/*
 * Copyright 2001-2013, Haiku, Inc.
 * Distributed under the terms of the MIT license.
 *
 * Authors:
 *              Adi Oanca <adioanca@myrealbox.com>
 *              Axel Dörfler, axeld@pinc-software.de
 *              Stephan Aßmus, <superstippi@gmx.de>
 */


#include "Screen.h"

#include "BitmapManager.h"
#include "DrawingEngine.h"
#include "HWInterface.h"

#include <Accelerant.h>
#include <Point.h>
#include <GraphicsDefs.h>

#include <stdlib.h>
#include <stdio.h>


static float
get_mode_frequency(const display_mode& mode)
{
        // Taken from Screen preferences
        float timing = float(mode.timing.h_total * mode.timing.v_total);
        if (timing == 0.0f)
                return 0.0f;

        return rint(10 * float(mode.timing.pixel_clock * 1000)
                / timing) / 10.0;
}


//      #pragma mark -


Screen::Screen(::HWInterface *interface, int32 id)
        :
        fID(id),
        fHWInterface(interface),
        fDriver(interface != NULL ? interface->CreateDrawingEngine() : NULL)
{
}


Screen::Screen()
        :
        fID(-1)
{
}


Screen::~Screen()
{
        Shutdown();
}


/*! Finds the mode in the mode list that is closest to the mode specified.
        As long as the mode list is not empty, this method will always succeed.
*/
status_t
Screen::Initialize()
{
        status_t status = B_NO_INIT;

        if (fHWInterface.IsSet()) {
                // init the graphics hardware
                status = fHWInterface->Initialize();
        }

        return status;
}


void
Screen::Shutdown()
{
        if (fHWInterface.IsSet())
                fHWInterface->Shutdown();
}


status_t
Screen::SetMode(const display_mode& mode)
{
        display_mode current;
        GetMode(current);
        if (!memcmp(&mode, &current, sizeof(display_mode)))
                return B_OK;

        gBitmapManager->SuspendOverlays();

        status_t status = fHWInterface->SetMode(mode);
                // any attached DrawingEngines will be notified

        gBitmapManager->ResumeOverlays();

        return status;
}


status_t
Screen::SetMode(uint16 width, uint16 height, uint32 colorSpace,
        const display_timing& timing)
{
        display_mode mode;
        mode.timing = timing;
        mode.space = colorSpace;
        mode.virtual_width = width;
        mode.virtual_height = height;
        mode.h_display_start = 0;
        mode.v_display_start = 0;
        mode.flags = 0;

        return SetMode(mode);
}


status_t
Screen::SetBestMode(uint16 width, uint16 height, uint32 colorSpace,
        float frequency, bool strict)
{
        // search for a matching mode
        display_mode* modes = NULL;
        uint32 count;
        status_t status = fHWInterface->GetModeList(&modes, &count);
        if (status < B_OK)
                return status;
        if (count <= 0)
                return B_ERROR;

        int32 index = _FindBestMode(modes, count, width, height, colorSpace,
                frequency);
        if (index < 0) {
                debug_printf("app_server: Finding best mode for %ux%u (%" B_PRIu32
                        ", %g Hz%s) failed\n", width, height, colorSpace, frequency,
                        strict ? ", strict" : "");

                if (strict) {
                        delete[] modes;
                        return B_ERROR;
                } else {
                        index = 0;
                        // Just use the first mode in the list
                        debug_printf("app_server: Use %ux%u (%" B_PRIu32 ") instead.\n",
                                modes[0].timing.h_total, modes[0].timing.v_total, modes[0].space);
                }
        }

        display_mode mode = modes[index];
        delete[] modes;

        float modeFrequency = get_mode_frequency(mode);
        display_mode originalMode = mode;
        bool adjusted = false;

        if (modeFrequency != frequency) {
                // adjust timing to fit the requested frequency if needed
                // (taken from Screen preferences application)
                mode.timing.pixel_clock = ((uint32)mode.timing.h_total
                        * mode.timing.v_total / 10 * int32(frequency * 10)) / 1000;
                adjusted = true;
        }
        status = SetMode(mode);
        if (status != B_OK && adjusted) {
                // try again with the unchanged mode
                status = SetMode(originalMode);
        }

        return status;
}


status_t
Screen::SetPreferredMode()
{
        display_mode mode;
        status_t status = fHWInterface->GetPreferredMode(&mode);
        if (status != B_OK)
                return status;

        return SetMode(mode);
}


void
Screen::GetMode(display_mode& mode) const
{
        fHWInterface->GetMode(&mode);
}


void
Screen::GetMode(uint16 &width, uint16 &height, uint32 &colorspace,
        float &frequency) const
{
        display_mode mode;
        fHWInterface->GetMode(&mode);

        width = mode.virtual_width;
        height = mode.virtual_height;
        colorspace = mode.space;
        frequency = get_mode_frequency(mode);
}


status_t
Screen::GetMonitorInfo(monitor_info& info) const
{
        return fHWInterface->GetMonitorInfo(&info);
}


void
Screen::SetFrame(const BRect& rect)
{
        // TODO: multi-monitor support...
}


BRect
Screen::Frame() const
{
        display_mode mode;
        fHWInterface->GetMode(&mode);

        return BRect(0, 0, mode.virtual_width - 1, mode.virtual_height - 1);
}


color_space
Screen::ColorSpace() const
{
        display_mode mode;
        fHWInterface->GetMode(&mode);

        return (color_space)mode.space;
}


/*!     \brief Returns the mode that matches the given criteria best.
        The "width" argument is the only hard argument, the rest will be adapted
        as needed.
*/
int32
Screen::_FindBestMode(const display_mode* modes, uint32 count,
        uint16 width, uint16 height, uint32 colorSpace, float frequency) const
{
        int32 bestDiff = 0;
        int32 bestIndex = -1;
        for (uint32 i = 0; i < count; i++) {
                const display_mode& mode = modes[i];
                if (mode.virtual_width != width)
                        continue;

                // compute some random equality score
                // TODO: check if these scores make sense
                int32 diff = 1000 * abs(mode.timing.v_display - height)
                        + int32(fabs(get_mode_frequency(mode) - frequency) * 10)
                        + 100 * abs((int)(mode.space - colorSpace));

                if (bestIndex == -1 || diff < bestDiff) {
                        bestDiff = diff;
                        bestIndex = i;
                }
        }

        return bestIndex;
}