import XCTest
@testable import PortfolioJournal

/// The watch payload travels between processes and devices, so its encoding and
/// the formatting the complications rely on are worth pinning down.
final class WatchPortfolioSnapshotTests: XCTestCase {

    private func makeSnapshot(
        goals: [WatchPortfolioSnapshot.Goal] = [],
        totalValue: Double = 1_000
    ) -> WatchPortfolioSnapshot {
        WatchPortfolioSnapshot(
            generatedAt: Date(timeIntervalSince1970: 1_770_000_000),
            currencyCode: "EUR",
            totalValue: totalValue,
            monthChange: 250,
            monthChangePercent: 0.025,
            sources: [],
            goals: goals,
            currentStreak: 3,
            bestStreak: 9,
            checkInDone: true,
            checkInMonthLabel: "August 2026"
        )
    }

    private func makeGoal(name: String, current: Double, target: Double) -> WatchPortfolioSnapshot.Goal {
        WatchPortfolioSnapshot.Goal(
            id: UUID(),
            name: name,
            categoryName: "Cash",
            categoryIcon: "banknote.fill",
            categoryColorHex: "#6B7280",
            currentValue: current,
            targetValue: target
        )
    }

    // MARK: - Transport

    func testApplicationContextRoundTrip() throws {
        let snapshot = makeSnapshot(goals: [makeGoal(name: "Cash", current: 40_000, target: 100_000)])

        let context = try XCTUnwrap(snapshot.applicationContext())
        let decoded = try XCTUnwrap(WatchPortfolioSnapshot.from(applicationContext: context))

        XCTAssertEqual(decoded, snapshot)
    }

    func testApplicationContextIgnoresUnrelatedPayload() {
        XCTAssertNil(WatchPortfolioSnapshot.from(applicationContext: ["somethingElse": 1]))
    }

    func testEmptySnapshotReportsNoData() {
        XCTAssertFalse(WatchPortfolioSnapshot.empty.hasData)
        XCTAssertTrue(makeSnapshot().hasData)
    }

    // MARK: - Goals

    func testProgressIsClampedBetweenZeroAndOne() {
        XCTAssertEqual(makeGoal(name: "Over", current: 150, target: 100).progress, 1)
        XCTAssertEqual(makeGoal(name: "Negative", current: -50, target: 100).progress, 0)
        XCTAssertEqual(makeGoal(name: "Half", current: 50, target: 100).progress, 0.5)
    }

    func testProgressWithoutTargetIsZero() {
        XCTAssertEqual(makeGoal(name: "No target", current: 50, target: 0).progress, 0)
    }

    /// The single-goal complication must skip goals already reached.
    func testFeaturedGoalSkipsAchievedGoals() {
        let achieved = makeGoal(name: "Done", current: 100, target: 100)
        let open = makeGoal(name: "Cash buffer", current: 40, target: 100)
        let snapshot = makeSnapshot(goals: [achieved, open])

        XCTAssertEqual(snapshot.featuredGoal?.name, "Cash buffer")
    }

    func testFeaturedGoalFallsBackToFirstWhenAllAchieved() {
        let first = makeGoal(name: "First", current: 100, target: 100)
        let second = makeGoal(name: "Second", current: 200, target: 200)

        XCTAssertEqual(makeSnapshot(goals: [first, second]).featuredGoal?.name, "First")
    }

    func testFeaturedGoalIsNilWithoutGoals() {
        XCTAssertNil(makeSnapshot().featuredGoal)
    }

    // MARK: - Formatting

    func testCompactFormatShortensLargeAmounts() {
        func compact(_ value: Double) -> String {
            WatchPortfolioSnapshot.format(value, currencyCode: "EUR", compact: true)
        }

        XCTAssertTrue(compact(750).contains("750"))
        XCTAssertTrue(compact(1_500).contains("1.5K"))
        XCTAssertTrue(compact(25_000).contains("25K"))
        XCTAssertTrue(compact(2_000_000).contains("2.0M"))
        XCTAssertTrue(compact(-1_500).hasPrefix("-"))
    }

    func testMonthChangeCarriesExplicitSign() {
        let positive = makeSnapshot()
        XCTAssertTrue(positive.formattedMonthChange().hasPrefix("+"))
        XCTAssertEqual(positive.formattedMonthChangePercent, "+2.5%")

        let negative = WatchPortfolioSnapshot(
            generatedAt: Date(),
            currencyCode: "EUR",
            totalValue: 1_000,
            monthChange: -250,
            monthChangePercent: -0.025,
            sources: [],
            goals: [],
            currentStreak: 0,
            bestStreak: 0,
            checkInDone: false,
            checkInMonthLabel: ""
        )
        XCTAssertTrue(negative.formattedMonthChange().hasPrefix("-"))
        XCTAssertEqual(negative.formattedMonthChangePercent, "-2.5%")
    }
}