import Foundation

struct Product: Identifiable, Hashable {
    static func == (lhs: Product, rhs: Product) -> Bool {
        lhs.id == rhs.id
    }

    func hash(into hasher: inout Hasher) {
        hasher.combine(id)
    }

    let id: Int
    let barcode: String
    let name: String
    let brand: String
    let imageUrl: String?
    let score: Int              // 0-100 weighted index
    let novaGroup: Int          // 1-4
    let servingSize: String
    let calories: Double
    let fat: Double
    let saturatedFat: Double
    let carbs: Double
    let sugar: Double
    let fiber: Double
    let protein: Double
    let sodium: Double
    let ingredients: String
    let dietaryTags: [String]   // ["vegan", "gluten-free", etc.]

    init(json: [String: Any]) {
        // Handle nested structures from API
        let rating = json["Rating"] as? [String: Any] ?? [:]
        let nutrition = json["Nutrition"] as? [String: Any] ?? [:]
        let dietary = json["Dietary"] as? [String: Any] ?? [:]

        id = JSON.parseInt(json["id"] ?? json["ID"] ?? json["productId"])
        barcode = JSON.parseString(json["barcode"] ?? json["Barcode"] ?? json["upc"])
        name = JSON.parseString(json["name"] ?? json["Name"] ?? json["productName"])
        brand = JSON.parseString(json["brand"] ?? json["Brand"] ?? json["brandName"])
        imageUrl = JSON.parseOptionalString(json["imageUrl"] ?? json["ImageURL"] ?? json["image"])

        // Score from Rating.OverallScore or top-level
        score = JSON.parseInt(rating["OverallScore"] ?? json["score"] ?? json["Score"])
        novaGroup = JSON.parseInt(json["novaGroup"] ?? json["NovaGroup"] ?? json["nova"])

        // Nutrition from nested object or top-level
        servingSize = JSON.parseString(nutrition["ServingSize"] ?? json["servingSize"] ?? json["ServingSize"])
        calories = JSON.parseDouble(nutrition["Calories"] ?? json["calories"] ?? json["Calories"])
        fat = JSON.parseDouble(nutrition["Fat"] ?? json["fat"] ?? json["Fat"])
        saturatedFat = JSON.parseDouble(nutrition["SaturatedFat"] ?? json["saturatedFat"] ?? json["SaturatedFat"])
        carbs = JSON.parseDouble(nutrition["Carbohydrates"] ?? json["carbs"] ?? json["Carbs"])
        sugar = JSON.parseDouble(nutrition["Sugars"] ?? json["sugar"] ?? json["Sugar"])
        fiber = JSON.parseDouble(nutrition["Fiber"] ?? json["fiber"] ?? json["Fiber"])
        protein = JSON.parseDouble(nutrition["Protein"] ?? json["protein"] ?? json["Protein"])
        sodium = JSON.parseDouble(nutrition["Sodium"] ?? json["sodium"] ?? json["Sodium"])

        ingredients = JSON.parseString(json["ingredients"] ?? json["Ingredients"])

        // Build dietary tags from Dietary object or use existing array
        var tags: [String] = []
        if JSON.parseBool(dietary["IsVegan"]) { tags.append("Vegan") }
        if JSON.parseBool(dietary["IsVegetarian"]) { tags.append("Vegetarian") }
        if JSON.parseBool(dietary["IsGlutenFree"]) { tags.append("Gluten-Free") }
        if JSON.parseBool(dietary["IsDairyFree"]) { tags.append("Dairy-Free") }
        if JSON.parseBool(dietary["IsNutFree"]) { tags.append("Nut-Free") }
        if JSON.parseBool(dietary["IsOrganic"]) { tags.append("Organic") }

        if tags.isEmpty {
            dietaryTags = JSON.parseStringArray(json["dietaryTags"] ?? json["DietaryTags"] ?? json["tags"])
        } else {
            dietaryTags = tags
        }
    }

    init(
        id: Int,
        barcode: String,
        name: String,
        brand: String,
        imageUrl: String? = nil,
        score: Int,
        novaGroup: Int,
        servingSize: String,
        calories: Double,
        fat: Double,
        saturatedFat: Double,
        carbs: Double,
        sugar: Double,
        fiber: Double,
        protein: Double,
        sodium: Double,
        ingredients: String,
        dietaryTags: [String]
    ) {
        self.id = id
        self.barcode = barcode
        self.name = name
        self.brand = brand
        self.imageUrl = imageUrl
        self.score = score
        self.novaGroup = novaGroup
        self.servingSize = servingSize
        self.calories = calories
        self.fat = fat
        self.saturatedFat = saturatedFat
        self.carbs = carbs
        self.sugar = sugar
        self.fiber = fiber
        self.protein = protein
        self.sodium = sodium
        self.ingredients = ingredients
        self.dietaryTags = dietaryTags
    }

    // MARK: - Computed Properties
    var imageURL: URL? {
        guard let imageUrl = imageUrl else { return nil }
        return URL(string: imageUrl)
    }

    var scoreColor: ScoreColor {
        switch score {
        case 80...100: return .excellent
        case 50..<80: return .good
        case 30..<50: return .fair
        default: return .poor
        }
    }

    var novaColor: NovaColor {
        switch novaGroup {
        case 1: return .nova1
        case 2: return .nova2
        case 3: return .nova3
        default: return .nova4
        }
    }

    enum ScoreColor {
        case excellent, good, fair, poor

        var color: String {
            switch self {
            case .excellent: return "scoreGreen"
            case .good: return "scoreYellow"
            case .fair: return "scoreOrange"
            case .poor: return "scoreRed"
            }
        }
    }

    enum NovaColor {
        case nova1, nova2, nova3, nova4

        var color: String {
            switch self {
            case .nova1: return "novaGreen"
            case .nova2: return "novaYellow"
            case .nova3: return "novaOrange"
            case .nova4: return "novaRed"
            }
        }

        var label: String {
            switch self {
            case .nova1: return "Unprocessed"
            case .nova2: return "Processed ingredients"
            case .nova3: return "Processed"
            case .nova4: return "Ultra-processed"
            }
        }
    }
}