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>Opcode 0x24d's captured-range movie-mask transition. The movie's decoded green channel
/// becomes a byte-per-pixel alpha mask over SourceRange in the scratch surface.</summary>
public readonly record struct MovieMaskTransitionRequest(
    long CommandKey, int SurfaceSlot, long SourceRangeStart, int SourceRangeCount,
    int X, int Y, int Width, int Height, long Mode, long ResourceId,
    long StartDelayMs, long DurationMs);

/// <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
{
    /// <summary>Report a recoverable runtime discrepancy while allowing script execution to continue.</summary>
    void ReportWarning(string message) => System.Console.Error.WriteLine(message);
    /// <summary>Present a modal diagnostic and return only after the user dismisses it.</summary>
    void ShowDiagnosticMessage(DiagnosticMessage message)
        => System.Console.Error.WriteLine($"{message.Caption}: {message.Text}");
    /// <summary>Present AGERc's modal full-width editor. Cancel preserves CurrentText.</summary>
    FullwidthTextEditResult EditFullwidthString(FullwidthTextEditRequest request)
        => new(false, request.CurrentText);
    // Script context is retained for diagnostics/page location; resource operands are universal packed ids.
    void EnterScriptContext(string scriptName) { }
    void ExitScriptContext() { }
    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() { }
    void Sleep(long duration);
    // Native op-0xd5 pacing sleeps inside run-state 0x40 without publishing retained gfx state.
    // Interactive hosts must keep this distinct from presentation-capable script op-0xc8 sleep.
    void WaitForTimedCallbackDeadline(long duration) => Sleep(duration);
    void FrameYield();
    // Native op 0x9 resets scene-owned host services before reloading root script resource 0.
    // Global banks, engine configuration, decoded-asset caches, and persistent profile state survive.
    void ResetSceneContext() { }
    // 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);
    void PlayBgm(long id);
    // Ordinary op 0xbf is VM-filtered so reasserting the current track is idempotent. Ops
    // 0xb7/0xb9 deliberately bypass that guard and restart with logical loop/one-shot mode.
    void RestartBgm(long id, int startMode) => PlayBgm(id);
    // Op 0xb8 releases the current source rather than merely applying a zero-volume envelope.
    void StopBgm() => FadeBgm(0, 0);
    void PlayVoice(long id);
    // Native voice playback retains a second start argument: ordinary dialogue passes 0,
    // while History replay (0x1bd) passes 1. Existing non-audio hosts may ignore it.
    void PlayVoice(long id, int playbackVariant) => PlayVoice(id);
    void ScheduleVoicePlayback(long id, int playbackVariant, long delayMs) { }
    // Native op 0x1cf stores a transient control mask. Bit 0 suppresses the automatic
    // BGM attenuation normally applied when a voice starts.
    void SetVoiceBgmDuckControl(long flags) { }
    void LoadSoundEffect(long resourceId, int channel) { }
    void StartSoundEffect(int channel) { }
    // Ops 0xb5/0xba share the native channel-start worker. Mode 0 plays once; mode 1
    // rewinds the decoder at EOF. The one-argument seam remains for simple hosts.
    void StartSoundEffect(int channel, int startMode) => StartSoundEffect(channel);
    // Native SetDelay (op 0x2bf) starts an already-loaded channel after delayMs.
    // startMode is forwarded to the same worker used by immediate SFX starts.
    void ScheduleSoundEffectStart(int channel, int startMode, long delayMs) { }
    void ReleaseSoundEffect(int channel) { }
    void FadeBgm(int targetPercent, long durationMs) { }
    // AGE's sound:* settings registry is VM-owned; the host applies changes to active playback.
    void ApplyAudioVolume(int category, int basisPoints) { }
    void ApplyAudioRouteEnabled(int category, bool enabled) { }
    // Native op 0x236 binds a movie decoder to an existing retained texture surface.
    // Playback is non-modal: the VM advances to the following instruction while the host publishes frames.
    /// <returns>The initialized movie graph's stop position in truncated integer milliseconds, or null
    /// when the host could not obtain usable timing metadata. Native op 0x23f queries this state
    /// immediately after 0x236 returns.</returns>
    long? PlayMovieToSurface(long resourceId, int surfaceSlot, long movieFlags, long syncMask) => null;
    // Native op 0x241 uses the same graph/surface lifecycle as 0x236, but seeks the graph before
    // playback configuration. Hosts without positioned decoding may fall back to ordinary playback.
    long? PlayMovieToSurfaceAtPosition(
        long resourceId, int surfaceSlot, long movieFlags, long syncMask, long positionMs)
        => PlayMovieToSurface(resourceId, surfaceSlot, movieFlags, syncMask);
    // Native op 0x24d captures a retained range into the scratch surface, then publishes each
    // decoded movie frame's green channel as an exact packed-alpha mask. A nonvisual host completes
    // the lifecycle immediately so a following 0x21c can never strand script execution.
    void PlayMovieMaskTransition(GfxState gfx, MovieMaskTransitionRequest request)
    {
        gfx.QueueMovieMaskTransition(request);
        gfx.CompleteMovieMaskTransition(request.SurfaceSlot);
    }
    bool IsMovieSurfaceActive(int surfaceSlot) => false;
    // Native op 0x20f uses a universal packed id and parks script execution until the movie
    // reaches EOF or the player cancels it. The decoder remains asynchronous; the interactive host
    // owns the modal wait so its render loop can continue publishing frames.
    void PlayModalMovieToSurface(long resourceId, int surfaceSlot, long movieFlags) { }
}