import Foundation
import RastrilloNative
import XCTest

private func summary(_ lanes: [String: (pending: Int, held: Int, inFlight: Int)], hold: Hold.Reason? = nil) -> OutboxSummary {
  var summary = OutboxSummary()
  for (name, counts) in lanes {
    var lane = OutboxSummary.Lane()
    lane.pending = counts.pending; lane.held = counts.held; lane.inFlight = counts.inFlight
    if counts.held > 0 { lane.firstHold = hold ?? .accessLost }
    summary.lanes[name] = lane
  }
  return summary
}

final class SyncStatusTests: XCTestCase {
  func testPriorityOrder() {
    let pending = summary(["doc:a": (2, 0, 0), "doc:b": (1, 0, 0)])
    let held = summary(["doc:a": (1, 1, 0)], hold: .tooLarge)
    let flying = summary(["doc:a": (2, 0, 1)])

    // 1. A hold beats everything, even an ended session.
    XCTAssertEqual(SyncStatus(summary: held, sending: true, sessionEnded: true, offline: true, backingOff: true),
                   .failed(pending: 1, reason: .held(.tooLarge)))
    // A local failure is failed too.
    XCTAssertEqual(SyncStatus(summary: pending, sending: false, sessionEnded: false, offline: false, backingOff: false, localFailure: .cannotSaveOnDevice),
                   .failed(pending: 2, reason: .cannotSaveOnDevice))
    // 2. Session ended.
    XCTAssertEqual(SyncStatus(summary: pending, sending: false, sessionEnded: true, offline: true, backingOff: true), .needsSignIn(pending: 2))
    // 3. Nothing to send.
    XCTAssertEqual(SyncStatus(summary: OutboxSummary(), sending: false, sessionEnded: false, offline: false, backingOff: false), .saved)
    // 4. In flight.
    XCTAssertEqual(SyncStatus(summary: flying, sending: true, sessionEnded: false, offline: true, backingOff: false), .saving)
    // 5. Offline.
    XCTAssertEqual(SyncStatus(summary: pending, sending: false, sessionEnded: false, offline: true, backingOff: true), .offline(pending: 2))
    // 6. Backing off.
    XCTAssertEqual(SyncStatus(summary: pending, sending: false, sessionEnded: false, offline: false, backingOff: true), .retrying(pending: 2))
    // Sendable, online, not yet started: about to save, never "saved".
    XCTAssertEqual(SyncStatus(summary: pending, sending: false, sessionEnded: false, offline: false, backingOff: false), .saving)
  }

  func testOfflineWithNothingPendingIsSilentlySaved() {
    let status = SyncStatus(summary: OutboxSummary(), sending: false, sessionEnded: false, offline: true, backingOff: false)
    XCTAssertEqual(status, .saved, "\"Offline · 0 pending\" must never appear")
    XCTAssertEqual(SyncStatus(summary: OutboxSummary(), sending: false, sessionEnded: true, offline: true, backingOff: false), .needsSignIn(pending: 0),
                   "Session-ended has priority over an empty outbox (spec 3.4)")
  }

  func testNCountsLanesByDefaultAndWhatTheAppChooses() {
    let lanes = summary(["doc:a": (5, 0, 0), "doc:b": (1, 0, 0)])
    XCTAssertEqual(SyncStatus(summary: lanes, sending: false, sessionEnded: false, offline: true, backingOff: false), .offline(pending: 2))
    XCTAssertEqual(SyncStatus(summary: lanes, sending: false, sessionEnded: false, offline: true, backingOff: false, count: { $0.pending }),
                   .offline(pending: 6))
  }

  func testSaveStateMappingStickinessAndAnnouncements() {
    XCTAssertEqual(SyncStatus.saved.saveState, .saved)
    XCTAssertEqual(SyncStatus.saving.saveState, .saving)
    XCTAssertEqual(SyncStatus.offline(pending: 1).saveState, .retrying, "The Slides precedent: offline is retrying")
    XCTAssertEqual(SyncStatus.retrying(pending: 1).saveState, .retrying)
    XCTAssertEqual(SyncStatus.needsSignIn(pending: 1).saveState, .failed)
    XCTAssertEqual(SyncStatus.failed(pending: 1, reason: .tooManyUnsent).saveState, .failed)
    XCTAssertTrue(SyncStatus.needsSignIn(pending: 1).isSticky)
    XCTAssertTrue(SyncStatus.failed(pending: 1, reason: .cannotSaveOnDevice).isSticky)
    XCTAssertFalse(SyncStatus.offline(pending: 1).isSticky)
    XCTAssertFalse(SyncStatus.saving.isAnnounced, "A saving flicker is never announced")
    XCTAssertTrue(SyncStatus.offline(pending: 1).isAnnounced)
    XCTAssertTrue(SyncStatus.needsSignIn(pending: 1).isAnnounced)
    XCTAssertTrue(SyncStatus.failed(pending: 1, reason: .tooManyUnsent).isAnnounced)
  }
}