Fix sqlite build on Windows

Author: simolus3

.github/workflows/tests.yml

@@ -126,7 +126,7 @@ jobs:
     name: Testing on ${{ matrix.os }}
     if: github.event_name == 'push' || (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name != github.repository)
     runs-on: ${{ matrix.os }}
-    needs: [libs_linux, libs_macos]
+    needs: [libs_linux, libs_macos, libs_windows]
     strategy:
       fail-fast: false
       matrix:

dart/pubspec.lock

@@ -17,6 +17,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "7.5.6"
+  archive:
+    dependency: "direct dev"
+    description:
+      name: archive
+      sha256: "2fde1607386ab523f7a36bb3e7edb43bd58e6edaf2ffb29d8a6d578b297fdbbd"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.7"
   args:
     dependency: transitive
     description:
@@ -153,6 +161,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.3"
+  http:
+    dependency: "direct dev"
+    description:
+      name: http
+      sha256: bb2ce4590bc2667c96f318d68cac1b5a7987ec819351d32b1c987239a815e007
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.5.0"
   http_multi_server:
     dependency: transitive
     description:
@@ -265,6 +281,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.5.1"
+  posix:
+    dependency: transitive
+    description:
+      name: posix
+      sha256: "6323a5b0fa688b6a010df4905a56b00181479e6d10534cecfecede2aa55add61"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.0.3"
   power_extensions:
     dependency: transitive
     description:

dart/pubspec.yaml

@@ -17,3 +17,5 @@ dev_dependencies:
   convert: ^3.1.2
   meta: ^1.16.0
   path: ^1.9.1
+  http: ^1.5.0
+  archive: ^4.0.7

dart/tool/download_sqlite3.dart

@@ -1,6 +1,8 @@
 import 'dart:io';
 
+import 'package:archive/archive_io.dart';
 import 'package:path/path.dart' as p;
+import 'package:http/http.dart';
 
 typedef SqliteVersion = ({String version, String year});
 
@@ -21,6 +23,9 @@ Future<void> main(List<String> args) async {
 extension on SqliteVersion {
   String get autoconfUrl =>
       'https://sqlite.org/$year/sqlite-autoconf-$version.tar.gz';
+
+  String get windowsUrl =>
+      'https://sqlite.org/$year/sqlite-dll-win-x64-$version.zip';
 }
 
 Future<void> _downloadAndCompile(String name, SqliteVersion version,
@@ -52,6 +57,38 @@ Future<void> _downloadAndCompile(String name, SqliteVersion version,
       await Directory.systemTemp.createTemp('powersync-core-compile-sqlite3');
   final temporaryDirPath = temporaryDir.path;
 
+  // Compiling on Windows is ugly because we need users to have Visual Studio
+  // installed and all those tools activated in the current shell.
+  // Much easier to just download precompiled builds.
+  if (Platform.isWindows) {
+    final windowsUri = version.windowsUrl;
+    final sqlite3Zip = p.join(temporaryDirPath, 'sqlite3.zip');
+    final client = Client();
+    final response = await client
+        .send(Request('GET', Uri.parse(windowsUri))..followRedirects = true);
+    if (response.statusCode != 200) {
+      print(
+          'Could not download $windowsUri, status code ${response.statusCode}');
+      exit(1);
+    }
+    await response.stream.pipe(File(sqlite3Zip).openWrite());
+
+    final inputStream = InputFileStream(sqlite3Zip);
+    final archive = ZipDecoder().decodeStream(inputStream);
+
+    for (final file in archive.files) {
+      if (file.isFile && file.name == 'sqlite3.dll') {
+        final outputStream = OutputFileStream(p.join(target, 'sqlite3.dll'));
+
+        file.writeContent(outputStream);
+        outputStream.close();
+      }
+    }
+
+    await File(p.join(target, 'version')).writeAsString(version.version);
+    exit(0);
+  }
+
   await _run('curl -L ${version.autoconfUrl} --output sqlite.tar.gz',
       workingDirectory: temporaryDirPath);
   await _run('tar zxvf sqlite.tar.gz', workingDirectory: temporaryDirPath);