/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package mozilla.components.support.ktx.android.net

import android.content.ContentResolver
import android.content.Context
import android.net.Uri
import android.os.Build
import android.provider.OpenableColumns
import android.webkit.MimeTypeMap
import androidx.annotation.VisibleForTesting
import mozilla.components.support.ktx.kotlin.sanitizeFileName
import java.io.File
import java.io.IOException
import java.util.UUID

internal val commonPrefixes = listOf("www.", "mobile.", "m.")
internal val mobileSubdomains = listOf("mobile", "m")

/**
 * Returns the host without common prefixes like "www" or "m".
 */
val Uri.hostWithoutCommonPrefixes: String?
    get() {
        val host = host ?: return null
        for (prefix in commonPrefixes) {
            if (host.startsWith(prefix)) return host.substring(prefix.length)
        }
        return host
    }

/**
 * Checks that the Uri has the same host as [other], with mobile subdomains removed.
 * @param other The Uri to be compared.
 */
fun Uri.sameHostWithoutMobileSubdomainAs(other: Uri): Boolean {
    val thisHost = hostWithoutCommonPrefixes?.let {
        it.split(".")
            .filter { subdomain -> mobileSubdomains.none { mobileSubdomain -> mobileSubdomain == subdomain } }
    } ?: return false
    val otherHost = other.hostWithoutCommonPrefixes?.let {
        it.split(".")
            .filter { subdomain -> mobileSubdomains.none { mobileSubdomain -> mobileSubdomain == subdomain } }
    } ?: return false
    return thisHost == otherHost
}

/**
 * Returns true if the [Uri] uses the "http" or "https" protocol scheme.
 */
val Uri.isHttpOrHttps: Boolean
    get() = scheme == "http" || scheme == "https"

/**
 * Checks that the given URL is in one of the given URL [scopes].
 *
 * https://www.w3.org/TR/appmanifest/#dfn-within-scope
 *
 * @param scopes Uris that each represent a scope.
 * A Uri is within the scope if the origin matches and it starts with the scope's path.
 * @return True if this Uri is within any of the given scopes.
 */
fun Uri.isInScope(scopes: Iterable<Uri>): Boolean {
    val path = path.orEmpty()
    return scopes.any { scope ->
        sameOriginAs(scope) && path.startsWith(scope.path.orEmpty())
    }
}

/**
 * Checks that Uri has the same scheme and host as [other].
 */
fun Uri.sameSchemeAndHostAs(other: Uri) = scheme == other.scheme && host == other.host

/**
 * Checks that Uri has the same origin as [other].
 *
 * https://html.spec.whatwg.org/multipage/origin.html#same-origin
 */
fun Uri.sameOriginAs(other: Uri) = sameSchemeAndHostAs(other) && port == other.port

/**
 * Indicate if the [this] uri is under the application private directory.
 */
fun Uri.isUnderPrivateAppDirectory(context: Context): Boolean {
    return when (this.scheme) {
        ContentResolver.SCHEME_FILE -> {
            try {
                val uriPath = path ?: return true
                val uriCanonicalPath = File(uriPath).canonicalPath
                val dataDirCanonicalPath = File(context.applicationInfo.dataDir).canonicalPath
                if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.Q) {
                    uriCanonicalPath.startsWith(dataDirCanonicalPath)
                } else {
                    // We have to do this manual check on early builds of Android 11
                    // as symlink didn't resolve from /data/user/ to data/data
                    // we have to revise this again once Android 11 is out
                    // https://github.com/mozilla-mobile/android-components/issues/7750
                    uriCanonicalPath.startsWith("/data/data") || uriCanonicalPath.startsWith("/data/user")
                }
            } catch (e: IOException) {
                true
            }
        }
        else -> false
    }
}

/**
 * Return a file name for [this] give Uri.
 * @return A file name for the content, or generated file name if the URL is invalid or the type is unknown
 */
fun Uri.getFileName(contentResolver: ContentResolver): String {
    return when (this.scheme) {
        ContentResolver.SCHEME_FILE -> File(path ?: "").name.sanitizeFileName()
        ContentResolver.SCHEME_CONTENT -> getFileNameForContentUris(contentResolver)
        else -> {
            generateFileName(getFileExtension(contentResolver))
        }
    }
}

/**
 * Return a file extension for [this] give Uri (only supports content:// schemes).
 * @return A file extension for the content, or empty string if the URL is invalid or the type is unknown
 */
fun Uri.getFileExtension(contentResolver: ContentResolver): String {
    return MimeTypeMap.getSingleton().getExtensionFromMimeType(contentResolver.getType(this)) ?: ""
}

@VisibleForTesting
internal fun Uri.getFileNameForContentUris(contentResolver: ContentResolver): String {
    var fileName = ""
    contentResolver.query(this, null, null, null, null)?.use { cursor ->
        val nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME)
        val fileExtension = getFileExtension(contentResolver)
        fileName = if (nameIndex == -1) {
            generateFileName(fileExtension)
        } else {
            cursor.moveToFirst()
            cursor.getString(nameIndex) ?: generateFileName(fileExtension)
        }
    }
    return fileName.sanitizeFileName()
}

/**
 * Generate a file name using a randomUUID + the current timestamp.
 */
@VisibleForTesting
internal fun generateFileName(fileExtension: String = ""): String {
    val randomId = UUID.randomUUID().toString().removePrefix("-").trim()
    val timeStamp = System.currentTimeMillis()
    return if (fileExtension.isNotEmpty()) {
        "$randomId$timeStamp.$fileExtension"
    } else {
        "$randomId$timeStamp"
    }
}
