/* main.cpp
 *
 * Copyright (C) 2014: Dalton Nell, Slop Contributors (https://github.com/naelstrof/slop/graphs/contributors).
 *
 * This file is part of Slop.
 *
 * Slop is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Slop is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Slop.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <unistd.h>
#include <time.h>
#include <cstdio>
#include <sstream>
#include <execinfo.h>
#include <stdexcept>

#ifdef __MACH__
#include <mach/clock.h>
#include <mach/mach.h>
#endif

#include "x.hpp"
#include "selectrectangle.hpp"
#ifdef OPENGL_ENABLED
#include "glselectrectangle.hpp"
#endif //OPENGL_ENABLED
#include "xselectrectangle.hpp"
#include "cmdline.h"

// Work around lack of clock_gettime in OSX
// https://gist.github.com/jbenet/1087739
void current_utc_time(struct timespec *ts) {
    #ifdef __MACH__
        // OS X does not have clock_gettime, use clock_get_time
        clock_serv_t cclock;
        mach_timespec_t mts;
        host_get_clock_service( mach_host_self(), CALENDAR_CLOCK, &cclock );
        clock_get_time( cclock, &mts );
        mach_port_deallocate( mach_task_self(), cclock );
        ts->tv_sec = mts.tv_sec;
        ts->tv_nsec = mts.tv_nsec;
    #else
        clock_gettime( CLOCK_REALTIME, ts );
    #endif
}

int printSelection( std::string format, bool cancelled, int x, int y, int w, int h, int window ) {
    size_t pos = 0;
    while ( ( pos = format.find( "%", pos ) ) != std::string::npos ) {
        if ( pos + 1 > format.size() ) {
            fprintf( stderr, "Format error: %% found at the end of format string.\n" );
            return EXIT_FAILURE;
        }
        std::stringstream foo;
        switch( format[ pos + 1 ] ) {
            case '%':
                format.replace( pos, 2, "%" );
                pos += 1;
                break;
            case 'x':
            case 'X':
                foo << x;
                format.replace( pos, 2, foo.str() );
                break;
            case 'y':
            case 'Y':
                foo << y;
                format.replace( pos, 2, foo.str() );
                break;
            case 'w':
            case 'W':
                foo << w;
                format.replace( pos, 2, foo.str() );
                break;
            case 'h':
            case 'H':
                foo << h;
                format.replace( pos, 2, foo.str() );
                break;
            case 'g':
            case 'G':
                foo << w << 'x' << h << '+' << x << '+' << y;
                format.replace( pos, 2, foo.str() );
                break;
            case 'i':
            case 'I':
                foo << window;
                format.replace( pos, 2, foo.str() );
                break;
            case 'c':
            case 'C':
                format.replace( pos, 2, cancelled ? "true" : "false" );
                break;
            default:
                fprintf( stderr, "Format error: %%%c is an unknown replacement identifier.\n", format[ pos + 1 ] );
                fprintf( stderr, "Valid replacements: %%x, %%y, %%w, %%h, %%i, %%c, %%.\n" );
                return EXIT_FAILURE;
                break;
        }
    }
    pos = 0;
    while ( ( pos = format.find( "\\", pos ) ) != std::string::npos ) {
        if ( pos + 1 > format.size() ) {
            break;
        }
        if ( format[ pos + 1 ] == 'n' ) {
            format.replace( pos, 2, "\n" );
        }
        pos = pos + 1;
    }
    printf( "%s", format.c_str() );
    return EXIT_SUCCESS;
}

int parseColor( std::string arg, float* r, float* g, float* b, float* a ) {
    std::string copy = arg;
    int find = copy.find( "," );
    while( find != (int)copy.npos ) {
        copy.at( find ) = ' ';
        find = copy.find( "," );
    }

    // Just in case we didn't include an alpha value
    *a = 1;
    int num = sscanf( copy.c_str(), "%f %f %f %f", r, g, b, a );
    if ( num != 3 && num != 4 ) {
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}

void constrain( int sx, int sy, int ex, int ey, int padding, int minimumsize, int maximumsize, int* rsx, int* rsy, int* rex, int* rey ) {
    if ( minimumsize > maximumsize && maximumsize > 0 ) {
        fprintf( stderr, "Error: minimumsize is greater than maximumsize.\n" );
        exit( 1 );
    }
    int x = std::min( sx, ex );
    int y = std::min( sy, ey );
    // We add one to make sure we select the pixel under the mouse.
    int w = std::max( sx, ex ) - x + 1;
    int h = std::max( sy, ey ) - y + 1;
    // Make sure we don't turn inside out...
    if ( w + padding*2 >= 0 ) {
        x -= padding;
        w += padding*2;
    }
    if ( h + padding*2 >= 0 ) {
        y -= padding;
        h += padding*2;
    }
    if ( w < minimumsize ) {
        int diff = minimumsize - w;
        w = minimumsize;
        x -= diff/2;
    }
    if ( h < minimumsize ) {
        int diff = minimumsize - h;
        h = minimumsize;
        y -= diff/2;
    }
    if ( maximumsize > 0 ) {
        if ( w > maximumsize ) {
            int diff = w;
            w = maximumsize;
            x += diff/2 - maximumsize/2;
        }
        if ( h > maximumsize ) {
            int diff = h;
            h = maximumsize;
            y += diff/2 - maximumsize/2;
        }
    }
    // Center around mouse if we have a fixed size.
    if ( maximumsize == minimumsize && w == maximumsize && h == maximumsize ) {
        x = ex - maximumsize/2;
        y = ey - maximumsize/2;
    }
    *rsx = x;
    *rsy = y;
    *rex = x + w;
    *rey = y + h;
}

// Some complicated key detection to replicate key repeating
bool keyRepeat( KeySym key, double curtime, double repeatdelay, double* time, bool* memory ) {
    if ( xengine->keyPressed( key ) != *memory ) {
        if ( xengine->keyPressed( key ) ) {
            *memory = true;
            *time = curtime;
            return true;
        } else {
            *memory = false;
        }
    }
    if ( xengine->keyPressed( key ) && curtime - *time > repeatdelay ) {
        return true;
    }
    return false;
}

int app( int argc, char** argv ) {
    gengetopt_args_info options;
    int err = cmdline_parser( argc, argv, &options );
    if ( err != EXIT_SUCCESS ) {
        return EXIT_FAILURE;
    }
    int state = 0;
    bool running = true;
    bool opengl = options.opengl_flag;
    slop::SelectRectangle* selection = NULL;
    Window window = None;
    Window windowmemory = None;
    std::string xdisplay;
    if ( options.xdisplay_given ) {
        xdisplay = options.xdisplay_arg;
    } else {
        // If we weren't specifically given a xdisplay, we try
        // to parse it from environment variables
        char* display = getenv( "DISPLAY" );
        if ( display ) {
            xdisplay = display;
        } else {
            fprintf( stderr, "Warning: Failed to parse environment variable: DISPLAY. Using \":0\" instead.\n" );
            xdisplay = ":0";
        }
    }
    int padding = options.padding_arg;
    int borderSize = options.bordersize_arg;
    int tolerance = options.tolerance_arg;
    float r, g, b, a;
    err = parseColor( options.color_arg, &r, &g, &b, &a );
    if ( err != EXIT_SUCCESS ) {
        fprintf( stderr, "Error parsing color %s\n", options.color_arg );
        return EXIT_FAILURE;
    }
    float gracetime;
    err = sscanf( options.gracetime_arg, "%f", &gracetime );
    if ( err != 1 ) {
        fprintf( stderr, "Error parsing %s as a float for gracetime!\n", options.gracetime_arg );
        return EXIT_FAILURE;
    }
    bool highlight = options.highlight_flag;
    bool keyboard = !options.nokeyboard_flag;
    bool decorations = !options.nodecorations_flag;
    bool themeon = (bool)options.theme_given;
    std::string theme = options.theme_arg;
    bool shadergiven = (bool)options.shader_given;
    std::string shader = options.shader_arg;
    struct timespec start, time;
    int xoffset = 0;
    int yoffset = 0;
    int cx = 0;
    int cy = 0;
    int xmem = 0;
    int ymem = 0;
    int wmem = 0;
    int hmem = 0;
    int minimumsize = options.min_arg;
    int maximumsize = options.max_arg;
    bool pressedMemory[4];
    double pressedTime[4];
    for ( int i=0;i<4;i++ ) {
        pressedMemory[ i ] = false;
        pressedTime[ i ] = 0;
    }
    std::string format = options.format_arg;
    bool magenabled = options.magnify_flag;
    float magstrength = options.magstrength_arg;
    if ( options.magpixels_arg < 0 ) {
        fprintf( stderr, "Error: --magpixels < 0, it's an unsigned integer you twat. Stop trying to underflow me!\n" );
        return EXIT_FAILURE;
    }
    unsigned int magpixels = (unsigned int)options.magpixels_arg;
    cmdline_parser_free( &options );
#ifndef OPENGL_ENABLED
    if ( opengl || themeon || magenabled ) {
        throw std::runtime_error( "Slop wasn't compiled with OpenGL support, so themes, magnifications, and shaders are disabled! Try compiling it with the CMAKE_OPENGL_ENABLED set to true." );
    }
#else // OPENGL_ENABLED
    if ( ( themeon || magenabled || shadergiven ) && !opengl ) {
        throw std::runtime_error( "Slop needs --opengl enabled to use themes, shaders, or magnifications." );
    }
#endif

    // First we set up the x interface and grab the mouse,
    // if we fail for either we exit immediately.
    err = xengine->init( xdisplay.c_str() );
    if ( err != EXIT_SUCCESS ) {
        printSelection( format, true, 0, 0, 0, 0, None );
        return EXIT_FAILURE;
    }
    if ( !slop::isSelectRectangleSupported() ) {
        fprintf( stderr, "Error: Your X server doesn't support the XShape extension. There's nothing slop can do about this!\n" );
        fprintf( stderr, "  Try updating X and making sure you have XExtensions installed. (/usr/lib/libXext.so, /usr/include/X11/extensions/shape.h)\n" );
        return EXIT_FAILURE;
    }
    err = xengine->grabCursor( slop::Cross, gracetime );
    if ( err != EXIT_SUCCESS ) {
        printSelection( format, true, 0, 0, 0, 0, None );
        return EXIT_FAILURE;
    }
    if ( keyboard ) {
        err = xengine->grabKeyboard();
        if ( err ) {
            fprintf( stderr, "Warning: Failed to grab the keyboard. This is non-fatal, keyboard presses might fall through to other applications.\n" );
        }
    }
    current_utc_time( &start );
    double deltatime = 0;
    double curtime = double( start.tv_sec*1000000000L + start.tv_nsec )/1000000000.f;
    while ( running ) {
        current_utc_time( &time );
        // "ticking" the xengine makes it process all queued events.
        xengine->tick();
        // If the user presses any key on the keyboard, exit the application.
        // Make sure at least gracetime has passed before allowing canceling
        double newtime = double( time.tv_sec*1000000000L + time.tv_nsec )/1000000000.f;
        deltatime = newtime-curtime;
        curtime = newtime;
        double starttime = double( start.tv_sec*1000000000L + start.tv_nsec )/1000000000.f;
        if ( curtime - starttime > gracetime ) {
            if ( keyRepeat( XK_Up, curtime, 0.5, &pressedTime[ 0 ], &pressedMemory[ 0 ] ) ) {
                yoffset -= 1;
            }
            if ( keyRepeat( XK_Down, curtime, 0.5, &pressedTime[ 1 ], &pressedMemory[ 1 ] ) ) {
                yoffset += 1;
            }
            if ( keyRepeat( XK_Left, curtime, 0.5, &pressedTime[ 2 ], &pressedMemory[ 2 ] ) ) {
                xoffset -= 1;
            }
            if ( keyRepeat( XK_Right, curtime, 0.5, &pressedTime[ 3 ], &pressedMemory[ 3 ] ) ) {
                xoffset += 1;
            }
            // If we pressed enter we move the state onward.
            if ( xengine->keyPressed( XK_Return ) ) {
                // If we're highlight windows, just select the active window.
                if ( state == 0 ) {
                    state = 1;
                // If we're making a custom selection, select the custom selection.
                } else if ( state == 2 ) {
                    state = 3;
                }
            }
            // If we press any key other than the arrow keys or enter key, we shut down!
            if ( !( xengine->keyPressed( XK_Up ) || xengine->keyPressed( XK_Down ) || xengine->keyPressed( XK_Left ) || xengine->keyPressed( XK_Right ) ) &&
                !( xengine->keyPressed( XK_Return ) ) &&
                ( ( xengine->anyKeyPressed() && keyboard ) || xengine->mouseDown( 3 ) ) ) {
                printSelection( format, true, 0, 0, 0, 0, None );
                fprintf( stderr, "User pressed key. Canceled selection.\n" );
                state = -1;
                running = false;
            }
        }
        // Our adorable little state manager will handle what state we're in.
        switch ( state ) {
            default: {
                break;
            }
            case 0: {
                // If xengine has found a window we're hovering over (or if it changed)
                // create a rectangle around it so the user knows he/she can click on it.
                // --but only if the user wants us to
                if ( window != xengine->m_hoverWindow && tolerance > 0 ) {
                    slop::WindowRectangle t;
                    t.setGeometry( xengine->m_hoverWindow, decorations );
                    t.applyPadding( padding );
                    t.applyMinMaxSize( minimumsize, maximumsize );
                    // Make sure we only apply offsets to windows that we've forcibly removed decorations on.
                    if ( !selection ) {
#ifdef OPENGL_ENABLED
                        if ( opengl ) {
                            selection = new slop::GLSelectRectangle( t.m_x, t.m_y,
                                                                     t.m_x + t.m_width,
                                                                     t.m_y + t.m_height,
                                                                     borderSize,
                                                                     highlight,
                                                                     r, g, b, a );
                            // Haha why is this so hard to cast?
                            ((slop::GLSelectRectangle*)(selection))->setMagnifySettings( magenabled, magstrength, magpixels );
                            ((slop::GLSelectRectangle*)(selection))->setTheme( themeon, theme );
                            ((slop::GLSelectRectangle*)(selection))->setShader( shader );
                        } else {
#endif // OPENGL_ENABLED
                            selection = new slop::XSelectRectangle( t.m_x, t.m_y,
                                                                    t.m_x + t.m_width,
                                                                    t.m_y + t.m_height,
                                                                    borderSize,
                                                                    highlight,
                                                                    r, g, b, a );
#ifdef OPENGL_ENABLED
                        }
#endif // OPENGL_ENABLED
                    } else {
                        selection->setGeo( t.m_x, t.m_y, t.m_x + t.m_width, t.m_y + t.m_height );
                    }
                    //window = xengine->m_hoverWindow;
                    // Since WindowRectangle can select different windows depending on click location...
                    window = t.getWindow();
                }
                if ( selection ) {
                    selection->update( deltatime );
                }
                // If the user clicked we move on to the next state.
                if ( xengine->mouseDown( 1 ) ) {
                    state++;
                }
                break;
            }
            case 1: {
                // Set the mouse position of where we clicked, used so that click tolerance doesn't affect the rectangle's position.
                cx = xengine->m_mousex;
                cy = xengine->m_mousey;
                // Make sure we don't have un-seen applied offsets.
                xoffset = 0;
                yoffset = 0;
                // Also remember where the original selection was
                if ( selection ) {
                    xmem = selection->m_x;
                    ymem = selection->m_y;
                    wmem = selection->m_width;
                    hmem = selection->m_height;
                } else {
                    xmem = cx;
                    ymem = cy;
                }
                state++;
                break;
            }
            case 2: {
                // It's possible that our selection doesn't exist still, lets make sure it actually gets created here.
                if ( !selection ) {
                    int sx, sy, ex, ey;
                    constrain( cx, cy, xengine->m_mousex, xengine->m_mousey, padding, minimumsize, maximumsize, &sx, &sy, &ex, &ey );
#ifdef OPENGL_ENABLED
                    if ( opengl ) {
                        selection = new slop::GLSelectRectangle( sx, sy,
                                                                 ex, ey,
                                                                 borderSize,
                                                                 highlight,
                                                                 r, g, b, a );
                        // Haha why is this so hard to cast?
                        ((slop::GLSelectRectangle*)(selection))->setMagnifySettings( magenabled, magstrength, magpixels );
                        ((slop::GLSelectRectangle*)(selection))->setTheme( themeon, theme );
                        ((slop::GLSelectRectangle*)(selection))->setShader( shader );
                    } else {
#endif // OPENGL_ENABLED
                        selection = new slop::XSelectRectangle( sx, sy,
                                                                ex, ey,
                                                                borderSize,
                                                                highlight,
                                                                r, g, b, a );
#ifdef OPENGL_ENABLED
                    }
#endif // OPENGL_ENABLED
                }
                windowmemory = window;
                // If the user has let go of the mouse button, we'll just
                // continue to the next state.
                if ( !xengine->mouseDown( 1 ) ) {
                    state++;
                    break;
                }
                // Check to make sure the user actually wants to drag for a selection before moving things around.
                int w = xengine->m_mousex - cx;
                int h = xengine->m_mousey - cy;
                if ( ( std::abs( w ) < tolerance && std::abs( h ) < tolerance ) ) {
                    // We make sure the selection rectangle stays on the window we had selected
                    selection->setGeo( xmem, ymem, xmem + wmem, ymem + hmem );
                    selection->update( deltatime );
                    xengine->setCursor( slop::Left );
                    // Make sure
                    window = windowmemory;
                    continue;
                }
                // If we're not selecting a window.
                windowmemory = window;
                window = None;
                // We also detect which way the user is pulling and set the mouse icon accordingly.
                bool x = cx > xengine->m_mousex;
                bool y = cy > xengine->m_mousey;
                if ( ( selection->m_width <= 1 && selection->m_height <= 1 ) || ( minimumsize == maximumsize && minimumsize != 0 && maximumsize != 0 ) ) {
                    xengine->setCursor( slop::Cross );
                } else if ( !x && !y ) {
                    xengine->setCursor( slop::LowerRightCorner );
                } else if ( x && !y ) {
                    xengine->setCursor( slop::LowerLeftCorner );
                } else if ( !x && y ) {
                    xengine->setCursor( slop::UpperRightCorner );
                } else if ( x && y ) {
                    xengine->setCursor( slop::UpperLeftCorner );
                }
                // Apply padding and minimum size adjustments.
                int sx, sy, ex, ey;
                constrain( cx, cy, xengine->m_mousex, xengine->m_mousey, padding, minimumsize, maximumsize, &sx, &sy, &ex, &ey );
                // Set the selection rectangle's dimensions to mouse movement.
                selection->setGeo( sx + xoffset, sy + yoffset, ex-1, ey-1 );
                selection->update( deltatime );
                break;
            }
            case 3: {
                int x, y, w, h;
                // Exit the utility after this state runs once.
                running = false;
                // We pull the dimensions and positions from the selection rectangle.
                // The selection rectangle automatically converts the positions and
                // dimensions to absolute coordinates when we set them earilier.
                x = selection->m_x;
                y = selection->m_y;
                w = selection->m_width;
                h = selection->m_height;
                // Delete the rectangle, which will remove it from the screen.
                delete selection;
                // Make sure if no window was specifically specified, that we output the root window.
                Window temp = window;
                if ( temp == None ) {
                    temp = xengine->m_root;
                }
                // Print the selection :)
                printSelection( format, false, x, y, w, h, temp );
                break;
            }
        }
        // This sleep is required because drawing the rectangles is a very expensive task that acts really weird with Xorg when called as fast as possible.
        // 0.01 seconds
        usleep( 10000 );
    }
    xengine->releaseCursor();
    xengine->releaseKeyboard();
    // Try to process any last-second requests.
    //xengine->tick();
    // Clean up global classes.
    delete xengine;
    // Sleep for 0.05 seconds to ensure everything was cleaned up. (Without this, slop's window often shows up in screenshots.)
    usleep( 50000 );
    // If we canceled the selection, return error.
    if ( state == -1 ) {
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}

int main( int argc, char** argv ) {
    try {
        return app( argc, argv );
    } catch( std::bad_alloc const& exception ) {
        fprintf( stderr, "Couldn't allocate enough memory! No space left in RAM." );
    } catch( std::exception const& exception ) {
        fprintf( stderr, "Unhandled Exception Thrown: %s\n", exception.what() );
    } catch( std::string err ) {
        fprintf( stderr, "Unhandled Exception Thrown: %s\n", err.c_str() );
    } catch( char* err ) {
        fprintf( stderr, "Unhandled Exception Thrown: %s\n", err );
    } catch( ... ) {
        fprintf( stderr, "Unknown Exception Thrown!\n" );
    }
    return EXIT_FAILURE;
}