/*
 * Copyright (C) 2015 Square, Inc.
 *
 * 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.
 */
package com.squareup.leakcanary.deobfuscation

import java.io.File
import org.gradle.api.DefaultTask
import org.gradle.api.GradleException
import org.gradle.api.provider.Property
import org.gradle.api.tasks.CacheableTask
import org.gradle.api.tasks.Input
import org.gradle.api.tasks.InputDirectory
import org.gradle.api.tasks.InputFile
import org.gradle.api.tasks.OutputFile
import org.gradle.api.tasks.PathSensitive
import org.gradle.api.tasks.PathSensitivity
import org.gradle.api.tasks.TaskAction

@CacheableTask
abstract class CopyObfuscationMappingFileTask : DefaultTask() {

  @Input
  var variantName: String = ""

  @get:InputFile
  @get:PathSensitive(PathSensitivity.RELATIVE)
  abstract val mappingFile: Property<File?>

  @get:InputDirectory
  @get:PathSensitive(PathSensitivity.RELATIVE)
  abstract val mergeAssetsDirectory: Property<File>

  @get:OutputFile
  val leakCanaryAssetsOutputFile: File
    get() = File(mergeAssetsDirectory.orNull, "leakCanaryObfuscationMapping.txt")

  init {
    description = "Puts obfuscation mapping file in assets directory."
  }

  @TaskAction
  fun copyObfuscationMappingFile() {
    val mapping = validateMappingFile()
    validateMergeAssetsDir()
    mapping.copyTo(leakCanaryAssetsOutputFile, overwrite = true)
  }

  private fun validateMappingFile(): File {
    val mapping = mappingFile.orNull
    if (mapping == null || !mapping.exists()) {
      throw GradleException(
        """
        The plugin was configured to be applied to a variant which doesn't define
        an obfuscation mapping file: make sure that isMinified is true for variant: $variantName.
        """
      )
    }
    return mapping
  }

  private fun validateMergeAssetsDir() {
    mergeAssetsDirectory.orNull?.let { mergeAssetsDir ->
      if (!mergeAssetsDir.exists()) {
        val mergeAssetsDirCreated = mergeAssetsDir.mkdirs()
        if (!mergeAssetsDirCreated) {
          throw GradleException(
            "Obfuscation mapping destination dir doesn't exist and it's impossible to create it."
          )
        }
      }
    } ?: throw GradleException("Obfuscation mapping is null.")
  }
}