Add tests for `ViewIntentFinder`

package com.fsck.k9.ui.messageview

import android.content.ComponentName

import android.content.Context

import android.content.Intent

import android.content.IntentFilter

import android.content.pm.PackageInfo

import android.content.pm.ProviderInfo

import androidx.core.net.toUri

import androidx.test.core.app.ApplicationProvider

import app.k9mail.core.android.testing.RobolectricTest

import assertk.all

import assertk.assertThat

import assertk.assertions.isEqualTo

import assertk.assertions.prop

import com.fsck.k9.provider.AttachmentTempFileProvider

import kotlin.test.Test

import org.junit.Before

import org.robolectric.Robolectric

import org.robolectric.Shadows.shadowOf

class ViewIntentFinderTest : RobolectricTest() {

    private val context = ApplicationProvider.getApplicationContext<Context>()

    private val attachmentTempFileProviderAuthority = "${context.packageName}.tempfileprovider"

    private val viewIntentFinder = ViewIntentFinder(context)

    @Before

    fun setUp() {

        // The AttachmentTempFileProvider methods called by ViewIntentFinder require the AUTHORITY property to be

        // set. The most robust way to accomplish this is to properly initialize the content provider.

        initializeAttachmentTempFileProvider()

    }

    @Test

    fun `provided non-default content type should be preferred`() {

        addViewerAppFor(mimeType = "application/pdf")

        addViewerAppFor(mimeType = "application/octet-stream")

        val contentUri = "content://$attachmentTempFileProviderAuthority/id".toUri()

        val displayName = "document.pdf"

        val mimeType = "application/pdf"

        val result = viewIntentFinder.getBestViewIntent(contentUri, displayName, mimeType)

        assertThat(result).all {

            prop(Intent::getAction).isEqualTo(Intent.ACTION_VIEW)

            prop(Intent::getData).isEqualTo(

                "content://$attachmentTempFileProviderAuthority/id?mime_type=application%2Fpdf".toUri(),

            )

            prop(Intent::getType).isEqualTo("application/pdf")

        }

    }

    @Test

    fun `inferred content type should be preferred over provided default content type`() {

        addViewerAppFor(mimeType = "application/pdf")

        addViewerAppFor(mimeType = "application/octet-stream")

        val contentUri = "content://$attachmentTempFileProviderAuthority/id".toUri()

        val displayName = "document.pdf"

        val mimeType = "application/octet-stream"

        val result = viewIntentFinder.getBestViewIntent(contentUri, displayName, mimeType)

        assertThat(result).all {

            prop(Intent::getAction).isEqualTo(Intent.ACTION_VIEW)

            prop(Intent::getData).isEqualTo(

                "content://$attachmentTempFileProviderAuthority/id?mime_type=application%2Fpdf".toUri(),

            )

            prop(Intent::getType).isEqualTo("application/pdf")

        }

    }

    @Test

    fun `inferred content type should be used when no app is installed for provided content type`() {

        addViewerAppFor(mimeType = "text/plain")

        addViewerAppFor(mimeType = "application/octet-stream")

        val contentUri = "content://$attachmentTempFileProviderAuthority/id".toUri()

        val displayName = "document.txt"

        val mimeType = "text/fancy-format"

        val result = viewIntentFinder.getBestViewIntent(contentUri, displayName, mimeType)

        assertThat(result).all {

            prop(Intent::getAction).isEqualTo(Intent.ACTION_VIEW)

            prop(Intent::getData).isEqualTo(

                "content://$attachmentTempFileProviderAuthority/id?mime_type=text%2Fplain".toUri(),

            )

            prop(Intent::getType).isEqualTo("text/plain")

        }

    }

    @Test

    fun `fall back to default content type when no app is installed for provided content type`() {

        addViewerAppFor(mimeType = "application/octet-stream")

        val contentUri = "content://$attachmentTempFileProviderAuthority/id".toUri()

        val displayName = "document.pdf"

        val mimeType = "application/pdf"

        val result = viewIntentFinder.getBestViewIntent(contentUri, displayName, mimeType)

        assertThat(result).all {

            prop(Intent::getAction).isEqualTo(Intent.ACTION_VIEW)

            prop(Intent::getData).isEqualTo(

                "content://$attachmentTempFileProviderAuthority/id?mime_type=application%2Foctet-stream".toUri(),

            )

            prop(Intent::getType).isEqualTo("application/octet-stream")

        }

    }

    private fun initializeAttachmentTempFileProvider() {

        val info = ProviderInfo().apply {

            authority = attachmentTempFileProviderAuthority

            grantUriPermissions = true

        }

        Robolectric.buildContentProvider(AttachmentTempFileProvider::class.java).create(info)

    }

    private var packageCounter = 1

    private fun addViewerAppFor(mimeType: String) {

        val viewerPackageName = "test.viewerapp.$packageCounter"

        val viewerActivityName = "$viewerPackageName.activity"

        packageCounter++

        val packageManager = shadowOf(context.packageManager)

        packageManager.installPackage(

            PackageInfo().apply {

                packageName = viewerPackageName

            },

        )

        val viewerActivityComponentName = ComponentName(viewerPackageName, viewerActivityName)

        packageManager.addActivityIfNotPresent(viewerActivityComponentName)

        val intentFilter = IntentFilter(Intent.ACTION_VIEW).apply {

            addDataType(mimeType)

            addDataScheme("content")

            addCategory(Intent.CATEGORY_DEFAULT)

        }

        packageManager.addIntentFilterForActivity(viewerActivityComponentName, intentFilter)

    }

}