import Foundation
import RastrilloNative
import RastrilloTestSupport
import XCTest

final class FaultingBlobStoreTests: XCTestCase {
  func testACrashFreezesTheCommittedViewAndEverythingAfterFails() throws {
    let store = FaultingBlobStore(crashAt: 2)
    try store.write(Data("a".utf8), to: "x/1")
    try store.write(Data("b".utf8), to: "x/2")
    XCTAssertThrowsError(try store.write(Data("c".utf8), to: "x/3")) { XCTAssertEqual($0 as? SimulatedCrash, SimulatedCrash(operation: 2)) }
    XCTAssertThrowsError(try store.read("x/1"), "A dead process does nothing more") { XCTAssertTrue($0 is SimulatedCrash) }
    XCTAssertTrue(store.hasCrashed)
    XCTAssertEqual(store.committed.contents.keys.sorted(), ["x/1", "x/2"], "The crashed write never happened")
    XCTAssertEqual(store.operations, [.write("x/1"), .write("x/2")])
  }

  func testCrashAfterCountsFromNow() throws {
    let store = FaultingBlobStore()
    try store.write(Data("a".utf8), to: "x/1")
    store.crash(after: 1)
    try store.remove("x/1")
    XCTAssertThrowsError(try store.list("x"))
    XCTAssertEqual(store.committed.contents, [:])
  }

  func testUnavailableAnswersEveryOperationAndChangesNothing() throws {
    let store = FaultingBlobStore()
    try store.write(Data("a".utf8), to: "x/1")
    store.unavailable = true
    XCTAssertThrowsError(try store.read("x/1")) { XCTAssertEqual($0 as? BlobStoreError, .unavailable) }
    XCTAssertThrowsError(try store.remove("x/1")) { XCTAssertEqual($0 as? BlobStoreError, .unavailable) }
    XCTAssertThrowsError(try store.list("x")) { XCTAssertEqual($0 as? BlobStoreError, .unavailable) }
    store.unavailable = false
    XCTAssertEqual(try store.read("x/1"), Data("a".utf8))
  }

  func testMemoryStoreListsOneLevelAndRemovesDirectories() throws {
    let store = MemoryBlobStore()
    try store.write(Data(), to: "outbox/1.entry")
    try store.write(Data(), to: "outbox/2.entry")
    try store.write(Data(), to: "cache/docs/a/replica")
    XCTAssertEqual(try store.list("outbox"), ["1.entry", "2.entry"])
    XCTAssertEqual(try store.list("cache/docs"), [])
    try store.remove("cache")
    XCTAssertEqual(store.contents.keys.sorted(), ["outbox/1.entry", "outbox/2.entry"])
  }
}