/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <androidfw/ResourceTypes.h>
#include <ctype.h>

#include "AaptConfig.h"
#include "AaptAssets.h"
#include "AaptUtil.h"
#include "ResourceFilter.h"
#include "SdkConstants.h"

using android::String8;
using android::Vector;
using android::ResTable_config;

namespace AaptConfig {

static const char* kWildcardName = "any";

bool parse(const String8& str, ConfigDescription* out) {
    Vector<String8> parts = AaptUtil::splitAndLowerCase(str, '-');

    ConfigDescription config;
    AaptLocaleValue locale;
    ssize_t index = 0;
    ssize_t localeIndex = 0;
    const ssize_t N = parts.size();
    const char* part = parts[index].string();

    if (str.length() == 0) {
        goto success;
    }

    if (parseMcc(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseMnc(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    // Locale spans a few '-' separators, so we let it
    // control the index.
    localeIndex = locale.initFromDirName(parts, index);
    if (localeIndex < 0) {
        return false;
    } else if (localeIndex > index) {
        locale.writeTo(&config);
        index = localeIndex;
        if (index >= N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseLayoutDirection(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseSmallestScreenWidthDp(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseScreenWidthDp(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseScreenHeightDp(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseScreenLayoutSize(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseScreenLayoutLong(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseScreenRound(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseWideColorGamut(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseHdr(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseOrientation(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseUiModeType(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseUiModeNight(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseDensity(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseTouchscreen(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseKeysHidden(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseKeyboard(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseNavHidden(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseNavigation(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseScreenSize(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    if (parseVersion(part, &config)) {
        index++;
        if (index == N) {
            goto success;
        }
        part = parts[index].string();
    }

    // Unrecognized.
    return false;

success:
    if (out != NULL) {
        applyVersionForCompatibility(&config);
        *out = config;
    }
    return true;
}

bool parseCommaSeparatedList(const String8& str, std::set<ConfigDescription>* outSet) {
    Vector<String8> parts = AaptUtil::splitAndLowerCase(str, ',');
    const size_t N = parts.size();
    for (size_t i = 0; i < N; i++) {
        ConfigDescription config;
        if (!parse(parts[i], &config)) {
            return false;
        }
        outSet->insert(config);
    }
    return true;
}

void applyVersionForCompatibility(ConfigDescription* config) {
    if (config == NULL) {
        return;
    }

    uint16_t minSdk = 0;
    if ((config->uiMode & ResTable_config::MASK_UI_MODE_TYPE)
                == ResTable_config::UI_MODE_TYPE_VR_HEADSET
            || config->colorMode & ResTable_config::MASK_WIDE_COLOR_GAMUT
            || config->colorMode & ResTable_config::MASK_HDR) {
        minSdk = SDK_O;
    } else if (config->screenLayout2 & ResTable_config::MASK_SCREENROUND) {
        minSdk = SDK_MNC;
    } else if (config->density == ResTable_config::DENSITY_ANY) {
        minSdk = SDK_LOLLIPOP;
    } else if (config->smallestScreenWidthDp != ResTable_config::SCREENWIDTH_ANY
            || config->screenWidthDp != ResTable_config::SCREENWIDTH_ANY
            || config->screenHeightDp != ResTable_config::SCREENHEIGHT_ANY) {
        minSdk = SDK_HONEYCOMB_MR2;
    } else if ((config->uiMode & ResTable_config::MASK_UI_MODE_TYPE)
                != ResTable_config::UI_MODE_TYPE_ANY
            ||  (config->uiMode & ResTable_config::MASK_UI_MODE_NIGHT)
                != ResTable_config::UI_MODE_NIGHT_ANY) {
        minSdk = SDK_FROYO;
    } else if ((config->screenLayout & ResTable_config::MASK_SCREENSIZE)
                != ResTable_config::SCREENSIZE_ANY
            ||  (config->screenLayout & ResTable_config::MASK_SCREENLONG)
                != ResTable_config::SCREENLONG_ANY
            || config->density != ResTable_config::DENSITY_DEFAULT) {
        minSdk = SDK_DONUT;
    }

    if (minSdk > config->sdkVersion) {
        config->sdkVersion = minSdk;
    }
}

bool parseMcc(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->mcc = 0;
        return true;
    }
    const char* c = name;
    if (tolower(*c) != 'm') return false;
    c++;
    if (tolower(*c) != 'c') return false;
    c++;
    if (tolower(*c) != 'c') return false;
    c++;

    const char* val = c;

    while (*c >= '0' && *c <= '9') {
        c++;
    }
    if (*c != 0) return false;
    if (c-val != 3) return false;

    int d = atoi(val);
    if (d != 0) {
        if (out) out->mcc = d;
        return true;
    }

    return false;
}

bool parseMnc(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->mcc = 0;
        return true;
    }
    const char* c = name;
    if (tolower(*c) != 'm') return false;
    c++;
    if (tolower(*c) != 'n') return false;
    c++;
    if (tolower(*c) != 'c') return false;
    c++;

    const char* val = c;

    while (*c >= '0' && *c <= '9') {
        c++;
    }
    if (*c != 0) return false;
    if (c-val == 0 || c-val > 3) return false;

    if (out) {
        out->mnc = atoi(val);
        if (out->mnc == 0) {
            out->mnc = ACONFIGURATION_MNC_ZERO;
        }
    }

    return true;
}

bool parseLayoutDirection(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_LAYOUTDIR)
                | ResTable_config::LAYOUTDIR_ANY;
        return true;
    } else if (strcmp(name, "ldltr") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_LAYOUTDIR)
                | ResTable_config::LAYOUTDIR_LTR;
        return true;
    } else if (strcmp(name, "ldrtl") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_LAYOUTDIR)
                | ResTable_config::LAYOUTDIR_RTL;
        return true;
    }

    return false;
}

bool parseScreenLayoutSize(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENSIZE)
                | ResTable_config::SCREENSIZE_ANY;
        return true;
    } else if (strcmp(name, "small") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENSIZE)
                | ResTable_config::SCREENSIZE_SMALL;
        return true;
    } else if (strcmp(name, "normal") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENSIZE)
                | ResTable_config::SCREENSIZE_NORMAL;
        return true;
    } else if (strcmp(name, "large") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENSIZE)
                | ResTable_config::SCREENSIZE_LARGE;
        return true;
    } else if (strcmp(name, "xlarge") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENSIZE)
                | ResTable_config::SCREENSIZE_XLARGE;
        return true;
    }

    return false;
}

bool parseScreenLayoutLong(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENLONG)
                | ResTable_config::SCREENLONG_ANY;
        return true;
    } else if (strcmp(name, "long") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENLONG)
                | ResTable_config::SCREENLONG_YES;
        return true;
    } else if (strcmp(name, "notlong") == 0) {
        if (out) out->screenLayout =
                (out->screenLayout&~ResTable_config::MASK_SCREENLONG)
                | ResTable_config::SCREENLONG_NO;
        return true;
    }
    return false;
}

bool parseScreenRound(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->screenLayout2 =
                (out->screenLayout2&~ResTable_config::MASK_SCREENROUND)
                | ResTable_config::SCREENROUND_ANY;
        return true;
    } else if (strcmp(name, "round") == 0) {
        if (out) out->screenLayout2 =
                (out->screenLayout2&~ResTable_config::MASK_SCREENROUND)
                | ResTable_config::SCREENROUND_YES;
        return true;
    } else if (strcmp(name, "notround") == 0) {
        if (out) out->screenLayout2 =
                (out->screenLayout2&~ResTable_config::MASK_SCREENROUND)
                | ResTable_config::SCREENROUND_NO;
        return true;
    }
    return false;
}

bool parseWideColorGamut(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->colorMode =
                (out->colorMode&~ResTable_config::MASK_WIDE_COLOR_GAMUT)
                | ResTable_config::WIDE_COLOR_GAMUT_ANY;
        return true;
    } else if (strcmp(name, "widecg") == 0) {
        if (out) out->colorMode =
                (out->colorMode&~ResTable_config::MASK_WIDE_COLOR_GAMUT)
                | ResTable_config::WIDE_COLOR_GAMUT_YES;
        return true;
    } else if (strcmp(name, "nowidecg") == 0) {
        if (out) out->colorMode =
                (out->colorMode&~ResTable_config::MASK_WIDE_COLOR_GAMUT)
                | ResTable_config::WIDE_COLOR_GAMUT_NO;
        return true;
    }
    return false;
}

bool parseHdr(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->colorMode =
                (out->colorMode&~ResTable_config::MASK_HDR)
                | ResTable_config::HDR_ANY;
        return true;
    } else if (strcmp(name, "highdr") == 0) {
        if (out) out->colorMode =
                (out->colorMode&~ResTable_config::MASK_HDR)
                | ResTable_config::HDR_YES;
        return true;
    } else if (strcmp(name, "lowdr") == 0) {
        if (out) out->colorMode =
                (out->colorMode&~ResTable_config::MASK_HDR)
                | ResTable_config::HDR_NO;
        return true;
    }
    return false;
}

bool parseOrientation(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->orientation = out->ORIENTATION_ANY;
        return true;
    } else if (strcmp(name, "port") == 0) {
        if (out) out->orientation = out->ORIENTATION_PORT;
        return true;
    } else if (strcmp(name, "land") == 0) {
        if (out) out->orientation = out->ORIENTATION_LAND;
        return true;
    } else if (strcmp(name, "square") == 0) {
        if (out) out->orientation = out->ORIENTATION_SQUARE;
        return true;
    }

    return false;
}

bool parseUiModeType(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->uiMode =
                (out->uiMode&~ResTable_config::MASK_UI_MODE_TYPE)
                | ResTable_config::UI_MODE_TYPE_ANY;
        return true;
    } else if (strcmp(name, "desk") == 0) {
      if (out) out->uiMode =
              (out->uiMode&~ResTable_config::MASK_UI_MODE_TYPE)
              | ResTable_config::UI_MODE_TYPE_DESK;
        return true;
    } else if (strcmp(name, "car") == 0) {
      if (out) out->uiMode =
              (out->uiMode&~ResTable_config::MASK_UI_MODE_TYPE)
              | ResTable_config::UI_MODE_TYPE_CAR;
        return true;
    } else if (strcmp(name, "television") == 0) {
      if (out) out->uiMode =
              (out->uiMode&~ResTable_config::MASK_UI_MODE_TYPE)
              | ResTable_config::UI_MODE_TYPE_TELEVISION;
        return true;
    } else if (strcmp(name, "appliance") == 0) {
      if (out) out->uiMode =
              (out->uiMode&~ResTable_config::MASK_UI_MODE_TYPE)
              | ResTable_config::UI_MODE_TYPE_APPLIANCE;
        return true;
    } else if (strcmp(name, "watch") == 0) {
      if (out) out->uiMode =
              (out->uiMode&~ResTable_config::MASK_UI_MODE_TYPE)
              | ResTable_config::UI_MODE_TYPE_WATCH;
        return true;
    } else if (strcmp(name, "vrheadset") == 0) {
      if (out) out->uiMode =
              (out->uiMode&~ResTable_config::MASK_UI_MODE_TYPE)
              | ResTable_config::UI_MODE_TYPE_VR_HEADSET;
        return true;
    }

    return false;
}

bool parseUiModeNight(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->uiMode =
                (out->uiMode&~ResTable_config::MASK_UI_MODE_NIGHT)
                | ResTable_config::UI_MODE_NIGHT_ANY;
        return true;
    } else if (strcmp(name, "night") == 0) {
        if (out) out->uiMode =
                (out->uiMode&~ResTable_config::MASK_UI_MODE_NIGHT)
                | ResTable_config::UI_MODE_NIGHT_YES;
        return true;
    } else if (strcmp(name, "notnight") == 0) {
      if (out) out->uiMode =
              (out->uiMode&~ResTable_config::MASK_UI_MODE_NIGHT)
              | ResTable_config::UI_MODE_NIGHT_NO;
        return true;
    }

    return false;
}

bool parseDensity(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->density = ResTable_config::DENSITY_DEFAULT;
        return true;
    }

    if (strcmp(name, "anydpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_ANY;
        return true;
    }

    if (strcmp(name, "nodpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_NONE;
        return true;
    }

    if (strcmp(name, "ldpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_LOW;
        return true;
    }

    if (strcmp(name, "mdpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_MEDIUM;
        return true;
    }

    if (strcmp(name, "tvdpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_TV;
        return true;
    }

    if (strcmp(name, "hdpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_HIGH;
        return true;
    }

    if (strcmp(name, "xhdpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_XHIGH;
        return true;
    }

    if (strcmp(name, "xxhdpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_XXHIGH;
        return true;
    }

    if (strcmp(name, "xxxhdpi") == 0) {
        if (out) out->density = ResTable_config::DENSITY_XXXHIGH;
        return true;
    }

    char* c = (char*)name;
    while (*c >= '0' && *c <= '9') {
        c++;
    }

    // check that we have 'dpi' after the last digit.
    if (toupper(c[0]) != 'D' ||
            toupper(c[1]) != 'P' ||
            toupper(c[2]) != 'I' ||
            c[3] != 0) {
        return false;
    }

    // temporarily replace the first letter with \0 to
    // use atoi.
    char tmp = c[0];
    c[0] = '\0';

    int d = atoi(name);
    c[0] = tmp;

    if (d != 0) {
        if (out) out->density = d;
        return true;
    }

    return false;
}

bool parseTouchscreen(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->touchscreen = out->TOUCHSCREEN_ANY;
        return true;
    } else if (strcmp(name, "notouch") == 0) {
        if (out) out->touchscreen = out->TOUCHSCREEN_NOTOUCH;
        return true;
    } else if (strcmp(name, "stylus") == 0) {
        if (out) out->touchscreen = out->TOUCHSCREEN_STYLUS;
        return true;
    } else if (strcmp(name, "finger") == 0) {
        if (out) out->touchscreen = out->TOUCHSCREEN_FINGER;
        return true;
    }

    return false;
}

bool parseKeysHidden(const char* name, ResTable_config* out) {
    uint8_t mask = 0;
    uint8_t value = 0;
    if (strcmp(name, kWildcardName) == 0) {
        mask = ResTable_config::MASK_KEYSHIDDEN;
        value = ResTable_config::KEYSHIDDEN_ANY;
    } else if (strcmp(name, "keysexposed") == 0) {
        mask = ResTable_config::MASK_KEYSHIDDEN;
        value = ResTable_config::KEYSHIDDEN_NO;
    } else if (strcmp(name, "keyshidden") == 0) {
        mask = ResTable_config::MASK_KEYSHIDDEN;
        value = ResTable_config::KEYSHIDDEN_YES;
    } else if (strcmp(name, "keyssoft") == 0) {
        mask = ResTable_config::MASK_KEYSHIDDEN;
        value = ResTable_config::KEYSHIDDEN_SOFT;
    }

    if (mask != 0) {
        if (out) out->inputFlags = (out->inputFlags&~mask) | value;
        return true;
    }

    return false;
}

bool parseKeyboard(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->keyboard = out->KEYBOARD_ANY;
        return true;
    } else if (strcmp(name, "nokeys") == 0) {
        if (out) out->keyboard = out->KEYBOARD_NOKEYS;
        return true;
    } else if (strcmp(name, "qwerty") == 0) {
        if (out) out->keyboard = out->KEYBOARD_QWERTY;
        return true;
    } else if (strcmp(name, "12key") == 0) {
        if (out) out->keyboard = out->KEYBOARD_12KEY;
        return true;
    }

    return false;
}

bool parseNavHidden(const char* name, ResTable_config* out) {
    uint8_t mask = 0;
    uint8_t value = 0;
    if (strcmp(name, kWildcardName) == 0) {
        mask = ResTable_config::MASK_NAVHIDDEN;
        value = ResTable_config::NAVHIDDEN_ANY;
    } else if (strcmp(name, "navexposed") == 0) {
        mask = ResTable_config::MASK_NAVHIDDEN;
        value = ResTable_config::NAVHIDDEN_NO;
    } else if (strcmp(name, "navhidden") == 0) {
        mask = ResTable_config::MASK_NAVHIDDEN;
        value = ResTable_config::NAVHIDDEN_YES;
    }

    if (mask != 0) {
        if (out) out->inputFlags = (out->inputFlags&~mask) | value;
        return true;
    }

    return false;
}

bool parseNavigation(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) out->navigation = out->NAVIGATION_ANY;
        return true;
    } else if (strcmp(name, "nonav") == 0) {
        if (out) out->navigation = out->NAVIGATION_NONAV;
        return true;
    } else if (strcmp(name, "dpad") == 0) {
        if (out) out->navigation = out->NAVIGATION_DPAD;
        return true;
    } else if (strcmp(name, "trackball") == 0) {
        if (out) out->navigation = out->NAVIGATION_TRACKBALL;
        return true;
    } else if (strcmp(name, "wheel") == 0) {
        if (out) out->navigation = out->NAVIGATION_WHEEL;
        return true;
    }

    return false;
}

bool parseScreenSize(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) {
            out->screenWidth = out->SCREENWIDTH_ANY;
            out->screenHeight = out->SCREENHEIGHT_ANY;
        }
        return true;
    }

    const char* x = name;
    while (*x >= '0' && *x <= '9') x++;
    if (x == name || *x != 'x') return false;
    String8 xName(name, x-name);
    x++;

    const char* y = x;
    while (*y >= '0' && *y <= '9') y++;
    if (y == name || *y != 0) return false;
    String8 yName(x, y-x);

    uint16_t w = (uint16_t)atoi(xName.string());
    uint16_t h = (uint16_t)atoi(yName.string());
    if (w < h) {
        return false;
    }

    if (out) {
        out->screenWidth = w;
        out->screenHeight = h;
    }

    return true;
}

bool parseSmallestScreenWidthDp(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) {
            out->smallestScreenWidthDp = out->SCREENWIDTH_ANY;
        }
        return true;
    }

    if (*name != 's') return false;
    name++;
    if (*name != 'w') return false;
    name++;
    const char* x = name;
    while (*x >= '0' && *x <= '9') x++;
    if (x == name || x[0] != 'd' || x[1] != 'p' || x[2] != 0) return false;
    String8 xName(name, x-name);

    if (out) {
        out->smallestScreenWidthDp = (uint16_t)atoi(xName.string());
    }

    return true;
}

bool parseScreenWidthDp(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) {
            out->screenWidthDp = out->SCREENWIDTH_ANY;
        }
        return true;
    }

    if (*name != 'w') return false;
    name++;
    const char* x = name;
    while (*x >= '0' && *x <= '9') x++;
    if (x == name || x[0] != 'd' || x[1] != 'p' || x[2] != 0) return false;
    String8 xName(name, x-name);

    if (out) {
        out->screenWidthDp = (uint16_t)atoi(xName.string());
    }

    return true;
}

bool parseScreenHeightDp(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) {
            out->screenHeightDp = out->SCREENWIDTH_ANY;
        }
        return true;
    }

    if (*name != 'h') return false;
    name++;
    const char* x = name;
    while (*x >= '0' && *x <= '9') x++;
    if (x == name || x[0] != 'd' || x[1] != 'p' || x[2] != 0) return false;
    String8 xName(name, x-name);

    if (out) {
        out->screenHeightDp = (uint16_t)atoi(xName.string());
    }

    return true;
}

bool parseVersion(const char* name, ResTable_config* out) {
    if (strcmp(name, kWildcardName) == 0) {
        if (out) {
            out->sdkVersion = out->SDKVERSION_ANY;
            out->minorVersion = out->MINORVERSION_ANY;
        }
        return true;
    }

    if (*name != 'v') {
        return false;
    }

    name++;
    const char* s = name;
    while (*s >= '0' && *s <= '9') s++;
    if (s == name || *s != 0) return false;
    String8 sdkName(name, s-name);

    if (out) {
        out->sdkVersion = (uint16_t)atoi(sdkName.string());
        out->minorVersion = 0;
    }

    return true;
}

String8 getVersion(const ResTable_config& config) {
    return String8::format("v%u", config.sdkVersion);
}

bool isSameExcept(const ResTable_config& a, const ResTable_config& b, int axisMask) {
    return a.diff(b) == axisMask;
}

bool isDensityOnly(const ResTable_config& config) {
    if (config.density == ResTable_config::DENSITY_DEFAULT) {
        return false;
    }

    if (config.density == ResTable_config::DENSITY_ANY) {
        if (config.sdkVersion != SDK_LOLLIPOP) {
            // Someone modified the sdkVersion from the default, this is not safe to assume.
            return false;
        }
    } else if (config.sdkVersion != SDK_DONUT) {
        return false;
    }

    const uint32_t mask = ResTable_config::CONFIG_DENSITY | ResTable_config::CONFIG_VERSION;
    const ConfigDescription nullConfig;
    return (nullConfig.diff(config) & ~mask) == 0;
}

} // namespace AaptConfig