RIT-Dining/TigerDine/Data/DiningModel.swift

//
//  DiningModel.swift
//  TigerDine
//
//  Created by Campbell on 10/1/25.
//

import SwiftUI

@Observable
class DiningModel {
    var locationsByDay = [[DiningLocation]]()
    var daysRepresented = [Date]()
    var lastRefreshed: Date?
    
    // External models that should be nested under this one.
    var favorites = Favorites()
    var notifyingChefs = NotifyingChefs()
    var visitingChefPushes = VisitingChefPushesModel()
    
    /// This is the actual method responsible for making requests to the API for the current day and next 6 days to collect all of the information that the app needs for the various view. Making it part of the model allows it to be updated from any view at any time, and prevents excess API requests (if you never refresh, the app will never need to make more than 7 calls per launch).
    func getHoursByDay() async throws {
        let calendar = Calendar.current
        let today = calendar.startOfDay(for: Date())
        let week: [Date] = (0..<7).compactMap { offset in
            calendar.date(byAdding: .day, value: offset, to: today)
        }
        daysRepresented = week
        var newLocationsByDay = [[DiningLocation]]()
        for day in week {
            let dateString = day.formatted(.iso8601
                .year().month().day()
                .dateSeparator(.dash))
            switch await getAllDiningInfo(date: dateString) {
            case .success(let locations):
                var newDiningLocations = [DiningLocation]()
                for i in 0..<locations.locations.count {
                    let diningInfo = parseLocationInfo(location: locations.locations[i], forDate: day)
                    newDiningLocations.append(diningInfo)
                }
                newLocationsByDay.append(newDiningLocations)
            case .failure(let error):
                throw(error)
            }
        }
        locationsByDay = newLocationsByDay
        lastRefreshed = Date()
    }
    
    /// Iterates through all of the locations and updates their open status indicator based on the current time. Does a replace to make sure that it updates any views observing this model.
    func updateOpenStatuses() {
        locationsByDay = locationsByDay.map { day in
            day.map { location in
                var location = location
                location.updateOpenStatus()
                return location
            }
        }
    }
    
    /// Schedules and saves push notifications for all enabled visiting chefs.
    func scheduleAllPushes() async {
        for day in locationsByDay {
            for location in day {
                if let visitingChefs = location.visitingChefs {
                    for chef in visitingChefs {
                        if notifyingChefs.contains(chef.name) {
                            await visitingChefPushes.scheduleNewPush(
                                name: chef.name,
                                location: location.name,
                                startTime: chef.openTime,
                                endTime: chef.closeTime
                            )
                        }
                    }
                }
            }
        }
        // Run a cleanup task once we're done scheduling.
        await cleanupPushes()
    }
    
    /// Cleans up old push notifications that have already been delivered so that we're not still tracking them forever.
    func cleanupPushes() async {
        let now = Date()
        for push in visitingChefPushes.pushes {
            if now > push.endTime {
                visitingChefPushes.pushes.remove(at: visitingChefPushes.pushes.firstIndex(of: push)!)
            }
        }
    }
    
    /// Cancels all pending push notifications. Used when disabling push notifications as a whole.
    func cancelAllPushes() async {
        let uuids = visitingChefPushes.pushes.map(\.uuid)
        await cancelVisitingChefNotifs(uuids: uuids)
        visitingChefPushes.pushes.removeAll()
    }
    
    /// Schedules and saves push notifications for a specific visiting chef.
    func schedulePushesForChef(_ chefName: String) async {
        for day in locationsByDay {
            for location in day {
                if let visitingChefs = location.visitingChefs {
                    for chef in visitingChefs {
                        if chef.name == chefName && notifyingChefs.contains(chef.name) {
                            await visitingChefPushes.scheduleNewPush(
                                name: chef.name,
                                location: location.name,
                                startTime: chef.openTime,
                                endTime: chef.closeTime
                            )
                        }
                    }
                }
            }
        }
    }
}