//
//  TankCatalogTests.swift
//  GasTankARTests
//
//  Created by Dennis Nemec on 14.09.26.
//

import Testing
import Foundation
@testable import GasTankAR

/// Prüft das Laden/Decodieren des Tank-Katalogs aus JSON sowie die abgeleiteten
/// Abfragen (verfügbare Größen/Farben, Auflösung & Normalisierung der Auswahl).
struct TankCatalogTests {

    // Kleiner, in sich konsistenter Beispielkatalog für Query-Tests.
    private static let sampleJSON = """
    {
      "sizeDisplayNames": { "t1_2": "1,2 t", "t2_9": "2,9 t" },
      "colorDisplayNames": { "white": "Weiß", "green": "Hellgrün", "olive": "Olivgrün" },
      "tanks": [
        { "size": "t1_2", "color": "white", "placement": "aboveGround", "modelPath": "DG-2700_wh.usdz" },
        { "size": "t1_2", "color": "green", "placement": "aboveGround", "modelPath": "DG-2700_mi.usdz" },
        { "size": "t1_2", "color": "olive", "placement": "belowGround", "modelPath": "DG-2700_ol.usdz" },
        { "size": "t2_9", "color": "white", "placement": "aboveGround", "modelPath": "DG-6400_wh.usdz" },
        { "size": "t2_9", "color": "olive", "placement": "belowGround", "modelPath": "DG-6400_ol.usdz" }
      ]
    }
    """

    private static func sampleCatalog() throws -> TankCatalog {
        let loader = DataTankCatalogLoader(data: Data(sampleJSON.utf8))
        return TankCatalog(file: try loader.load())
    }

    // MARK: - Decoding

    @Test func decodesAllFieldsFromJSON() throws {
        let catalog = try Self.sampleCatalog()
        let def = try #require(catalog.definitions.first)

        #expect(def.size == .t1_2)
        #expect(def.color == .white)
        #expect(def.placement == .aboveGround)
        #expect(def.modelPath == "DG-2700_wh.usdz")
        #expect(def.modelResourceName == "DG-2700_wh")
        #expect(def.modelFileExtension == "usdz")
    }

    @Test func decodesDisplayNameMappings() throws {
        let catalog = try Self.sampleCatalog()
        #expect(catalog.sizeDisplayNames["t1_2"] == "1,2 t")
        #expect(catalog.colorDisplayNames["olive"] == "Olivgrün")
    }

    @Test func displayNameFallsBackToRawValueWhenMissing() {
        // Katalog ohne Mappings → Anzeigename ist der rawValue.
        let catalog = TankCatalog(definitions: [])
        #expect(catalog.displayName(for: TankSize.t2_1) == "t2_1")
        #expect(catalog.displayName(for: TankColor.green) == "green")
    }

    @Test func missingResourceThrows() {
        let loader = BundleTankCatalogLoader(
            bundle: .main,
            resourceName: "Datei-die-nicht-existiert",
            resourceExtension: "json"
        )
        #expect(throws: TankCatalogLoaderError.self) {
            _ = try loader.load()
        }
    }

    @Test func emptyCatalogWhenLoaderFails() {
        let loader = BundleTankCatalogLoader(resourceName: "gibt-es-nicht")
        let catalog = TankCatalog(loader: loader)
        #expect(catalog.definitions.isEmpty)
    }

    // MARK: - Abgeleitete Abfragen

    @Test func availableColorsDependOnPlacement() throws {
        let catalog = try Self.sampleCatalog()
        #expect(catalog.colors(for: .t1_2, placement: .aboveGround) == [.white, .green])
        #expect(catalog.colors(for: .t1_2, placement: .belowGround) == [.olive])
    }

    @Test func availableSizesPerPlacement() throws {
        let catalog = try Self.sampleCatalog()
        #expect(catalog.sizes(for: .aboveGround) == [.t1_2, .t2_9])
        #expect(catalog.sizes(for: .belowGround) == [.t1_2, .t2_9])
    }

    @Test func placementsPreserveOrder() throws {
        let catalog = try Self.sampleCatalog()
        #expect(catalog.placements == [.aboveGround, .belowGround])
    }

    @Test func displayNamesResolveFromCatalog() throws {
        let catalog = try Self.sampleCatalog()
        #expect(catalog.displayName(for: TankSize.t2_9) == "2,9 t")
        #expect(catalog.displayName(for: TankColor.olive) == "Olivgrün")
    }

    // MARK: - Auflösung & Normalisierung

    @Test func definitionMatchesExactSelection() throws {
        let catalog = try Self.sampleCatalog()
        let tank = Tank(size: .t2_9, color: .olive, placement: .belowGround)
        #expect(catalog.definition(for: tank)?.modelPath == "DG-6400_ol.usdz")
    }

    @Test func normalizesInconsistentColorForPlacement() throws {
        let catalog = try Self.sampleCatalog()
        // Weiß gibt es unterirdisch nicht → sollte auf Olivgrün korrigiert werden.
        let tank = Tank(size: .t2_9, color: .white, placement: .belowGround)
        let normalized = catalog.normalized(tank)
        #expect(normalized.color == .olive)
        #expect(catalog.definition(for: normalized) != nil)
    }

    @Test func resolvedDefinitionHealsLegacySelection() throws {
        let catalog = try Self.sampleCatalog()
        // Altdaten: unterirdisch + weiß → muss trotzdem das Olivgrün-Modell liefern.
        let legacy = Tank(size: .t2_9, color: .white, placement: .belowGround)
        #expect(catalog.resolvedDefinition(for: legacy)?.modelPath == "DG-6400_ol.usdz")
    }

    @Test func validSelectionStaysUnchanged() throws {
        let catalog = try Self.sampleCatalog()
        let tank = Tank(size: .t1_2, color: .green, placement: .aboveGround)
        #expect(catalog.normalized(tank) == tank)
    }
}