/*
 * vim:ts=8:expandtab
 *
 * i3 - an improved dynamic tiling window manager
 *
 * © 2009 Michael Stapelberg and contributors
 *
 * See file LICENSE for license information.
 *
 */
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdbool.h>
#include <assert.h>
#include <limits.h>

#include <xcb/xcb.h>

#include <X11/XKBlib.h>
#include <X11/extensions/XKB.h>

#include <xcb/xcb_wm.h>
#include <xcb/xcb_aux.h>
#include <xcb/xcb_event.h>
#include <xcb/xcb_property.h>
#include <xcb/xcb_keysyms.h>
#include <xcb/xcb_icccm.h>
#include <xcb/xinerama.h>
#include "data.h"

#include "queue.h"
#include "table.h"
#include "font.h"
#include "layout.h"
#include "debug.h"
#include "handlers.h"
#include "util.h"
#include "xcb.h"
#include "xinerama.h"

#define TERMINAL "/usr/pkg/bin/urxvt"

Display *xkbdpy;

TAILQ_HEAD(bindings_head, Binding) bindings = TAILQ_HEAD_INITIALIZER(bindings);
xcb_event_handlers_t evenths;

xcb_window_t root_win;
xcb_atom_t atoms[6];


char *pattern = "-misc-fixed-medium-r-normal--13-120-75-75-C-70-iso8859-1";
int num_screens = 0;

/*
 *
 * TODO: what exactly does this, what happens if we leave stuff out?
 *
 */
void manage_window(xcb_property_handlers_t *prophs, xcb_connection_t *c, xcb_window_t window, window_attributes_t wa)
{
        printf("managing window.\n");
        xcb_drawable_t d = { window };
        xcb_get_geometry_cookie_t geomc;
        xcb_get_geometry_reply_t *geom;
        xcb_get_window_attributes_reply_t *attr = 0;
        if(wa.tag == TAG_COOKIE)
        {
                attr = xcb_get_window_attributes_reply(c, wa.u.cookie, 0);
                if(!attr)
                        return;
                if(attr->map_state != XCB_MAP_STATE_VIEWABLE)
                {
                        printf("Window 0x%08x is not mapped. Ignoring.\n", window);
                        free(attr);
                        return;
                }
                wa.tag = TAG_VALUE;
                wa.u.override_redirect = attr->override_redirect;
        }
        if(!wa.u.override_redirect && table_get(byChild, window))
        {
                printf("Window 0x%08x already managed. Ignoring.\n", window);
                free(attr);
                return;
        }
        if(wa.u.override_redirect)
        {
                printf("Window 0x%08x has override-redirect set. Ignoring.\n", window);
                free(attr);
                return;
        }
        geomc = xcb_get_geometry(c, d);
        if(!attr)
        {
                wa.tag = TAG_COOKIE;
                wa.u.cookie = xcb_get_window_attributes(c, window);
                attr = xcb_get_window_attributes_reply(c, wa.u.cookie, 0);
        }
        geom = xcb_get_geometry_reply(c, geomc, 0);
        if(attr && geom)
        {
                reparent_window(c, window, attr->visual, geom->root, geom->depth, geom->x, geom->y, geom->width, geom->height);
                xcb_property_changed(prophs, XCB_PROPERTY_NEW_VALUE, window, WM_NAME);
        }
        free(attr);
        free(geom);
}

/*
 * reparent_window() gets called when a new window was opened and becomes a child of the root
 * window, or it gets called by us when we manage the already existing windows at startup.
 *
 * Essentially, this is the point, where we take over control.
 *
 */
void reparent_window(xcb_connection_t *conn, xcb_window_t child,
                xcb_visualid_t visual, xcb_window_t root, uint8_t depth,
                int16_t x, int16_t y, uint16_t width, uint16_t height) {

        Client *new = table_get(byChild, child);
        if (new == NULL) {
                /* TODO: When does this happen for existing clients? Is that a bug? */
                printf("oh, it's new\n");
                new = calloc(sizeof(Client), 1);
                /* We initialize x and y with the invalid coordinates -1 so that they will
                   get updated at the next render_layout() at any case */
                new->rect.x = -1;
                new->rect.y = -1;
        }
        uint32_t mask = 0;
        uint32_t values[3];

        /* Insert into the currently active container */
        CIRCLEQ_INSERT_TAIL(&(CUR_CELL->clients), new, clients);

        /* Update the data structures */
        CUR_CELL->currently_focused = new;
        new->container = CUR_CELL;

        new->frame = xcb_generate_id(conn);
        new->child = child;
        new->rect.width = width;
        new->rect.height = height;

        /* Don’t generate events for our new window, it should *not* be managed */
        mask |= XCB_CW_OVERRIDE_REDIRECT;
        values[0] = 1;

        /* We want to know when… */
        mask |= XCB_CW_EVENT_MASK;
        values[1] =     XCB_EVENT_MASK_BUTTON_PRESS |   /* …mouse is pressed/released */
                        XCB_EVENT_MASK_BUTTON_RELEASE |
                        XCB_EVENT_MASK_EXPOSURE |       /* …our window needs to be redrawn */
                        XCB_EVENT_MASK_ENTER_WINDOW;    /* …user moves cursor inside our window */

        printf("Reparenting 0x%08x under 0x%08x.\n", child, new->frame);

        i3Font *font = load_font(conn, pattern);
        width = min(width, c_ws->rect.x + c_ws->rect.width);
        height = min(height, c_ws->rect.y + c_ws->rect.height);

        Rect framerect = {x, y,
                          width + 2 + 2,                  /* 2 px border at each side */
                          height + 2 + 2 + font->height}; /* 2 px border plus font’s height */

        /* Yo dawg, I heard you like windows, so I create a window around your window… */
        new->frame = create_window(conn, framerect, XCB_WINDOW_CLASS_INPUT_OUTPUT, mask, values);

        /* TODO: document */
        xcb_change_save_set(conn, XCB_SET_MODE_INSERT, child);

        /* Generate a graphics context for the titlebar */
        new->titlegc = xcb_generate_id(conn);
        xcb_create_gc(conn, new->titlegc, new->frame, 0, 0);

        /* Put our data structure (Client) into the table */
        table_put(byParent, new->frame, new);
        table_put(byChild, child, new);

        /* Moves the original window into the new frame we've created for it */
        new->awaiting_useless_unmap = true;
        xcb_void_cookie_t cookie = xcb_reparent_window_checked(conn, child, new->frame, 0, font->height);
        check_error(conn, cookie, "Could not reparent window");

        /* We are interested in property changes */
        mask = XCB_CW_EVENT_MASK;
        values[0] =     XCB_EVENT_MASK_PROPERTY_CHANGE |
                        XCB_EVENT_MASK_STRUCTURE_NOTIFY |
                        XCB_EVENT_MASK_ENTER_WINDOW;
        cookie = xcb_change_window_attributes_checked(conn, child, mask, values);
        check_error(conn, cookie, "Could not change window attributes");

        /* We need to grab the mouse buttons for click to focus */
        xcb_grab_button(conn, false, child, XCB_EVENT_MASK_BUTTON_PRESS,
                        XCB_GRAB_MODE_ASYNC, XCB_GRAB_MODE_ASYNC, root, XCB_NONE,
                        1 /* left mouse button */,
                        XCB_BUTTON_MASK_ANY /* don’t filter for any modifiers */);

        /* Focus the new window */
        xcb_set_input_focus(conn, XCB_INPUT_FOCUS_POINTER_ROOT, new->child, XCB_CURRENT_TIME);

        render_layout(conn);
}

void manage_existing_windows(xcb_connection_t *c, xcb_property_handlers_t *prophs, xcb_window_t root) {
        xcb_query_tree_cookie_t wintree;
        xcb_query_tree_reply_t *rep;
        int i, len;
        xcb_window_t *children;
        xcb_get_window_attributes_cookie_t *cookies;

        wintree = xcb_query_tree(c, root);
        rep = xcb_query_tree_reply(c, wintree, 0);
        if(!rep)
                return;
        len = xcb_query_tree_children_length(rep);
        cookies = malloc(len * sizeof(*cookies));
        if(!cookies)
        {
                free(rep);
                return;
        }
        children = xcb_query_tree_children(rep);
        for(i = 0; i < len; ++i)
                cookies[i] = xcb_get_window_attributes(c, children[i]);
        for(i = 0; i < len; ++i)
        {
                window_attributes_t wa = { TAG_COOKIE, { cookies[i] } };
                manage_window(prophs, c, children[i], wa);
        }
        free(rep);
}

int main(int argc, char *argv[], char *env[]) {
        int i, screens;
        xcb_connection_t *c;
        xcb_property_handlers_t prophs;
        xcb_window_t root;

        /* Initialize the table data structures for each workspace */
        init_table();

        memset(&evenths, 0, sizeof(xcb_event_handlers_t));
        memset(&prophs, 0, sizeof(xcb_property_handlers_t));

        byChild = alloc_table();
        byParent = alloc_table();

        c = xcb_connect(NULL, &screens);

        /* TODO: this has to be more beautiful somewhen */
        int major, minor, error;

        major = XkbMajorVersion;
        minor = XkbMinorVersion;

        int evBase, errBase;

        if ((xkbdpy = XkbOpenDisplay(getenv("DISPLAY"), &evBase, &errBase, &major, &minor, &error)) == NULL) {
                fprintf(stderr, "XkbOpenDisplay() failed\n");
                return 1;
        }

        int i1;
        if (!XkbQueryExtension(xkbdpy,&i1,&evBase,&errBase,&major,&minor)) {
                fprintf(stderr, "XKB not supported by X-server\n");
                return 1;
        }
        /* end of ugliness */

        xcb_event_handlers_init(c, &evenths);
        for(i = 2; i < 128; ++i)
                xcb_event_set_handler(&evenths, i, handle_event, 0);

        for(i = 0; i < 256; ++i)
                xcb_event_set_error_handler(&evenths, i, (xcb_generic_error_handler_t)handle_event, 0);

        /* Expose = an Application should redraw itself. That is, we have to redraw our
         * contents (= top/bottom bar, titlebars for each window) */
        xcb_event_set_expose_handler(&evenths, handle_expose_event, 0);

        /* Key presses/releases are pretty obvious, I think */
        xcb_event_set_key_press_handler(&evenths, handle_key_press, 0);
        xcb_event_set_key_release_handler(&evenths, handle_key_release, 0);

        /* Enter window = user moved his mouse over the window */
        xcb_event_set_enter_notify_handler(&evenths, handle_enter_notify, 0);

        /* Button press = user pushed a mouse button over one of our windows */
        xcb_event_set_button_press_handler(&evenths, handle_button_press, 0);

        xcb_event_set_unmap_notify_handler(&evenths, handle_unmap_notify_event, 0);

        xcb_property_handlers_init(&prophs, &evenths);
        xcb_event_set_map_notify_handler(&evenths, handle_map_notify_event, &prophs);

        xcb_event_set_client_message_handler(&evenths, handle_client_message, 0);

        xcb_watch_wm_name(&prophs, 128, handle_windowname_change, 0);

        root = xcb_aux_get_screen(c, screens)->root;
        root_win = root;

        uint32_t mask = XCB_CW_EVENT_MASK;
        uint32_t values[] = { XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_PROPERTY_CHANGE | XCB_EVENT_MASK_ENTER_WINDOW};
        xcb_change_window_attributes(c, root, mask, values);

        /* Setup NetWM atoms */
        /* TODO: needs cleanup, needs more xcb (asynchronous), needs more error checking */
#define GET_ATOM(name) { \
        xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply(c, xcb_intern_atom(c, 0, strlen(#name), #name), NULL); \
        if (!reply) { \
                printf("Could not get atom " #name "\n"); \
                exit(-1); \
        } \
        atoms[name] = reply->atom; \
        free(reply); \
}

        GET_ATOM(_NET_SUPPORTED);
        GET_ATOM(_NET_WM_STATE_FULLSCREEN);
        GET_ATOM(_NET_SUPPORTING_WM_CHECK);
        GET_ATOM(_NET_WM_NAME);
        GET_ATOM(UTF8_STRING);
        GET_ATOM(_NET_WM_STATE);

        check_error(c, xcb_change_property_checked(c, XCB_PROP_MODE_REPLACE, root, atoms[_NET_SUPPORTED], ATOM, 32, 5, atoms), "Could not set _NET_SUPPORTED");

        xcb_change_property(c, XCB_PROP_MODE_REPLACE, root, atoms[_NET_SUPPORTING_WM_CHECK], WINDOW, 32, 1, &root);

        xcb_change_property(c, XCB_PROP_MODE_REPLACE, root, atoms[_NET_WM_NAME] , atoms[UTF8_STRING], 8, strlen("i3"), "i3");

        #define BIND(key, modifier, cmd) { \
                Binding *new = malloc(sizeof(Binding)); \
                new->keycode = key; \
                new->mods = modifier; \
                new->command = cmd; \
                TAILQ_INSERT_TAIL(&bindings, new, bindings); \
        }

        /* 38 = 'a' */
        BIND(38, BIND_MODE_SWITCH, "foo");

        BIND(30, 0, "exec /usr/pkg/bin/urxvt");

        BIND(41, BIND_MOD_1, "f");

        BIND(44, BIND_MOD_1, "h");
        BIND(45, BIND_MOD_1, "j");
        BIND(46, BIND_MOD_1, "k");
        BIND(47, BIND_MOD_1, "l");

        BIND(44, BIND_MOD_1 | BIND_CONTROL, "sh");
        BIND(45, BIND_MOD_1 | BIND_CONTROL, "sj");
        BIND(46, BIND_MOD_1 | BIND_CONTROL, "sk");
        BIND(47, BIND_MOD_1 | BIND_CONTROL, "sl");

        BIND(44, BIND_MOD_1 | BIND_SHIFT, "mh");
        BIND(45, BIND_MOD_1 | BIND_SHIFT, "mj");
        BIND(46, BIND_MOD_1 | BIND_SHIFT, "mk");
        BIND(47, BIND_MOD_1 | BIND_SHIFT, "ml");

        BIND(10, BIND_MOD_1 , "1");
        BIND(11, BIND_MOD_1 , "2");
        BIND(12, BIND_MOD_1 , "3");
        BIND(13, BIND_MOD_1 , "4");
        BIND(14, BIND_MOD_1 , "5");
        BIND(15, BIND_MOD_1 , "6");
        BIND(16, BIND_MOD_1 , "7");
        BIND(17, BIND_MOD_1 , "8");
        BIND(18, BIND_MOD_1 , "9");
        BIND(19, BIND_MOD_1 , "0");

        Binding *bind;
        TAILQ_FOREACH(bind, &bindings, bindings) {
                printf("Grabbing %d\n", bind->keycode);
                if (bind->mods & BIND_MODE_SWITCH)
                        xcb_grab_key(c, 0, root, 0, bind->keycode, XCB_GRAB_MODE_SYNC, XCB_GRAB_MODE_SYNC);
                else xcb_grab_key(c, 0, root, bind->mods, bind->keycode, XCB_GRAB_MODE_SYNC, XCB_GRAB_MODE_ASYNC);
        }

        /* check for Xinerama */
        printf("Checking for Xinerama...\n");
        initialize_xinerama(c);

        start_application(TERMINAL);

        xcb_flush(c);

        manage_existing_windows(c, &prophs, root);

        /* Get pointer position to see on which screen we’re starting */
        xcb_query_pointer_cookie_t pointer_cookie = xcb_query_pointer(c, root);
        xcb_query_pointer_reply_t *reply = xcb_query_pointer_reply(c, pointer_cookie, NULL);
        if (reply == NULL) {
                printf("Could not get pointer position\n");
                return 1;
        }

        i3Screen *screen = get_screen_containing(reply->root_x, reply->root_y);
        if (screen == NULL) {
                printf("ERROR: No such screen\n");
                return 0;
        }
        if (screen->current_workspace != 0) {
                printf("Ok, I need to go to the other workspace\n");
                c_ws = &workspaces[screen->current_workspace];
        }

        xcb_event_wait_for_event_loop(&evenths);

        /* not reached */
        return 0;
}