//
//  MigrationTests.swift
//  KeymanEngineTests
//
//  Created by Joshua Horton on 2/20/20.
//  Copyright © 2020 SIL International. All rights reserved.
//

import Foundation
@testable import KeymanEngine
import XCTest

class MigrationTests: XCTestCase {
  override func tearDown() {
    TestUtils.standardTearDown()
  }

  func testVersion12ResourceMigration() {
    TestUtils.Migrations.applyBundleToFileSystem(TestUtils.Migrations.simple_12)

    let userDefaults = Storage.active.userDefaults
    userDefaults.lastEngineVersion = Version("12.0")!

    let versionResources = TestUtils.Migrations.getVersionHistory(for: Version("12.0")!)
    TestUtils.UserDefaults.addKeyboard(versionResources[0] as! InstallableKeyboard)
    TestUtils.UserDefaults.addKeyboard(TestUtils.Keyboards.khmer_angkor)
    TestUtils.UserDefaults.addLexicalModel(versionResources[1] as! InstallableLexicalModel)

    Migrations.updateResources(storage: Storage.active)

    // The two keyboards should remain in the same location, while the lexical model should be upgraded.
    // v 0.1.2 -> 0.1.4.
    // Minor surprise (as of 13.0) is that 0.1.2's file actually remains!

    let defaultModel = userDefaults.userLexicalModels![0]
    XCTAssertEqual(defaultModel.id, Defaults.lexicalModel.id)
    XCTAssertEqual(defaultModel.version, Defaults.lexicalModel.version)
    let modelURL = Storage.active.lexicalModelURL(for: TestUtils.LexicalModels.mtnt) // The bundled, 0.1.4 version.
    XCTAssert(FileManager.default.fileExists(atPath: modelURL.path))
  }

  func testVersion12AdhocMigration() throws {
    TestUtils.Migrations.applyBundleToFileSystem(TestUtils.Migrations.adhoc_12)

    let userDefaults = Storage.active.userDefaults
    userDefaults.lastEngineVersion = Version("12.0")!
    TestUtils.UserDefaults.addKeyboard(TestUtils.Keyboards.khmer10)

    Migrations.migrate(storage: Storage.active)

    // The files in the .documents directory should be erased after this method is run.

    let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
    let documentsContents = try FileManager.default.contentsOfDirectory(atPath: documentsDirectory.path)
    XCTAssertEqual(documentsContents.count, 1, "Documents directory was not purged of installation by-products during ad-hoc resource migration!")

    // The .kmp.zip is converted back into its original .kmp file, which remains in the Documents directory
    // so that it may be used for sharing.
    let kmpURL = URL(fileURLWithPath: documentsContents[0])
    XCTAssertEqual(kmpURL.lastPathComponent, "khmer10.kmp")
  }

  func testVersion10ResourceMigration() {
    TestUtils.Migrations.applyBundleToFileSystem(TestUtils.Migrations.simple_10)

    let userDefaults = Storage.active.userDefaults
    TestUtils.UserDefaults.addKeyboard(TestUtils.Migrations.european2)

    Migrations.updateResources(storage: Storage.active)

    // The old keyboard should be gone entirely, replaced by the current version's default resources.
    // There should only be one default resource per type (at least, as of 13.0.)
    XCTAssertEqual(userDefaults.userKeyboards!.count, 1, "Unexpected keyboard count after migration!")
    // 3, b/c all language-code variants are counted.
    XCTAssertEqual(userDefaults.userLexicalModels!.count, 3, "Unexpected lexical model count after migration!")

    let defaultKeyboard = userDefaults.userKeyboards![0]
    XCTAssertNotEqual(TestUtils.Migrations.european2.id, defaultKeyboard.id) // Double-ensure that the ID is new.
    XCTAssertEqual(defaultKeyboard.id, Defaults.keyboard.id)
    XCTAssertEqual(defaultKeyboard.version, Defaults.keyboard.version)

    let defaultModel = userDefaults.userLexicalModels![0]
    XCTAssertEqual(defaultModel.id, Defaults.lexicalModel.id)
    XCTAssertEqual(defaultModel.version, Defaults.lexicalModel.version)

    let keyboardURL = Storage.active.keyboardURL(for: Defaults.keyboard)
    let modelURL = Storage.active.lexicalModelURL(for: Defaults.lexicalModel)
    XCTAssert(FileManager.default.fileExists(atPath: keyboardURL.path))
    XCTAssert(FileManager.default.fileExists(atPath: modelURL.path))
  }

  func testNoDefaultVersion10ResourceMigration() {
    TestUtils.Migrations.applyBundleToFileSystem(TestUtils.Migrations.noDefault_10)

    let userDefaults = Storage.active.userDefaults
    TestUtils.UserDefaults.addKeyboard(TestUtils.Keyboards.khmer_angkor)

    Migrations.updateResources(storage: Storage.active)

    // No new resources should be installed - only what was originally present should be there.
    XCTAssertEqual(userDefaults.userKeyboards!.count, 1, "Unexpected keyboard count after migration!")
    // There was no prior lexical model installed, so the installation still proceeds.  The user just won't see it.
    XCTAssertNil(userDefaults.userLexicalModels, "Unexpected lexical model(s) installed after migration!")

    let keyboard = userDefaults.userKeyboards![0]
    XCTAssertEqual(keyboard.id, TestUtils.Keyboards.khmer_angkor.id, "Unexpected keyboard was installed after migration!")
    XCTAssertEqual(keyboard.version, TestUtils.Keyboards.khmer_angkor.version)

    // If successful, confirms that the current default resources are not installed - as expected.
  }
}