module Pod
  # Stores the information relative to the target used to compile a single Pod.
  # A pod can have one or more activated spec/subspecs.
  #
  class PodTarget < Target
    # @return [Array<Specification>] the spec and subspecs for the target.
    #
    attr_reader :specs

    # @return [Array<PBXNativeTarget>] the target definitions of the Podfile
    #         that generated this target.
    #
    attr_reader :target_definitions

    # @return [HeadersStore] the header directory for the target.
    #
    attr_reader :build_headers

    # @return [Bool] whether the target needs to be scoped by target definition,
    #         because the spec is used with different subspec sets across them.
    #
    # @note   For frameworks the target products of {PodTarget}s are named
    #         after their specs. The namespacing cannot directly happen in
    #         the product name itself, because this must be equal to the module
    #         name and this will be used in source code, which should stay
    #         agnostic over the dependency manager.
    #         We need namespacing because multiple targets can exist for the
    #         same podspec and their products should not collide. This
    #         duplication is needed when multiple user targets have the same
    #         dependency, but they require different sets of subspecs or they
    #         are on different platforms.
    #
    attr_reader :scoped
    alias_method :scoped?, :scoped

    # @return [Array<PodTarget>] the targets that this target has a dependency
    #         upon.
    #
    attr_accessor :dependent_targets

    # @param [Array<Specification>] @spec #see spec
    # @param [Array<TargetDefinition>] target_definitions @see target_definitions
    # @param [Sandbox] sandbox @see sandbox
    # @param [Bool] scoped @see scoped
    #
    def initialize(specs, target_definitions, sandbox, scoped = false)
      raise "Can't initialize a PodTarget without specs!" if specs.nil? || specs.empty?
      raise "Can't initialize a PodTarget without TargetDefinition!" if target_definitions.nil? || target_definitions.empty?
      super()
      @specs = specs
      @target_definitions = target_definitions
      @sandbox = sandbox
      @scoped = scoped
      @build_headers  = Sandbox::HeadersStore.new(sandbox, 'Private')
      @file_accessors = []
      @resource_bundle_targets = []
      @dependent_targets = []
    end

    # @param [Hash{Array => PodTarget}] cache
    #        the cached PodTarget for a previously scoped (specs, target_definition)
    # @return [Array<PodTarget>] a scoped copy for each target definition.
    #
    def scoped(cache = {})
      target_definitions.map do |target_definition|
        cache_key = [specs, target_definition]
        if cache[cache_key]
          cache[cache_key]
        else
          target = PodTarget.new(specs, [target_definition], sandbox, true)
          target.file_accessors = file_accessors
          target.user_build_configurations = user_build_configurations
          target.native_target = native_target
          target.archs = archs
          target.dependent_targets = dependent_targets.flat_map { |pt| pt.scoped(cache) }.select { |pt| pt.target_definitions == [target_definition] }
          cache[cache_key] = target
        end
      end
    end

    # @return [String] the label for the target.
    #
    def label
      if scoped?
        "#{target_definitions.first.label}-#{root_spec.name}"
      else
        root_spec.name
      end
    end

    # @note   The deployment target for the pod target is the maximum of all
    #         the deployment targets for the current platform of the target
    #         (or the minimum required to support the current installation
    #         strategy, if higher).
    #
    # @return [Platform] the platform for this target.
    #
    def platform
      @platform ||= begin
        platform_name = target_definitions.first.platform.name
        default = Podfile::TargetDefinition::PLATFORM_DEFAULTS[platform_name]
        deployment_target = specs.map do |spec|
          Version.new(spec.deployment_target(platform_name) || default)
        end.max
        if platform_name == :ios && requires_frameworks?
          minimum = Version.new('8.0')
          deployment_target = [deployment_target, minimum].max
        end
        Platform.new(platform_name, deployment_target)
      end
    end

    # @visibility private
    #
    attr_writer :platform

    # @return [Podfile] The podfile which declares the dependency.
    #
    def podfile
      target_definitions.first.podfile
    end

    # @return [String] The name to use for the source code module constructed
    #         for this target, and which will be used to import the module in
    #         implementation source files.
    #
    def product_module_name
      root_spec.module_name
    end

    # @return [Array<Sandbox::FileAccessor>] the file accessors for the
    #         specifications of this target.
    #
    attr_accessor :file_accessors

    # @return [Array<PBXTarget>] the resource bundle targets belonging
    #         to this target.
    attr_reader :resource_bundle_targets

    # @return [Bool] Whether or not this target should be build.
    #
    # A target should not be build if it has no source files.
    #
    def should_build?
      source_files = file_accessors.flat_map(&:source_files)
      source_files -= file_accessors.flat_map(&:headers)
      !source_files.empty?
    end

    # @return [Array<Specification::Consumer>] the specification consumers for
    #         the target.
    #
    def spec_consumers
      specs.map { |spec| spec.consumer(platform) }
    end

    # @return [Boolean] Whether the target uses Swift code
    #
    def uses_swift?
      file_accessors.any? do |file_accessor|
        file_accessor.source_files.any? { |sf| sf.extname == '.swift' }
      end
    end

    # @return [Specification] The root specification for the target.
    #
    def root_spec
      specs.first.root
    end

    # @return [String] The name of the Pod that this target refers to.
    #
    def pod_name
      root_spec.name
    end

    # @param  [String] bundle_name
    #         The name of the bundle product, which is given by the +spec+.
    #
    # @return [String] The derived name of the resource bundle target.
    #
    def resources_bundle_target_label(bundle_name)
      "#{label}-#{bundle_name}"
    end

    # @return [Array<String>] The names of the Pods on which this target
    #         depends.
    #
    def dependencies
      spec_consumers.flat_map do |consumer|
        consumer.dependencies.map { |dep| Specification.root_name(dep.name) }
      end.uniq
    end

    # Checks if the target should be included in the build configuration with
    # the given name of a given target definition.
    #
    # @param  [TargetDefinition] target_definition
    #         The target definition to check.
    #
    # @param  [String] configuration_name
    #         The name of the build configuration.
    #
    def include_in_build_config?(target_definition, configuration_name)
      whitelists = target_definition_dependencies(target_definition).map do |dependency|
        target_definition.pod_whitelisted_for_configuration?(dependency.name, configuration_name)
      end.uniq

      if whitelists.empty?
        return true
      elsif whitelists.count == 1
        whitelists.first
      else
        raise Informative, "The subspecs of `#{pod_name}` are linked to " \
          "different build configurations for the `#{target_definition}` " \
          'target. CocoaPods does not currently support subspecs across ' \
          'different build configurations.'
      end
    end

    # Checks if warnings should be inhibited for this pod.
    #
    # @return [Bool]
    #
    def inhibit_warnings?
      whitelists = target_definitions.map do |target_definition|
        target_definition.inhibits_warnings_for_pod?(root_spec.name)
      end.uniq

      if whitelists.empty?
        return false
      elsif whitelists.count == 1
        whitelists.first
      else
        UI.warn "The pod `#{pod_name}` is linked to different targets " \
          "(#{target_definitions.map(&:label)}), which contain different " \
          'settings to inhibit warnings. CocoaPods does not currently ' \
          'support different settings and will fall back to your preference ' \
          'set in the root target definition.'
        return podfile.root_target_definitions.first.inhibits_warnings_for_pod?(root_spec.name)
      end
    end

    # @return [String] The configuration build dir, relevant if the target is
    #         integrated as framework.
    #
    def configuration_build_dir
      if scoped?
        "$(BUILD_DIR)/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/#{target_definitions.first.label}"
      else
        '$(BUILD_DIR)/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)'
      end
    end

    private

    # @param  [TargetDefinition] target_definition
    #         The target definition to check.
    #
    # @return [Array<Dependency>] The dependency of the target definition for
    #         this Pod. Return an empty array if the Pod is not a direct
    #         dependency of the target definition but the dependency of one or
    #         more Pods.
    #
    def target_definition_dependencies(target_definition)
      target_definition.dependencies.select do |dependency|
        Specification.root_name(dependency.name) == pod_name
      end
    end
  end
end
