// ── Cascade Tests ──────────────────────────────────────────────
// XCTest unit tests mirroring web cascade.test.ts

import XCTest
@testable import ChronoMind

final class CascadeTests: XCTestCase {

    // MARK: - Preset Intervals

    func testAggressivePreset() {
        let intervals = CascadePreset.aggressive.defaultIntervals
        XCTAssertEqual(intervals, [240, 180, 120, 90, 60, 30, 15, 5, 1])
    }

    func testStandardPreset() {
        let intervals = CascadePreset.standard.defaultIntervals
        XCTAssertEqual(intervals, [120, 60, 30, 15, 5])
    }

    func testLightPreset() {
        let intervals = CascadePreset.light.defaultIntervals
        XCTAssertEqual(intervals, [60, 15, 5])
    }

    func testMinimalPreset() {
        let intervals = CascadePreset.minimal.defaultIntervals
        XCTAssertEqual(intervals, [15])
    }

    func testNonePreset() {
        let intervals = CascadePreset.none.defaultIntervals
        XCTAssertTrue(intervals.isEmpty)
    }

    // MARK: - Calculate Cascade Warnings

    func testCalculateWarnings() {
        let now = Date()
        let targetTime = now.addingTimeInterval(3600) // 1h from now
        let intervals = [60, 30, 15, 5]

        let warnings = calculateCascadeWarnings(targetTime: targetTime, intervals: intervals, now: now)

        XCTAssertEqual(warnings.count, 4)
        // Should be sorted largest first
        XCTAssertEqual(warnings[0].minutesBefore, 60)
        XCTAssertEqual(warnings[1].minutesBefore, 30)
        XCTAssertEqual(warnings[2].minutesBefore, 15)
        XCTAssertEqual(warnings[3].minutesBefore, 5)
    }

    func testWarningsInPastAreFired() {
        let now = Date()
        let targetTime = now.addingTimeInterval(1800) // 30 min from now
        let intervals = [120, 60, 15, 5] // 2h and 1h are in the past

        let warnings = calculateCascadeWarnings(targetTime: targetTime, intervals: intervals, now: now)

        // 120min and 60min warnings should be marked as fired (they're in the past)
        let fired = warnings.filter(\.fired)
        XCTAssertEqual(fired.count, 2)
        XCTAssertTrue(warnings[0].fired) // 120m — in the past
        XCTAssertTrue(warnings[1].fired) // 60m — in the past
        XCTAssertFalse(warnings[2].fired) // 15m — still in the future
        XCTAssertFalse(warnings[3].fired) // 5m — still in the future
    }

    func testWarningScheduledTimes() {
        let now = Date()
        let targetTime = now.addingTimeInterval(7200) // 2h from now
        let intervals = [60, 30]

        let warnings = calculateCascadeWarnings(targetTime: targetTime, intervals: intervals, now: now)

        // 60min warning should be at targetTime - 60min
        let expected60 = targetTime.addingTimeInterval(-3600)
        XCTAssertEqual(warnings[0].scheduledTime.timeIntervalSince1970,
                       expected60.timeIntervalSince1970, accuracy: 1.0)

        // 30min warning should be at targetTime - 30min
        let expected30 = targetTime.addingTimeInterval(-1800)
        XCTAssertEqual(warnings[1].scheduledTime.timeIntervalSince1970,
                       expected30.timeIntervalSince1970, accuracy: 1.0)
    }

    func testEmptyIntervals() {
        let now = Date()
        let targetTime = now.addingTimeInterval(3600)
        let warnings = calculateCascadeWarnings(targetTime: targetTime, intervals: [], now: now)

        XCTAssertTrue(warnings.isEmpty)
    }

    // MARK: - Get Next Warning

    func testGetNextWarning() {
        let now = Date()
        let targetTime = now.addingTimeInterval(7200) // 2h from now
        let warnings = calculateCascadeWarnings(
            targetTime: targetTime,
            intervals: [60, 30, 15, 5],
            now: now
        )

        let next = getNextWarning(warnings)
        XCTAssertNotNil(next)
        // All warnings are in the future (earliest at targetTime - 60m = 1h from now)
        XCTAssertEqual(next?.minutesBefore, 60)
    }

    func testGetNextWarningAllFired() {
        let now = Date()
        let targetTime = now.addingTimeInterval(60) // 1 min from now
        var warnings = calculateCascadeWarnings(
            targetTime: targetTime,
            intervals: [120, 60, 30],
            now: now
        )
        // Mark all as fired
        for i in warnings.indices { warnings[i].fired = true }

        let next = getNextWarning(warnings)
        XCTAssertNil(next)
    }

    // MARK: - Check Warnings

    func testCheckWarnings() {
        let now = Date()
        let targetTime = now.addingTimeInterval(7200) // 2h from now
        var warnings = calculateCascadeWarnings(
            targetTime: targetTime,
            intervals: [60, 30, 15, 5],
            now: now
        )

        // All warnings should be unfired initially
        XCTAssertTrue(warnings.allSatisfy { !$0.fired })

        // Check at a time when 60m warning should fire (targetTime - 60min)
        let checkTime = targetTime.addingTimeInterval(-3599) // 1 second after 60m mark
        let fired = checkWarnings(&warnings, now: checkTime)

        // The 60m warning should fire
        XCTAssertEqual(fired.count, 1)
        XCTAssertTrue(warnings[0].fired) // 60m warning fired
        XCTAssertFalse(warnings[1].fired) // 30m warning not yet
    }

    func testCheckWarningsNoneFire() {
        let now = Date()
        let targetTime = now.addingTimeInterval(7200) // 2h from now
        var warnings = calculateCascadeWarnings(
            targetTime: targetTime,
            intervals: [60, 30, 15],
            now: now
        )

        // Check at current time — no warnings should fire yet (earliest is in 1h)
        let fired = checkWarnings(&warnings, now: now)
        XCTAssertTrue(fired.isEmpty)
    }

    // MARK: - Get Cascade Intervals

    func testGetCascadeIntervalsPreset() {
        let config = CascadeConfig(preset: .standard, intervals: [])
        let intervals = getCascadeIntervals(config)
        XCTAssertEqual(intervals, [120, 60, 30, 15, 5])
    }

    func testGetCascadeIntervalsCustom() {
        let config = CascadeConfig(preset: .custom, intervals: [10, 45, 5, 30])
        let intervals = getCascadeIntervals(config)
        XCTAssertEqual(intervals, [45, 30, 10, 5]) // sorted descending
    }

    // MARK: - Format Minutes Before

    func testFormatMinutesBefore() {
        XCTAssertEqual(formatMinutesBefore(5), "5m")
        XCTAssertEqual(formatMinutesBefore(15), "15m")
        XCTAssertEqual(formatMinutesBefore(60), "1h")
        XCTAssertEqual(formatMinutesBefore(90), "1h 30m")
        XCTAssertEqual(formatMinutesBefore(120), "2h")
        XCTAssertEqual(formatMinutesBefore(240), "4h")
    }
}