// -----------------------------------------------------------------------------
// Lou-Ka — Agrégateur de logements à louer (province de Québec)
// Auteur : Simon-Pierre Boucher — contact@spboucher.ai
// API.swift : client HTTP vers l'API de production (www.lou-ka.com)
// -----------------------------------------------------------------------------
import Foundation

struct ListingFilters: Equatable {
    var q = ""
    var city = ""
    var sector = ""
    var unitType = ""
    var source = ""
    var priceMin: Int?
    var priceMax: Int?
    /// nil = peu importe · 0 = maintenant · 30/60/90 = d'ici n jours
    var dispoDays: Int?
    var petsOk = false
    /// nil = peu importe · true = meublé · false = non meublé
    var furnished: Bool?
    var areaMin: Int?

    var activeCount: Int {
        [q, city, sector, unitType, source].filter { !$0.isEmpty }.count
            + (priceMin != nil ? 1 : 0) + (priceMax != nil ? 1 : 0)
            + (dispoDays != nil ? 1 : 0) + (petsOk ? 1 : 0)
            + (furnished != nil ? 1 : 0) + (areaMin != nil ? 1 : 0)
    }
}

enum APIError: LocalizedError {
    case badStatus(Int)

    var errorDescription: String? {
        switch self {
        case .badStatus(let code): return "L'API a répondu \(code). Réessayez dans un instant."
        }
    }
}

enum API {
    static let base = URL(string: "https://www.lou-ka.com")!

    /// Date ISO à +n jours (paramètre `available_by`)
    static func isoInDays(_ n: Int) -> String {
        let d = Calendar.current.date(byAdding: .day, value: n, to: Date()) ?? Date()
        let f = DateFormatter()
        f.dateFormat = "yyyy-MM-dd"
        f.locale = Locale(identifier: "en_US_POSIX")
        return f.string(from: d)
    }

    static func get<T: Decodable>(_ path: String, query: [URLQueryItem] = []) async throws -> T {
        var comps = URLComponents(url: base.appendingPathComponent(path), resolvingAgainstBaseURL: false)!
        if !query.isEmpty { comps.queryItems = query }
        var req = URLRequest(url: comps.url!)
        req.timeoutInterval = 20
        req.setValue("LouKa-iOS/1.2", forHTTPHeaderField: "User-Agent")
        let (data, resp) = try await URLSession.shared.data(for: req)
        guard let http = resp as? HTTPURLResponse, (200..<300).contains(http.statusCode) else {
            throw APIError.badStatus((resp as? HTTPURLResponse)?.statusCode ?? -1)
        }
        return try JSONDecoder().decode(T.self, from: data)
    }

    static func listings(_ f: ListingFilters, limit: Int? = nil) async throws -> ListingsResponse {
        var q: [URLQueryItem] = []
        if !f.q.isEmpty { q.append(.init(name: "q", value: f.q)) }
        if !f.city.isEmpty { q.append(.init(name: "city", value: f.city)) }
        if !f.sector.isEmpty { q.append(.init(name: "sector", value: f.sector)) }
        if !f.unitType.isEmpty { q.append(.init(name: "unit_type", value: f.unitType)) }
        if !f.source.isEmpty { q.append(.init(name: "source", value: f.source)) }
        if let min = f.priceMin { q.append(.init(name: "price_min", value: String(min))) }
        if let max = f.priceMax { q.append(.init(name: "price_max", value: String(max))) }
        if f.petsOk { q.append(.init(name: "pets", value: "oui")) }
        if let furn = f.furnished { q.append(.init(name: "furnished", value: furn ? "1" : "0")) }
        if let days = f.dispoDays { q.append(.init(name: "available_by", value: isoInDays(days))) }
        if let area = f.areaMin { q.append(.init(name: "area_min", value: String(area))) }
        if let limit { q.append(.init(name: "limit", value: String(limit))) }
        return try await get("api/listings", query: q)
    }

    static func listing(uid: String) async throws -> Listing {
        try await get("api/listings/\(uid)")
    }

    static func facets(city: String? = nil) async throws -> Facets {
        var q: [URLQueryItem] = []
        if let city, !city.isEmpty { q.append(.init(name: "city", value: city)) }
        return try await get("api/facets", query: q)
    }

    static func sources() async throws -> SourcesResponse { try await get("api/sources") }
    static func stats() async throws -> Stats { try await get("api/stats") }
    static func detailedStats() async throws -> DetailedStats { try await get("api/stats/detailed") }
}