//
//  ItinerarySectionBuilderTests.swift
//  SportsTimeTests
//
//  Tests for ItinerarySectionBuilder pure static function.
//

import Testing
import CoreLocation
@testable import SportsTime

@Suite("ItinerarySectionBuilder")
struct ItinerarySectionBuilderTests {

    // MARK: - Helpers

    private func makeTripDays(count: Int, startDate: Date = TestClock.now) -> [Date] {
        (0..<count).map {
            TestClock.calendar.date(byAdding: .day, value: $0, to: TestClock.calendar.startOfDay(for: startDate))!
        }
    }

    private func makeTrip(
        cities: [String] = ["New York", "Boston"],
        startDate: Date = TestClock.now,
        daysPerStop: Int = 1,
        gameIds: [[String]] = []
    ) -> (Trip, [Date]) {
        let stops = TestFixtures.tripStops(cities: cities, startDate: startDate, daysPerStop: daysPerStop)
        var stopsWithGames = stops
        for (i, ids) in gameIds.enumerated() where i < stopsWithGames.count {
            stopsWithGames[i] = TripStop(
                stopNumber: stopsWithGames[i].stopNumber,
                city: stopsWithGames[i].city,
                state: stopsWithGames[i].state,
                coordinate: stopsWithGames[i].coordinate,
                arrivalDate: stopsWithGames[i].arrivalDate,
                departureDate: stopsWithGames[i].departureDate,
                games: ids,
                isRestDay: stopsWithGames[i].isRestDay
            )
        }
        let trip = TestFixtures.trip(stops: stopsWithGames)
        let totalDays = cities.count * daysPerStop
        let days = makeTripDays(count: totalDays, startDate: startDate)
        return (trip, days)
    }

    // MARK: - Tests

    @Test("builds one section per day")
    func buildsSectionsForEachDay() {
        let startDate = TestClock.calendar.startOfDay(for: TestClock.now)
        let (trip, days) = makeTrip(cities: ["New York", "Boston", "Philadelphia"], startDate: startDate)

        let sections = ItinerarySectionBuilder.build(
            trip: trip,
            tripDays: days,
            games: [:],
            travelOverrides: [:],
            itineraryItems: [],
            allowCustomItems: false
        )

        // Should have travel + day sections
        let daySections = sections.filter {
            if case .day = $0 { return true }
            return false
        }
        #expect(daySections.count == days.count)
    }

    @Test("games filtered correctly by date")
    func gamesOnFiltersCorrectly() {
        let startDate = TestClock.calendar.startOfDay(for: TestClock.now)
        let gameDate = startDate
        let game = TestFixtures.game(sport: .mlb, city: "New York", dateTime: gameDate)
        let richGame = TestFixtures.richGame(game: game, homeCity: "New York")

        let (trip, days) = makeTrip(
            cities: ["New York", "Boston"],
            startDate: startDate,
            gameIds: [[game.id]]
        )

        let sections = ItinerarySectionBuilder.build(
            trip: trip,
            tripDays: days,
            games: [game.id: richGame],
            travelOverrides: [:],
            itineraryItems: [],
            allowCustomItems: false
        )

        // Find the first day section and verify it has a game
        let firstDaySection = sections.first {
            if case .day(1, _, _) = $0 { return true }
            return false
        }

        if case .day(_, _, let gamesOnDay) = firstDaySection {
            #expect(gamesOnDay.count == 1)
            #expect(gamesOnDay.first?.game.id == game.id)
        } else {
            Issue.record("Expected day section with games")
        }
    }

    @Test("travel segments appear in sections")
    func travelSegmentsAppear() {
        let startDate = TestClock.calendar.startOfDay(for: TestClock.now)
        let travel = TestFixtures.travelSegment(from: "New York", to: "Boston")
        let (baseTrip, days) = makeTrip(
            cities: ["New York", "Boston"],
            startDate: startDate,
            daysPerStop: 1
        )

        // Create trip with travel segment
        var trip = baseTrip
        trip.travelSegments = [travel]

        // Build without overrides - travel appears at default position
        let sectionsDefault = ItinerarySectionBuilder.build(
            trip: trip,
            tripDays: days,
            games: [:],
            travelOverrides: [:],
            itineraryItems: [],
            allowCustomItems: false
        )

        let travelSections = sectionsDefault.filter {
            if case .travel = $0 { return true }
            return false
        }

        // TravelPlacement should place the travel segment
        #expect(travelSections.count == 1)

        // Verify travel appears before day 2 (arrival day)
        if let travelIdx = sectionsDefault.firstIndex(where: {
            if case .travel = $0 { return true }
            return false
        }) {
            let nextIdx = sectionsDefault.index(after: travelIdx)
            if nextIdx < sectionsDefault.count,
               case .day(let dayNum, _, _) = sectionsDefault[nextIdx] {
                #expect(dayNum == 2)
            }
        }
    }

    @Test("custom items included when allowCustomItems is true")
    func customItemsIncluded() {
        let startDate = TestClock.calendar.startOfDay(for: TestClock.now)
        let (trip, days) = makeTrip(cities: ["New York"], startDate: startDate)

        let customItem = ItineraryItem(
            tripId: trip.id,
            day: 1,
            sortOrder: 1.0,
            kind: .custom(CustomInfo(title: "Lunch at Joe's", icon: "fork.knife"))
        )

        let sectionsWithItems = ItinerarySectionBuilder.build(
            trip: trip,
            tripDays: days,
            games: [:],
            travelOverrides: [:],
            itineraryItems: [customItem],
            allowCustomItems: true
        )

        let sectionsWithoutItems = ItinerarySectionBuilder.build(
            trip: trip,
            tripDays: days,
            games: [:],
            travelOverrides: [:],
            itineraryItems: [customItem],
            allowCustomItems: false
        )

        let customSectionsWithItems = sectionsWithItems.filter { $0.isCustomItem }
        let addButtonSections = sectionsWithItems.filter {
            if case .addButton = $0 { return true }
            return false
        }
        let customSectionsWithoutItems = sectionsWithoutItems.filter { $0.isCustomItem }

        #expect(customSectionsWithItems.count == 1)
        #expect(addButtonSections.count >= 1)
        #expect(customSectionsWithoutItems.count == 0)
    }

    @Test("stableTravelAnchorId format is consistent")
    func stableTravelAnchorIdFormat() {
        let segment = TestFixtures.travelSegment(from: "New York", to: "Boston")
        let id = ItinerarySectionBuilder.stableTravelAnchorId(segment, at: 0)
        #expect(id.hasPrefix("travel:0:"))
        #expect(id.contains("->"))
    }

    @Test("empty trip produces no sections")
    func emptyTripProducesNoSections() {
        let trip = TestFixtures.trip(stops: [])
        let sections = ItinerarySectionBuilder.build(
            trip: trip,
            tripDays: [],
            games: [:],
            travelOverrides: [:],
            itineraryItems: [],
            allowCustomItems: false
        )
        #expect(sections.isEmpty)
    }
}