#include "wm.h"

#define SWL_ITEM_W   130
#define SWL_ITEM_H    68
#define SWL_ICON_SZ   34
#define SWL_PAD       12
#define SWL_MAX_VIS    8

static void swl_populate(WM *wm) {
    wm->swl_count = 0;
    /* current focused (non-minimized) window goes first */
    if (wm->focused && !wm->focused->minimized) {
        wm->swl_wins[0]   = wm->focused->win;
        wm->swl_mini[0]   = 0;
        strncpy(wm->swl_titles[0], wm->focused->title, 127);
        wm->swl_titles[0][127] = '\0';
        wm->swl_count = 1;
    }
    /* all other windows, including minimized ones */
    for (Client *c = wm->clients; c && wm->swl_count < 64; c = c->next) {
        if (wm->focused && c == wm->focused) continue;
        wm->swl_wins[wm->swl_count]   = c->win;
        wm->swl_mini[wm->swl_count]   = c->minimized;
        strncpy(wm->swl_titles[wm->swl_count], c->title, 127);
        wm->swl_titles[wm->swl_count][127] = '\0';
        wm->swl_count++;
    }
}

static int swl_vis(WM *wm) {
    return wm->swl_count < SWL_MAX_VIS ? wm->swl_count : SWL_MAX_VIS;
}

/* Scroll window that keeps the selected item centered */
static int swl_view_start(WM *wm) {
    int vis = swl_vis(wm);
    if (wm->swl_count <= SWL_MAX_VIS) return 0;
    int start = wm->swl_idx - vis / 2;
    if (start < 0) start = 0;
    if (start + vis > wm->swl_count) start = wm->swl_count - vis;
    return start;
}

void switcher_draw(WM *wm) {
    if (!wm->swl_visible || !wm->swl_win) return;

    int vis    = swl_vis(wm);
    int vstart = swl_view_start(wm);
    int tw     = vis * SWL_ITEM_W + (vis + 1) * SWL_PAD;
    int th     = SWL_ITEM_H + SWL_PAD * 2;

    XSetForeground(wm->dpy, wm->gc, color_alloc(wm, 0x141A28));
    XFillRectangle(wm->dpy, wm->swl_win, wm->gc, 0, 0, tw, th);

    XSetForeground(wm->dpy, wm->gc, color_alloc(wm, COLOR_BORDER_LIGHT));
    XDrawRectangle(wm->dpy, wm->swl_win, wm->gc, 0, 0, tw - 1, th - 1);
    XSetForeground(wm->dpy, wm->gc, color_alloc(wm, COLOR_BORDER_DARK));
    XDrawRectangle(wm->dpy, wm->swl_win, wm->gc, 1, 1, tw - 3, th - 3);

    XftDraw *xd = XftDrawCreate(wm->dpy, wm->swl_win, wm->visual, wm->cmap);
    if (!xd) return;

    for (int vi = 0; vi < vis; vi++) {
        int i        = vstart + vi;
        int selected = (i == wm->swl_idx);
        int mini     = wm->swl_mini[i];
        int ix       = SWL_PAD + vi * (SWL_ITEM_W + SWL_PAD);
        int iy       = SWL_PAD;

        unsigned long card_bg = color_alloc(wm,
            selected ? COLOR_TITLE_ACTIVE : (mini ? 0x141820 : 0x1C2338));
        XSetForeground(wm->dpy, wm->gc, card_bg);
        XFillRectangle(wm->dpy, wm->swl_win, wm->gc, ix, iy, SWL_ITEM_W, SWL_ITEM_H);

        XSetForeground(wm->dpy, wm->gc,
            color_alloc(wm, selected ? COLOR_BORDER_LIGHT : (mini ? 0x202028 : 0x242C3E)));
        XDrawRectangle(wm->dpy, wm->swl_win, wm->gc, ix, iy, SWL_ITEM_W - 1, SWL_ITEM_H - 1);

        /* letter icon — dimmed for minimized */
        int icon_x = ix + (SWL_ITEM_W - SWL_ICON_SZ) / 2;
        int icon_y = iy + 8;
        XSetForeground(wm->dpy, wm->gc,
            color_alloc(wm, selected ? 0x285898 : (mini ? 0x1A1E28 : 0x182538)));
        XFillRectangle(wm->dpy, wm->swl_win, wm->gc, icon_x, icon_y, SWL_ICON_SZ, SWL_ICON_SZ);

        char letter[2] = { wm->swl_titles[i][0] ? wm->swl_titles[i][0] : '?', '\0' };
        if (letter[0] >= 'a' && letter[0] <= 'z') letter[0] -= 32;

        unsigned long icon_rgb = selected ? COLOR_TITLE_TEXT_ACT
                               : (mini    ? 0x3A4860
                                          : COLOR_TITLE_TEXT_INACT);
        XftColor icon_col;
        xft_color(wm, icon_rgb, &icon_col);
        XGlyphInfo ext;
        XftTextExtentsUtf8(wm->dpy, wm->font_title, (const FcChar8 *)letter, 1, &ext);
        int lx = icon_x + (SWL_ICON_SZ - (int)ext.width) / 2;
        int ly = icon_y + (SWL_ICON_SZ + (int)ext.height) / 2 - ext.y;
        XftDrawStringUtf8(xd, &icon_col, wm->font_title, lx, ly, (const FcChar8 *)letter, 1);
        XftColorFree(wm->dpy, wm->visual, wm->cmap, &icon_col);

        /* title below icon — prefix [..] for minimized */
        char title_buf[132];
        const char *base_title = wm->swl_titles[i];
        if (mini && !selected)
            snprintf(title_buf, sizeof(title_buf), "[%s]", base_title);
        else
            snprintf(title_buf, sizeof(title_buf), "%s", base_title);
        const char *title = title_buf;
        XftColor title_col;
        unsigned long title_rgb = selected ? COLOR_TITLE_TEXT_ACT
                                : (mini    ? 0x3A4860
                                           : COLOR_TITLE_TEXT_INACT);
        xft_color(wm, title_rgb, &title_col);
        XGlyphInfo text_ext;
        XftTextExtentsUtf8(wm->dpy, wm->font_title,
                           (const FcChar8 *)title, strlen(title), &text_ext);
        int tx = ix + (SWL_ITEM_W - (int)text_ext.width) / 2;
        if (tx < ix + 4) tx = ix + 4;
        int ty = icon_y + SWL_ICON_SZ + 4 + (int)text_ext.height - text_ext.y;
        XRectangle clip = { (short)(ix + 2), (short)(icon_y + SWL_ICON_SZ + 4),
                            (unsigned short)(SWL_ITEM_W - 4), 14 };
        XftDrawSetClipRectangles(xd, 0, 0, &clip, 1);
        XftDrawStringUtf8(xd, &title_col, wm->font_title, tx, ty,
                          (const FcChar8 *)title, strlen(title));
        XftDrawSetClip(xd, None);
        XftColorFree(wm->dpy, wm->visual, wm->cmap, &title_col);
    }

    /* scroll arrows when more windows than fit */
    if (wm->swl_count > SWL_MAX_VIS) {
        XftColor arrow;
        xft_color(wm, 0x5878A0, &arrow);
        if (vstart > 0)
            XftDrawStringUtf8(xd, &arrow, wm->font_title, 3, th / 2 + 4,
                              (const FcChar8 *)"\xe2\x97\x80", 3);
        if (vstart + SWL_MAX_VIS < wm->swl_count)
            XftDrawStringUtf8(xd, &arrow, wm->font_title, tw - 11, th / 2 + 4,
                              (const FcChar8 *)"\xe2\x96\xb6", 3);
        XftColorFree(wm->dpy, wm->visual, wm->cmap, &arrow);
    }

    XftDrawDestroy(xd);
    XFlush(wm->dpy);
}

void switcher_show(WM *wm) {
    swl_populate(wm);
    if (wm->swl_count < 2) return;

    wm->swl_idx     = 1;
    wm->swl_visible = 1;

    int vis  = swl_vis(wm);
    int tw   = vis * SWL_ITEM_W + (vis + 1) * SWL_PAD;
    int th   = SWL_ITEM_H + SWL_PAD * 2;
    int sw   = DisplayWidth(wm->dpy, wm->screen);
    int sh   = DisplayHeight(wm->dpy, wm->screen);

    XSetWindowAttributes swa;
    swa.override_redirect = True;
    swa.background_pixel  = color_alloc(wm, 0x141A28);
    swa.event_mask        = ExposureMask;
    wm->swl_win = XCreateWindow(
        wm->dpy, wm->root,
        (sw - tw) / 2, (sh - th) / 2, tw, th, 2,
        CopyFromParent, InputOutput, CopyFromParent,
        CWOverrideRedirect | CWBackPixel | CWEventMask, &swa
    );
    XSetWindowBorder(wm->dpy, wm->swl_win, color_alloc(wm, COLOR_BORDER_LIGHT));
    XMapRaised(wm->dpy, wm->swl_win);
    switcher_draw(wm);

    XGrabKeyboard(wm->dpy, wm->root, False, GrabModeAsync, GrabModeAsync, CurrentTime);
}

void switcher_next(WM *wm) {
    if (!wm->swl_visible) return;
    wm->swl_idx = (wm->swl_idx + 1) % wm->swl_count;
    switcher_draw(wm);
}

void switcher_prev(WM *wm) {
    if (!wm->swl_visible) return;
    wm->swl_idx = (wm->swl_idx - 1 + wm->swl_count) % wm->swl_count;
    switcher_draw(wm);
}

void switcher_hide(WM *wm, int commit) {
    if (!wm->swl_visible) return;
    XUngrabKeyboard(wm->dpy, CurrentTime);
    if (wm->swl_win) { XDestroyWindow(wm->dpy, wm->swl_win); wm->swl_win = 0; }
    wm->swl_visible = 0;

    if (commit && wm->swl_count > 0) {
        Client *c = client_find_by_win(wm, wm->swl_wins[wm->swl_idx]);
        if (c) {
            if (c->minimized) client_restore(wm, c);
            else              client_focus(wm, c);
        }
    }
}