// Tests/SwiftProtobufPluginLibraryTests/Test_Descriptor.swift - Test Descriptor.swift
//
// Copyright (c) 2014 - 2024 Apple Inc. and the project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See LICENSE.txt for license information:
// https://github.com/apple/swift-protobuf/blob/main/LICENSE.txt
//
// -----------------------------------------------------------------------------

import SwiftProtobuf
import SwiftProtobufPluginLibrary
import XCTest

final class Test_FeatureResolver: XCTestCase {

    private func simpleResolver(extensions: [any AnyMessageExtension] = []) -> FeatureResolver {
        let defaults = try! Google_Protobuf_FeatureSetDefaults(
            textFormatString: """
                minimum_edition: EDITION_PROTO2
                maximum_edition: EDITION_2023
                defaults { edition: EDITION_2023 }
                """
        )
        return try! FeatureResolver(
            edition: .edition2023,
            featureSetDefaults: defaults,
            featureExtensions: extensions
        )
    }

    func testInit_EditionBelowMin() {
        let defaults = Google_Protobuf_FeatureSetDefaults.with {
            $0.minimumEdition = .proto3
            $0.maximumEdition = .edition2023
        }
        XCTAssertThrowsError(try FeatureResolver(edition: .proto2, featureSetDefaults: defaults)) { e in
            XCTAssertEqual(
                e as! FeatureResolver.Error,
                FeatureResolver.Error.unsupported(
                    edition: .proto2,
                    supported: Google_Protobuf_Edition.proto3...Google_Protobuf_Edition.edition2023
                )
            )
        }
    }

    func testInit_EditionAboveMax() {
        let defaults = Google_Protobuf_FeatureSetDefaults.with {
            $0.minimumEdition = .proto2
            $0.maximumEdition = .proto3
        }
        XCTAssertThrowsError(try FeatureResolver(edition: .edition2023, featureSetDefaults: defaults)) { e in
            XCTAssertEqual(
                e as! FeatureResolver.Error,
                FeatureResolver.Error.unsupported(
                    edition: .edition2023,
                    supported: Google_Protobuf_Edition.proto2...Google_Protobuf_Edition.proto3
                )
            )
        }
    }

    func testInit_EditionDefaultNotFound() {
        let defaults = try! Google_Protobuf_FeatureSetDefaults(
            textFormatString: """
                minimum_edition: EDITION_PROTO2
                maximum_edition: EDITION_2023
                defaults { edition: EDITION_2023 }
                """
        )
        XCTAssertThrowsError(try FeatureResolver(edition: .proto2, featureSetDefaults: defaults)) { e in
            XCTAssertEqual(
                e as! FeatureResolver.Error,
                FeatureResolver.Error.noDefault(edition: .proto2)
            )
        }
    }

    func testInit_EditionExactMatches() throws {
        let defaults = try! Google_Protobuf_FeatureSetDefaults(
            textFormatString: """
                minimum_edition: EDITION_99997_TEST_ONLY
                maximum_edition: EDITION_99999_TEST_ONLY
                defaults {
                    edition: EDITION_99997_TEST_ONLY
                    overridable_features { field_presence: EXPLICIT}
                }
                defaults {
                    edition: EDITION_99998_TEST_ONLY
                    overridable_features { field_presence: IMPLICIT}
                }
                defaults {
                    edition: EDITION_99999_TEST_ONLY
                    overridable_features { field_presence: LEGACY_REQUIRED}
                }
                """
        )

        // Ensure the right things were matched and we got the right feature sets.

        // If lookup fails, throw out of the test method.

        // edition99997TestOnly
        let resolver1: FeatureResolver = try FeatureResolver(
            edition: .edition99997TestOnly,
            featureSetDefaults: defaults
        )
        XCTAssertEqual(resolver1.edition, .edition99997TestOnly)
        XCTAssertEqual(resolver1.defaultFeatureSet.fieldPresence, .explicit)

        // edition99998TestOnly
        let resolver2 = try FeatureResolver(
            edition: .edition99998TestOnly,
            featureSetDefaults: defaults
        )
        XCTAssertEqual(resolver2.edition, .edition99998TestOnly)
        XCTAssertEqual(resolver2.defaultFeatureSet.fieldPresence, .implicit)

        // edition99999TestOnly
        let resolver3 = try FeatureResolver(
            edition: .edition99999TestOnly,
            featureSetDefaults: defaults
        )
        XCTAssertEqual(resolver3.edition, .edition99999TestOnly)
        XCTAssertEqual(resolver3.defaultFeatureSet.fieldPresence, .legacyRequired)
    }

    func testInit_EditionMatchesLower() throws {
        let defaults = try! Google_Protobuf_FeatureSetDefaults(
            textFormatString: """
                minimum_edition: EDITION_99997_TEST_ONLY
                maximum_edition: EDITION_99999_TEST_ONLY
                defaults {
                    edition: EDITION_99997_TEST_ONLY
                    overridable_features { field_presence: EXPLICIT}
                }
                defaults {
                    edition: EDITION_99999_TEST_ONLY
                    overridable_features { field_presence: LEGACY_REQUIRED}
                }
                """
        )

        // Ensure the right things were matched and we got the right feature sets.

        // If lookup fails, throw out of the test method.

        // edition99997TestOnly
        let resolver1: FeatureResolver = try FeatureResolver(
            edition: .edition99997TestOnly,
            featureSetDefaults: defaults
        )
        XCTAssertEqual(resolver1.edition, .edition99997TestOnly)
        XCTAssertEqual(resolver1.defaultFeatureSet.fieldPresence, .explicit)

        // edition99998TestOnly
        // The edition will says 99998 since that's what we requested, but the
        // defaults will have what was in 99997
        let resolver2 = try FeatureResolver(
            edition: .edition99998TestOnly,
            featureSetDefaults: defaults
        )
        XCTAssertEqual(resolver2.edition, .edition99998TestOnly)
        XCTAssertEqual(resolver2.defaultFeatureSet.fieldPresence, .explicit)

        // edition99999TestOnly
        let resolver3 = try FeatureResolver(
            edition: .edition99999TestOnly,
            featureSetDefaults: defaults
        )
        XCTAssertEqual(resolver3.edition, .edition99999TestOnly)
        XCTAssertEqual(resolver3.defaultFeatureSet.fieldPresence, .legacyRequired)
    }

    func testInit_BadExtension() throws {
        let defaults = try! Google_Protobuf_FeatureSetDefaults(
            textFormatString: """
                minimum_edition: EDITION_PROTO2
                maximum_edition: EDITION_2023
                defaults { edition: EDITION_PROTO2 }
                """
        )

        XCTAssertThrowsError(
            try FeatureResolver(
                edition: .proto2,
                featureSetDefaults: defaults,
                featureExtensions: [
                    SwiftFeatureTest_Extensions_test,
                    SDTExtensions_ext_str,
                ]
            )
        ) { e in
            XCTAssertEqual(
                e as! FeatureResolver.Error,
                FeatureResolver.Error.invalidExtension(type: "swift_descriptor_test.import.ExtendableOne")
            )
        }
    }

    func testInit_mergingFixedOverridable() throws {
        let defaults = try! Google_Protobuf_FeatureSetDefaults(
            textFormatString: """
                minimum_edition: EDITION_99997_TEST_ONLY
                maximum_edition: EDITION_99999_TEST_ONLY
                defaults {
                    edition: EDITION_99997_TEST_ONLY
                    overridable_features { field_presence: EXPLICIT }
                    fixed_features { enum_type: CLOSED }
                }
                """
        )

        // Test that fixed and overridable merge

        // If lookup fails, throw out of the test method.

        let resolver1: FeatureResolver = try FeatureResolver(
            edition: .edition99997TestOnly,
            featureSetDefaults: defaults
        )
        XCTAssertEqual(resolver1.edition, .edition99997TestOnly)
        XCTAssertEqual(resolver1.defaultFeatureSet.fieldPresence, .explicit)
        XCTAssertEqual(resolver1.defaultFeatureSet.enumType, .closed)
    }

    func testResolve_Basics() {
        let resolver = simpleResolver()

        let features1 = Google_Protobuf_FeatureSet.with {
            $0.fieldPresence = .explicit
            $0.messageEncoding = .lengthPrefixed
        }
        let features2 = Google_Protobuf_FeatureSet.with {
            $0.enumType = .open
        }
        let features3 = Google_Protobuf_FeatureSet.with {
            $0.fieldPresence = .legacyRequired
            $0.jsonFormat = .legacyBestEffort
        }

        // No overlap
        let merged12 = resolver.resolve(features: features1, resolvedParent: features2)
        XCTAssertEqual(merged12.fieldPresence, .explicit)
        XCTAssertEqual(merged12.enumType, .open)
        XCTAssertEqual(merged12.messageEncoding, .lengthPrefixed)

        // Overlap, features overrides parent features
        let merged13 = resolver.resolve(features: features1, resolvedParent: features3)
        XCTAssertEqual(merged13.fieldPresence, .explicit)
        XCTAssertEqual(merged13.jsonFormat, .legacyBestEffort)
        XCTAssertEqual(merged13.messageEncoding, .lengthPrefixed)
    }

    func testResolve_CustomFeature() {
        let resolver = simpleResolver(extensions: [SwiftFeatureTest_Extensions_test])

        let features1 = Google_Protobuf_FeatureSet.with {
            $0.SwiftFeatureTest_test.feature1 = .value2
            $0.SwiftFeatureTest_test.feature2 = .value2
        }
        let features2 = Google_Protobuf_FeatureSet.with {
            $0.SwiftFeatureTest_test.feature3 = .value3
        }
        let features3 = Google_Protobuf_FeatureSet.with {
            $0.SwiftFeatureTest_test.feature1 = .value4
            $0.SwiftFeatureTest_test.feature3 = .value4
        }

        // No overlap
        let merged12 = resolver.resolve(features: features1, resolvedParent: features2)
        XCTAssertEqual(merged12.SwiftFeatureTest_test.feature1, .value2)
        XCTAssertEqual(merged12.SwiftFeatureTest_test.feature2, .value2)
        XCTAssertEqual(merged12.SwiftFeatureTest_test.feature3, .value3)

        // Overlap, features overrides parent features
        let merged13 = resolver.resolve(features: features1, resolvedParent: features3)
        XCTAssertEqual(merged13.SwiftFeatureTest_test.feature1, .value2)
        XCTAssertEqual(merged13.SwiftFeatureTest_test.feature2, .value2)
        XCTAssertEqual(merged13.SwiftFeatureTest_test.feature3, .value4)
    }
}