConstraint';
+  newObject: ConstraintInfo;
+}
+
+interface AlterOperation_ChangeConstraint {
+  operationType: 'changeConstraint';
+  oldObject: ConstraintInfo;
+  newObject: ConstraintInfo;
+}
+
+interface AlterOperation_DropConstraint {
+  operationType: 'dropConstraint';
+  oldObject: ConstraintInfo;
+}
+
+type AlterOperation =
+  | AlterOperation_CreateColumn
+  | AlterOperation_ChangeColumn
+  | AlterOperation_DropColumn
+  | AlterOperation_CreateConstraint
+  | AlterOperation_ChangeConstraint
+  | AlterOperation_DropConstraint
+  | AlterOperation_CreateTable
+  | AlterOperation_DropTable;
+
+export class AlterPlan {
+  operations: AlterOperation[] = [];
+  constructor(public db: DatabaseInfo) {}
+
+  createTable(table: TableInfo) {
+    this.operations.push({
+      operationType: 'createTable',
+      newObject: table,
+    });
+  }
+
+  dropTable(table: TableInfo) {
+    this.operations.push({
+      operationType: 'dropTable',
+      oldObject: table,
+    });
+  }
+
+  createColumn(column: ColumnInfo) {
+    this.operations.push({
+      operationType: 'createColumn',
+      newObject: column,
+    });
+  }
+
+  changeColumn(oldColumn: ColumnInfo, newColumn: ColumnInfo) {
+    this.operations.push({
+      operationType: 'changeColumn',
+      oldObject: oldColumn,
+      newObject: newColumn,
+    });
+  }
+
+  dropColumn(column: ColumnInfo) {
+    this.operations.push({
+      operationType: 'dropColumn',
+      oldObject: column,
+    });
+  }
+
+  createConstraint(constraint: ConstraintInfo) {
+    this.operations.push({
+      operationType: 'createConstraint',
+      newObject: constraint,
+    });
+  }
+
+  changeConstraint(oldConstraint: ConstraintInfo, newConstraint: ConstraintInfo) {
+    this.operations.push({
+      operationType: 'changeConstraint',
+      oldObject: oldConstraint,
+      newObject: newConstraint,
+    });
+  }
+
+  dropConstraint(constraint: ConstraintInfo) {
+    this.operations.push({
+      operationType: 'dropConstraint',
+      oldObject: constraint,
+    });
+  }
+
+}
diff --git a/packages/tools/src/diffTools.ts b/packages/tools/src/diffTools.ts
index fe5a6075..cd0849a1 100644
--- a/packages/tools/src/diffTools.ts
+++ b/packages/tools/src/diffTools.ts
@@ -1,5 +1,13 @@
-import { ColumnInfo, TableInfo } from 'dbgate-types';
+import { ColumnInfo, DatabaseInfo, TableInfo } from 'dbgate-types';
 import uuidv1 from 'uuid/v1';
+import { AlterPlan } from './alterPlan';
+
+export interface DbDiffOptions {
+  allowRecreateTable: boolean;
+  allowRecreateConstraint: boolean;
+  allowRecreateSpecificObject: boolean;
+  allowPairRenamedTables: boolean;
+}
 
 export function generateTablePairingId(table: TableInfo): TableInfo {
   if (!table) return table;
@@ -27,3 +35,58 @@ export function generateTablePairingId(table: TableInfo): TableInfo {
   }
   return table;
 }
+
+function getTableConstraints(table: TableInfo) {
+  const res = [];
+  if (table.primaryKey) res.push(table.primaryKey);
+  if (table.foreignKeys) res.push(...table.foreignKeys);
+  if (table.indexes) res.push(...table.indexes);
+  if (table.checks) res.push(...table.checks);
+  return res;
+}
+
+function createPairs(oldList, newList, additionalCondition = null) {
+  const res = [];
+  for (const a of oldList) {
+    const b = newList.find(x => x.pairingId == a.pairingId || (additionalCondition && additionalCondition(a, b)));
+    if (b) {
+      res.push([a, b]);
+    } else {
+      res.push([a, null]);
+    }
+  }
+  for (const b of newList) {
+    if (!res.find(x => x[1] == b)) {
+      res.push([null, b]);
+    }
+  }
+  return res;
+}
+
+function planAlterTable(plan: AlterPlan, oldTable: TableInfo, newTable: TableInfo, options: DbDiffOptions) {
+  // if (oldTable.primaryKey)
+
+  const constraintPairs = createPairs(
+    getTableConstraints(oldTable),
+    getTableConstraints(newTable),
+    (a, b) => a.constraintType == 'primaryKey' && b.constraintType == 'primaryKey'
+  );
+  const columnPairs = createPairs(oldTable.columns, newTable.columns);
+
+  constraintPairs.filter(x => x[1] == null).forEach(x => plan.dropConstraint(x));
+}
+
+export function createAlterTablePlan(
+  oldTable: TableInfo,
+  newTable: TableInfo,
+  options: DbDiffOptions,
+  db: DatabaseInfo
+): AlterPlan {
+  const plan = new AlterPlan(db);
+  if (oldTable == null) {
+    plan.createTable(newTable);
+  } else {
+    planAlterTable(plan, oldTable, newTable, options);
+  }
+  return plan;
+}