import Foundation
import SwiftData
import Testing
@testable import Rituals

struct RitualStoreTests {
    @MainActor
    @Test func quickRitualStartsIncomplete() throws {
        let store = makeStore()
        store.createQuickRitual()

        #expect(store.activeRitual != nil)
        #expect(abs(store.activeRitualProgress) < 0.0001)
    }

    @MainActor
    @Test func toggleHabitCompletionMarksComplete() throws {
        let store = makeStore()
        store.createQuickRitual()

        guard let habit = store.activeRitual?.habits.first else {
            throw TestError.missingHabit
        }

        store.toggleHabitCompletion(habit)
        #expect(store.isHabitCompletedToday(habit) == true)
    }

    @MainActor
    @Test func toggleHabitCompletionForSpecificDate() throws {
        let store = makeStore()
        store.createQuickRitual()

        guard let habit = store.activeRitual?.habits.first else {
            throw TestError.missingHabit
        }

        let yesterday = Calendar.current.date(byAdding: .day, value: -1, to: Date())!
        store.toggleHabitCompletion(habit, date: yesterday)
        
        let completions = store.habitCompletions(for: yesterday)
        let completion = completions.first { $0.habit.id == habit.id }
        #expect(completion?.isCompleted == true)
        #expect(store.isHabitCompletedToday(habit) == false)
    }
    
    @MainActor
    @Test func arcRenewalCreatesNewArc() throws {
        let store = makeStore()
        store.createQuickRitual()
        
        guard let ritual = store.activeRitual else {
            throw TestError.missingHabit
        }
        
        #expect((ritual.arcs?.count ?? 0) == 1)
        #expect(ritual.currentArc?.arcNumber == 1)
        
        // End the current arc
        store.endArc(for: ritual)
        
        #expect(ritual.currentArc == nil)
        
        // Renew the arc
        store.renewArc(for: ritual, durationDays: 30, copyHabits: true)
        
        #expect((ritual.arcs?.count ?? 0) == 2)
        #expect(ritual.currentArc?.arcNumber == 2)
        #expect((ritual.currentArc?.habits?.count ?? 0) == 3)
    }

    @MainActor
    @Test func currentStreakCountsOnlyPerfectDays() throws {
        let store = makeStore()
        store.createQuickRitual()

        guard let ritual = store.activeRitual else {
            throw TestError.missingRitual
        }

        let habits = ritual.habits
        guard habits.count >= 2 else {
            throw TestError.missingHabit
        }

        let calendar = Calendar.current
        let today = Date()
        let yesterday = calendar.date(byAdding: .day, value: -1, to: today) ?? today

        // Yesterday is perfect: complete all habits.
        for habit in habits {
            store.toggleHabitCompletion(habit, date: yesterday)
        }

        // Today is partial: complete only one habit.
        store.toggleHabitCompletion(habits[0], date: today)

        #expect(store.currentStreak() == 1)
    }

    @MainActor
    @Test func allRitualCompletionRateIncludesEndedArcsForHistoricalDates() throws {
        let store = makeStore()
        store.createQuickRitual()

        guard let ritual = store.activeRitual,
              let habit = ritual.habits.first,
              let arcStart = ritual.currentArc?.startDate else {
            throw TestError.missingHabit
        }

        store.toggleHabitCompletion(habit, date: arcStart)
        store.endArc(for: ritual)

        let rate = store.completionRate(for: arcStart, ritual: nil)
        #expect(rate > 0.0)
    }

    @MainActor
    @Test func completedActiveArcStillTriggersRenewalPrompt() throws {
        let store = makeStore()
        store.createQuickRitual()

        guard let ritual = store.activeRitual,
              let arc = ritual.currentArc else {
            throw TestError.missingRitual
        }

        let yesterday = Calendar.current.date(byAdding: .day, value: -1, to: Date()) ?? Date()
        arc.endDate = yesterday

        #expect(ritual.hasActiveArc == false)

        store.checkForCompletedArcs()
        #expect(store.ritualNeedingRenewal?.id == ritual.id)
    }

    @MainActor
    @Test func currentArcUsesMostRecentActiveArc() throws {
        let calendar = Calendar.current
        let today = calendar.startOfDay(for: Date())
        let oldStart = calendar.date(byAdding: .day, value: -20, to: today) ?? today
        let oldEnd = calendar.date(byAdding: .day, value: -5, to: today) ?? today
        let currentStart = calendar.date(byAdding: .day, value: -2, to: today) ?? today
        let currentEnd = calendar.date(byAdding: .day, value: 10, to: today) ?? today

        let oldArc = RitualArc(startDate: oldStart, endDate: oldEnd, arcNumber: 1, isActive: true)
        let currentArc = RitualArc(startDate: currentStart, endDate: currentEnd, arcNumber: 2, isActive: true)
        let ritual = Ritual(title: "Test", theme: "Theme", arcs: [oldArc, currentArc])

        #expect(ritual.currentArc?.arcNumber == 2)
        #expect(ritual.hasActiveArc == true)
    }

    @MainActor
    @Test func completedArcCountIncludesExpiredActiveArcs() throws {
        let calendar = Calendar.current
        let today = calendar.startOfDay(for: Date())
        let start = calendar.date(byAdding: .day, value: -10, to: today) ?? today
        let end = calendar.date(byAdding: .day, value: -1, to: today) ?? today

        let expiredButActiveArc = RitualArc(startDate: start, endDate: end, arcNumber: 1, isActive: true)
        let ritual = Ritual(title: "Expired", theme: "Theme", arcs: [expiredButActiveArc])

        #expect(ritual.completedArcCount == 1)
        #expect(Calendar.current.isDate(ritual.lastCompletedDate ?? .distantPast, inSameDayAs: end))
    }

    @MainActor
    @Test func nextUpcomingRitualContextIdentifiesTomorrowForFutureArc() throws {
        let calendar = Calendar.current
        let today = calendar.startOfDay(for: Date())
        let tomorrow = calendar.date(byAdding: .day, value: 1, to: today) ?? today
        let nextWeek = calendar.date(byAdding: .day, value: 7, to: tomorrow) ?? tomorrow
        let middayToday = calendar.date(byAdding: .hour, value: 12, to: today) ?? today

        let tomorrowArc = RitualArc(startDate: tomorrow, endDate: nextWeek, arcNumber: 1, isActive: true)
        let eveningRitual = Ritual(
            title: "Evening Wind Down",
            theme: "Test",
            timeOfDay: .evening,
            arcs: [tomorrowArc]
        )

        let context = RitualAnalytics.nextUpcomingRitualContext(from: [eveningRitual], currentDate: middayToday)
        #expect(context?.ritual.id == eveningRitual.id)
        #expect(context?.isTomorrow == true)
    }
}

@MainActor
private func makeStore() -> RitualStore {
    let schema = Schema([Ritual.self, RitualArc.self, ArcHabit.self])
    let configuration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true)
    let container: ModelContainer
    do {
        container = try ModelContainer(for: schema, configurations: [configuration])
    } catch {
        fatalError("Test container failed: \(error)")
    }

    return RitualStore(modelContext: container.mainContext, seedService: EmptySeedService(), settingsStore: SettingsStore())
}

private struct EmptySeedService: RitualSeedProviding {
    func makeSeedRituals(startDate: Date) -> [Ritual] {
        []
    }
}

private enum TestError: Error {
    case missingHabit
    case missingRitual
}