/*
 * tasklist.c - task list widget
 *
 * Copyright © 2008 Julien Danjou <julien@danjou.info>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include "client.h"
#include "widget.h"
#include "ewmh.h"
#include "tag.h"
#include "common/markup.h"
#include "common/tokenize.h"

extern awesome_t globalconf;

/** Link a client and a label */
typedef struct
{
    /** A client */
    client_t *client;
    /** The client label */
    char *label;
    /** The client label len */
    size_t label_len;
} client_label_t;

/** Delete a client label.
 * \param l The client label.
 */
static void
client_label_wipe(client_label_t *l)
{
    p_delete(&l->label);
}

DO_ARRAY(client_label_t, client_label, client_label_wipe)

typedef struct tasklist_object_data_t tasklist_object_data_t;
/** Link an object with a client label array and other infos */
struct tasklist_object_data_t
{
    /** The object */
    void *object;
    /** The box width for each client */
    int box_width;
    /** The client label array for the object */
    client_label_array_t client_labels;
    /** This is a list */
    tasklist_object_data_t *prev, *next;
};

static void
tasklist_object_data_delete(tasklist_object_data_t **l)
{
    client_label_array_wipe(&(*l)->client_labels);
    p_delete(l);
}

DO_SLIST(tasklist_object_data_t, tasklist_object_data, tasklist_object_data_delete)

/** The tasklist private data structure. */
typedef struct
{
    bool show_icons;
    luaA_ref label;
    tasklist_object_data_t *objects_data;
    bool invert;
} tasklist_data_t;

/** Get an object data by its object.
 * \param od The object data list.
 * \param p The object.
 * \return A object data or NULL if not found.
 */
static tasklist_object_data_t *
tasklist_object_data_getbyobj(tasklist_object_data_t *od, void *p)
{
    tasklist_object_data_t *o;

    for(o = od; o; o = o->next)
        if(o->object == p)
            return o;

    return NULL;
}

/** Draw an item in a tasklist widget.
 * \param ctx The draw context, must be the same used to draw the tasklist
 * \param w Tasklist widget node
 * \param odata Tasklist object data
 * \param width_mod Width modification of the item
 * \param pos Position to draw the item at
 * \param i Item to draw
 */
static void
tasklist_draw_item(draw_context_t *ctx,
                   widget_node_t *w,
                   tasklist_object_data_t *odata,
                   int width_mod, int pos, int i) {
    draw_parser_data_t pdata, *parser_data;
    draw_image_t *image;
    area_t area;
    tasklist_data_t *d = w->widget->data;
    int icon_width = 0;

    if(d->show_icons)
    {
        draw_parser_data_init(&pdata);

        pdata.connection = ctx->connection;
        pdata.phys_screen = ctx->phys_screen;

        /* Actually look for the proper background color, since
         * otherwise the background statusbar color is used instead */
        if(draw_text_markup_expand(&pdata,
                                   odata->client_labels.tab[i].label,
                                   odata->client_labels.tab[i].label_len))
        {
            parser_data = &pdata;
            if(pdata.has_bg_color)
            {
                /* draw a background for icons */
                area.x = w->area.x + pos;
                area.y = w->area.y;
                area.height = ctx->height;
                area.width = odata->box_width;
                draw_rectangle(ctx, area, 1.0, true, &pdata.bg_color);
            }
        }
        else
            parser_data = NULL;

        if((image = draw_image_new(odata->client_labels.tab[i].client->icon_path)))
        {
            icon_width = ((double) ctx->height / (double) image->height) * image->width;
            draw_image(ctx, w->area.x + pos,
                       w->area.y, ctx->height, image);
            draw_image_delete(&image);
        }

        if(!icon_width && odata->client_labels.tab[i].client->icon)
        {
            netwm_icon_t *icon = odata->client_labels.tab[i].client->icon;
            icon_width = ((double) ctx->height / (double) icon->height)
                * icon->width;
            draw_image_from_argb_data(ctx,
                                      w->area.x + pos,
                                      w->area.y,
                                      icon->width, icon->height,
                                      ctx->height, icon->image);
        }
    }
    else
        parser_data = NULL;

    area.x = w->area.x + icon_width + pos;
    area.y = w->area.y;
    area.width = odata->box_width - icon_width + width_mod;
    area.height = ctx->height;

    draw_text(ctx, globalconf.font, area,
              odata->client_labels.tab[i].label,
              odata->client_labels.tab[i].label_len,
              parser_data);
    draw_parser_data_wipe(parser_data);
}

/** Draw a tasklist widget.
 * \param ctx The draw context.
 * \param screen The screen number.
 * \param w The widget node we are called from.
 * \param offset The offset to draw at.
 * \param used The already used width.
 * \param p A pointer to the object we're drawing onto.
 * \param type The object type.
 * \return The widget width.
 */
static int
tasklist_draw(draw_context_t *ctx, int screen,
              widget_node_t *w,
              int offset, int used, void *p,
              awesome_type_t type)
{
    client_t *c;
    tasklist_data_t *d = w->widget->data;
    int i = 0, box_width_rest = 0, pos = 0;
    tasklist_object_data_t *odata;

    if(used >= ctx->width)
        return (w->area.width = 0);

    if(!(odata = tasklist_object_data_getbyobj(d->objects_data, p)))
    {
        odata = p_new(tasklist_object_data_t, 1);
        odata->object = p;
        tasklist_object_data_list_push(&d->objects_data, odata);
    }

    client_label_array_wipe(&odata->client_labels);
    client_label_array_init(&odata->client_labels);

    for(c = globalconf.clients; c; c = c->next)
        if(!c->skip && !c->skiptb)
        {
            /* push client */
            luaA_client_userdata_new(globalconf.L, c);
            /* push screen we're at */
            lua_pushnumber(globalconf.L, screen + 1);
            /* call label function with client as argument and wait for one
             * result */
            if(luaA_dofunction(globalconf.L, d->label, 2, 1))
            {
                /* If we got a string as returned value, we got something to write:
                 * a label. So we store it in a client_label_t structure, pushed
                 * into the client_label_array_t which is owned by the object. */
                if(lua_isstring(globalconf.L, -1))
                {
                    client_label_t cl;
                    cl.client = c;
                    cl.label = a_strdup(lua_tolstring(globalconf.L, -1, &cl.label_len));
                    client_label_array_append(&odata->client_labels, cl);
                }

                lua_pop(globalconf.L, 1);
            }
        }

    if(!odata->client_labels.len)
        return (w->area.width = 0);

    odata->box_width = (ctx->width - used) / odata->client_labels.len;
    /* compute how many pixel we left empty */
    box_width_rest = (ctx->width - used) % odata->client_labels.len;

    w->area.x = widget_calculate_offset(ctx->width,
                                        0, offset, w->widget->align);

    w->area.y = 0;

    if(d->invert)
        for(i = odata->client_labels.len - 1; i >= 0; i--)
        {
            /* if we're on last elem, it has the last pixels left. */
            if (i == 0)
                tasklist_draw_item(ctx, w, odata, 0, pos, i);
            else
                tasklist_draw_item(ctx, w, odata, box_width_rest, pos, i);
            pos += odata->box_width;
        }
    else
        for(i = 0; i < odata->client_labels.len; i++)
        {
            /* if we're on last elem, it has the last pixels left. */
            if(i != odata->client_labels.len - 1)
                tasklist_draw_item(ctx, w, odata, 0, pos , i);
            else
                tasklist_draw_item(ctx, w, odata, box_width_rest, pos, i);
            pos += odata->box_width;
        }

    w->area.width = ctx->width - used;
    w->area.height = ctx->height;

    return w->area.width;
}

/** Handle button click on tasklist.
 * \param w The widget node.
 * \param ev The button press event.
 * \param screen The screen where the click was.
 * \param object The object we're onto.
 * \param type The type object.
 */
static void
tasklist_button(widget_node_t *w,
                xcb_button_press_event_t *ev,
                int screen,
                void *object,
                awesome_type_t type)
{
    tasklist_data_t *d = w->widget->data;
    int ci = 0;
    tasklist_object_data_t *odata;
    button_array_t *barr = &w->widget->buttons;

    odata = tasklist_object_data_getbyobj(d->objects_data, object);

    if(!odata || !odata->client_labels.len)
        return;

    if (!d->invert)
        ci = (ev->event_x - w->area.x) / odata->box_width;
    else
        ci = odata->client_labels.len - 1 - (ev->event_x - w->area.x) / odata->box_width;

    for(int i = 0; i < barr->len; i++)
        if(ev->detail == barr->tab[i]->button
           && XUTIL_MASK_CLEAN(ev->state) == barr->tab[i]->mod)
        {
            luaA_pushpointer(globalconf.L, object, type);
            luaA_client_userdata_new(globalconf.L, odata->client_labels.tab[ci].client);
            luaA_dofunction(globalconf.L,
                            ev->response_type == XCB_BUTTON_PRESS ?
                            barr->tab[i]->press : barr->tab[i]->release,
                            2, 0);
        }
}

/** Tasklist widget.
 * \param L The Lua VM state.
 * \param token The key token.
 * \return The number of elements pushed on stack.
 * \luastack
 * \lfield show_icons Show icons near client title.
 * \lfield label Function used to get the string to display as the window title.
 * It gets the client and a screen number as argument, and must return a string.
 */
static int
luaA_tasklist_index(lua_State *L, awesome_token_t token)
{
    widget_t **widget = luaA_checkudata(L, 1, "widget");
    tasklist_data_t *d = (*widget)->data;

    switch(token)
    {
      case A_TK_SHOW_ICONS:
        lua_pushboolean(L, d->show_icons);
        return 1;
      case A_TK_LABEL:
        lua_rawgeti(L, LUA_REGISTRYINDEX, d->label);
        return 1;
      case A_TK_INVERT:
        lua_pushboolean(L, d->invert);
        return 1;
      default:
        return 0;
    }
}

/** Newindex function for tasklist widget.
 * \param L The Lua VM state.
 * \param token The key token.
 * \return The number of elements pushed on stack.
 */
static int
luaA_tasklist_newindex(lua_State *L, awesome_token_t token)
{
    widget_t **widget = luaA_checkudata(L, 1, "widget");
    tasklist_data_t *d = (*widget)->data;

    switch(token)
    {
      case A_TK_SHOW_ICONS:
        d->show_icons = luaA_checkboolean(L, 3);
        break;
      case A_TK_LABEL:
        luaA_registerfct(L, 3, &d->label);
        break;
      case A_TK_INVERT:
        d->invert = luaA_checkboolean(L, 3);
        break;
      default:
        return 0;
    }

    widget_invalidate_bywidget(*widget);

    return 0;
}

/** Destructor for the tasklist widget.
 * \param widget The widget to destroy.
 */
static void
tasklist_destructor(widget_t *widget)
{
    tasklist_data_t *d = widget->data;
    tasklist_object_data_list_wipe(&d->objects_data);
    p_delete(&d);
}

/** Tasklist detach function.
 * \param widget The widget which is detaching.
 * \param object The object we are leaving.
 */
static void
tasklist_detach(widget_t *widget, void *object)
{
    tasklist_data_t *d = widget->data;
    tasklist_object_data_t *od;

    if((od = tasklist_object_data_getbyobj(d->objects_data, object)))
    {
        tasklist_object_data_list_detach(&d->objects_data, od);
        tasklist_object_data_delete(&od);
    }
}

/** Create a new widget tasklist.
 * \param align The widget alignment, which is flex anyway.
 * \return A brand new tasklist widget.
 */
widget_t *
tasklist_new(alignment_t align __attribute__ ((unused)))
{
    widget_t *w;
    tasklist_data_t *d;

    w = p_new(widget_t, 1);
    widget_common_new(w);
    w->draw = tasklist_draw;
    w->button = tasklist_button;
    w->align = AlignFlex;
    w->index = luaA_tasklist_index;
    w->newindex = luaA_tasklist_newindex;
    w->data = d = p_new(tasklist_data_t, 1);
    w->destructor = tasklist_destructor;
    w->detach = tasklist_detach;

    d->show_icons = true;
    d->label = LUA_REFNIL;
    d->invert = false;

    /* Set cache property */
    w->cache_flags = WIDGET_CACHE_CLIENTS | WIDGET_CACHE_TAGS;

    return w;
}

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