using Age.Engine.Model;
using Age.Engine.Sys4;

namespace Age.Engine.Hosting;

public readonly record struct AdvWaitIndicatorConfig(
    int LayoutSlot, int X, int Y, int SurfaceSlot,
    int SourceX, int SourceY, int CellWidth, int CellHeight,
    int TerminalFrame, long FramePeriodMs)
{
    /// <summary>Select the current atlas frame. TerminalFrame is the exclusive native upper bound,
    /// so SYSTEM4's value 12 addresses the twelve cells 0 through 11.</summary>
    public int FrameAt(long elapsedMs)
    {
        int frameCount = System.Math.Max(1, TerminalFrame);
        long period = System.Math.Max(1, FramePeriodMs);
        return (int)(System.Math.Max(0, elapsedMs) / period % frameCount);
    }
}

public readonly record struct AdvAutoWaitState(
    bool Enabled, bool VoicePending, long PostVoiceDelayMs, long UnvoicedDelayMs);

public readonly record struct SurfaceRectFill(
    int SurfaceSlot, int X, int Y, int Width, int Height, int Alpha, long Rgb);

public readonly record struct SurfaceRectCopy(
    int SourceSurface, int DestinationSurface, int SourceX, int SourceY,
    int Width, int Height, int DestinationX, int DestinationY);

/// <summary>A synchronous AGE-owned diagnostic prompt after native body/context formatting.</summary>
public readonly record struct DiagnosticMessage(string Caption, string Text);

/// <summary>AGERc command 10's synchronous full-width text edit request and result.</summary>
public readonly record struct FullwidthTextEditRequest(string CurrentText, string InitialText);
public readonly record struct FullwidthTextEditResult(bool Accepted, string Text);

public enum SurfaceBlackFadeDirection
{
    FromBlack,
    ToBlack,
}

public interface IHost : IDiagnosticHost, ILifecycleHost, IAudioHost, IMovieHost
{
    /// <summary>Present AGERc's modal full-width editor. Cancel preserves CurrentText.</summary>
    FullwidthTextEditResult EditFullwidthString(FullwidthTextEditRequest request)
        => new(false, request.CurrentText);
    void ShowText(int offset, string text);
    void ShowText(AdvLiveTextRun run, int glyphDelayMilliseconds)
        => ShowText(run.SourceOffset, run.Text);
    AdvRetainedTextRunResult? ShowText(
        GfxState gfx,
        AdvTextLayoutPresentationBinding binding,
        AdvLiveTextRun run,
        int glyphDelayMilliseconds)
    {
        ShowText(run, glyphDelayMilliseconds);
        return null;
    }
    int MessageGlyphDelayMilliseconds => 50;
    void SetMessageGlyphDelayMilliseconds(int milliseconds) { }
    // Native ADV text subsystem: op 0x7a updates the selected layout's last 20-byte cursor record;
    // op 0x204 rasterizes a string into a numbered surface before 0x1fb binds that surface.
    void SetAdvTextCursor(int layoutSlot, int x, int y) { }
    void DrawStringToSurface(int surfaceSlot, int x, int y, string text) { }
    void DrawStringToSurface(int surfaceSlot, int x, int y, string text, AdvTextStyle style)
        => DrawStringToSurface(surfaceSlot, x, y, text);
    void ClearRenderedAdvTextLayout(int layoutSlot) { }
    void ResetRenderedAdvTextLayout(
        GfxState gfx, AdvTextLayoutPresentationBinding binding)
        => ClearRenderedAdvTextLayout(binding.LayoutSlot);
    void RenderTextHistory(AdvTextHistoryRenderBatch batch) { }
    bool RenderTextHistory(
        GfxState gfx,
        AdvTextLayoutPresentationBinding binding,
        AdvTextHistoryRenderBatch batch)
    {
        RenderTextHistory(batch);
        return false;
    }
    // History render batches are transient bindings, unlike the retained backlog itself. HISTORY.BIN's
    // recording re-enable at exit ends that presentation and drops every bound target layout.
    void EndTextHistoryPresentation() { }
    void EndTextHistoryPresentation(GfxState gfx) => EndTextHistoryPresentation();
    int MessageWindowAlphaSetting => 0;
    void SetMessageWindowAlphaSetting(int value) { }
    void FillSurfaceRect(SurfaceRectFill fill) { }
    void CopySurfaceRect(SurfaceRectCopy copy) { }
    void PresentObjectRange(GfxState gfx, long firstHandle, long count) { }
    void ConfigureAdvWaitIndicator(AdvWaitIndicatorConfig config) { }
    // Op 0x212 supplies the ordinary retained handle used to publish the configured atlas cell.
    void BindAdvWaitIndicator(
        AdvTextLayoutPresentationBinding binding,
        AdvTextLayoutSnapshot layout) { }
    // Op 0x1ce explicitly starts/stops the same animated marker that op 0x72 starts for an ADV wait.
    void SetAdvWaitIndicatorEnabled(bool enabled) { }
    // Op 0x20a republishes one retained ADV text layout and includes the current marker frame when active.
    void PublishAdvTextLayout(int layoutSlot) { }
    void PublishAdvTextLayout(
        GfxState gfx, AdvTextLayoutPresentationBinding binding)
        => PublishAdvTextLayout(binding.LayoutSlot);
    // Op 0x199 temporarily yields the active ADV page into its registered hide-window coroutine.
    // The retained scene continues to render, but the text layout and its wait marker are suspended
    // until op 0x7c restores the saved page PC.
    void SetAdvPagePresentationSuspended(bool suspended) { }
    void SetAdvPagePresentationSuspended(GfxState gfx, bool suspended)
        => SetAdvPagePresentationSuspended(suspended);
    void WaitForInput();
    void WaitForInput(int layoutSlot) => WaitForInput();
    // Interactive hosts service script callbacks on the VM thread while the enclosing ADV page remains
    // parked. The callback returns true while another queued input callback is ready to run.
    void WaitForInput(int layoutSlot, Func<bool> serviceInputCallback)
    {
        while (serviceInputCallback()) { }
        WaitForInput(layoutSlot);
    }
    void WaitForInput(int layoutSlot, Func<bool> serviceInputCallback,
                      Func<AdvAutoWaitState> autoWaitState)
        => WaitForInput(layoutSlot, serviceInputCallback);
    void WakeInputCallbackService() { }
    void InputCallbackCompleted(GfxState gfx) { }
    // Generic AGE input-callback services (ops 0xcc/0xcd, 0xfb/0xff/0x100, 0x108).
    // Interactive hosts expose the same monotonic clock used by their frame scheduler.
    long InputClockMilliseconds => Environment.TickCount64;
    void SetCursorResource(long resourceId) { }
    void ClearCursorResource() { }
    // Native 0x1c7/0x1cc query two distinct ADV skip channels. Headless and non-interactive
    // hosts default to normal playback; the Godot host supplies the live interactive values.
    void SetMessageSkipActive(bool active) { }
    // Logical action 6 is the native hold-to-fast-forward channel. Keep it separate from the
    // persistent op-0x88 channel so releasing the key cannot turn off the user's Skip toggle.
    void SetPhysicalMessageSkipActive(bool active) { }
    bool IsMessageSkipActive => false;
    // Optional diagnostic override. Native ReadTextDB state is VM/profile-owned; interactive hosts
    // normally leave this false.
    bool IsAdvReadSkipActive => false;
    // Normal playback reaches op 0x21c and parks until a queued 0x223 transition completes. The
    // read/message-skip branch reaches op 0x20c and presents the completed endpoint immediately.
    void WaitForForegroundTransition(GfxState gfx) { }
    void PresentFrame(GfxState gfx) { }
    // Legacy SYS4 screen-transition family (ops 0x21, 0x22, and 0x25): scripts render complete
    // frames into numbered surfaces, then block while the engine alpha-composites an endpoint.
    // Native bypasses the timed service when ADV fast-forward is already active at opcode dispatch.
    void FadeSurfaceWithBlack(
        GfxState gfx, int surface, long intervalArgument, SurfaceBlackFadeDirection direction,
        bool forceEndpoint = false) { }
    void CrossfadeSurfaces(
        GfxState gfx, int sourceSurface, int targetSurface, long intervalArgument,
        bool forceEndpoint = false) { }
    void CreateTexture(int slot, int width, int height);
    /// <summary>Return a stable RGBA snapshot of one numbered surface, or null when unavailable.</summary>
    RgbaImage? CaptureSurfacePixels(int slot) => null;
    /// <summary>Replace one numbered surface from decoded RGBA pixels. False means unsupported.</summary>
    bool ReplaceSurfacePixels(int slot, RgbaImage image) => false;
    void SetTexture(long resourceId, int slot);
    void SetTexture(long resourceId, int slot, long colorKey) => SetTexture(resourceId, slot);
    void ReleaseSurface(int slot) { }
    /// <summary>Clear the selected target's pixels; -1 denotes the main backbuffer.</summary>
    void ClearRenderTarget(int surfaceSlot) { }
    void ReleaseSurfaceRange(int firstSlot, int count)
    {
        for (int slot = firstSlot; slot < firstSlot + count; slot++) ReleaseSurface(slot);
    }
    void DrawTexture(int slot, int srcX, int srcY, int width, int height, int dstX, int dstY);
    (int Width, int Height) GetTextureSize(int slot);
}