import UIKit

public protocol RDEPUBReaderDisplayEnvironment: AnyObject {
    var currentBrightness: CGFloat { get set }
    var fallbackViewportSize: CGSize { get }
}

public final class RDEPUBUIScreenEnvironment: RDEPUBReaderDisplayEnvironment {
    public init() {}

    public var currentBrightness: CGFloat {
        get { CGFloat(UIScreen.main.brightness) }
        set { UIScreen.main.brightness = newValue }
    }

    public var fallbackViewportSize: CGSize {
        UIScreen.main.bounds.size
    }
}

public struct RDEPUBReaderDependencies {
    public var environment: any RDEPUBReaderDisplayEnvironment
    public var makeParser: () -> RDEPUBParser
    public var makePaginator: () -> RDEPUBPaginator
    public var makeTextBookBuilder: (RDEPUBTextRenderer, RDEPUBTextBookCache?, RDEPUBTextLayoutConfig) -> RDEPUBTextBookBuilder
    public var makePlainTextBookBuilder: (RDEPUBTextRenderer, RDEPUBTextLayoutConfig) -> RDPlainTextBookBuilder
    public var makeTextRenderer: (RDEPUBTextRenderingEngine) -> RDEPUBTextRenderer

    public init(
        environment: any RDEPUBReaderDisplayEnvironment,
        makeParser: @escaping () -> RDEPUBParser,
        makePaginator: @escaping () -> RDEPUBPaginator,
        makeTextBookBuilder: @escaping (RDEPUBTextRenderer, RDEPUBTextBookCache?, RDEPUBTextLayoutConfig) -> RDEPUBTextBookBuilder,
        makePlainTextBookBuilder: @escaping (RDEPUBTextRenderer, RDEPUBTextLayoutConfig) -> RDPlainTextBookBuilder,
        makeTextRenderer: @escaping (RDEPUBTextRenderingEngine) -> RDEPUBTextRenderer
    ) {
        self.environment = environment
        self.makeParser = makeParser
        self.makePaginator = makePaginator
        self.makeTextBookBuilder = makeTextBookBuilder
        self.makePlainTextBookBuilder = makePlainTextBookBuilder
        self.makeTextRenderer = makeTextRenderer
    }

    public static var live: RDEPUBReaderDependencies {
        RDEPUBReaderDependencies(
            environment: RDEPUBUIScreenEnvironment(),
            makeParser: { RDEPUBParser() },
            makePaginator: { RDEPUBPaginator() },
            makeTextBookBuilder: { renderer, cache, layoutConfig in
                RDEPUBTextBookBuilder(renderer: renderer, cache: cache, layoutConfig: layoutConfig)
            },
            makePlainTextBookBuilder: { renderer, layoutConfig in
                RDPlainTextBookBuilder(renderer: renderer, layoutConfig: layoutConfig)
            },
            makeTextRenderer: { engine in
                switch engine {
                case .dtCoreText:
                    return RDEPUBDTCoreTextRenderer()
                }
            }
        )
    }
}