/*
 * Copyright (C) 2017 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 "configuration/ConfigurationParser.h"

#include <algorithm>
#include <functional>
#include <memory>
#include <utility>

#include <android-base/logging.h>

#include "ConfigDescription.h"
#include "Diagnostics.h"
#include "util/Util.h"
#include "xml/XmlActionExecutor.h"
#include "xml/XmlDom.h"
#include "xml/XmlUtil.h"

namespace aapt {

namespace {

using ::aapt::configuration::Abi;
using ::aapt::configuration::AndroidManifest;
using ::aapt::configuration::AndroidSdk;
using ::aapt::configuration::Artifact;
using ::aapt::configuration::Configuration;
using ::aapt::configuration::GlTexture;
using ::aapt::configuration::Group;
using ::aapt::configuration::Locale;
using ::aapt::util::TrimWhitespace;
using ::aapt::xml::Element;
using ::aapt::xml::FindRootElement;
using ::aapt::xml::NodeCast;
using ::aapt::xml::XmlActionExecutor;
using ::aapt::xml::XmlActionExecutorPolicy;
using ::aapt::xml::XmlNodeAction;

const std::unordered_map<std::string, Abi> kAbiMap = {
    {"armeabi", Abi::kArmeV6},
    {"armeabi-v7a", Abi::kArmV7a},
    {"arm64-v8a", Abi::kArm64V8a},
    {"x86", Abi::kX86},
    {"x86_64", Abi::kX86_64},
    {"mips", Abi::kMips},
    {"mips64", Abi::kMips64},
    {"universal", Abi::kUniversal},
};

constexpr const char* kAaptXmlNs = "http://schemas.android.com/tools/aapt";

/** A default noop diagnostics context. */
class NoopDiagnostics : public IDiagnostics {
 public:
  void Log(Level level, DiagMessageActual& actualMsg) override {}
};
NoopDiagnostics noop_;

std::string GetLabel(const Element* element, IDiagnostics* diag) {
  std::string label;
  for (const auto& attr : element->attributes) {
    if (attr.name == "label") {
      label = attr.value;
      break;
    }
  }

  if (label.empty()) {
    diag->Error(DiagMessage() << "No label found for element " << element->name);
  }
  return label;
}

/** XML node visitor that removes all of the namespace URIs from the node and all children. */
class NamespaceVisitor : public xml::Visitor {
 public:
  void Visit(xml::Element* node) override {
    node->namespace_uri.clear();
    VisitChildren(node);
  }
};

}  // namespace

ConfigurationParser::ConfigurationParser(std::string contents)
    : contents_(std::move(contents)),
      diag_(&noop_) {
}

Maybe<Configuration> ConfigurationParser::Parse() {
  std::istringstream in(contents_);

  auto doc = xml::Inflate(&in, diag_, Source("config.xml"));
  if (!doc) {
    return {};
  }

  // Strip any namespaces from the XML as the XmlActionExecutor ignores anything with a namespace.
  auto* root = FindRootElement(doc.get());
  if (root == nullptr) {
    diag_->Error(DiagMessage() << "Could not find the root element in the XML document");
    return {};
  }

  std::string& xml_ns = root->namespace_uri;
  if (!xml_ns.empty()) {
    if (xml_ns != kAaptXmlNs) {
      diag_->Error(DiagMessage() << "Unknown namespace found on root element: " << xml_ns);
      return {};
    }

    xml_ns.clear();
    NamespaceVisitor visitor;
    root->Accept(&visitor);
  }

  XmlActionExecutor executor;
  XmlNodeAction& root_action = executor["post-process"];
  XmlNodeAction& artifacts_action = root_action["artifacts"];
  XmlNodeAction& groups_action = root_action["groups"];

  Configuration config;

  // Helper to bind a static method to an action handler in the DOM executor.
  auto bind_handler = [&config](std::function<bool(Configuration*, Element*, IDiagnostics*)> h)
      -> XmlNodeAction::ActionFuncWithDiag {
    return std::bind(h, &config, std::placeholders::_1, std::placeholders::_2);
  };

  // Parse the artifact elements.
  artifacts_action["artifact"].Action(bind_handler(artifact_handler_));
  artifacts_action["artifact-format"].Action(bind_handler(artifact_format_handler_));

  // Parse the different configuration groups.
  groups_action["abi-group"].Action(bind_handler(abi_group_handler_));
  groups_action["screen-density-group"].Action(bind_handler(screen_density_group_handler_));
  groups_action["locale-group"].Action(bind_handler(locale_group_handler_));
  groups_action["android-sdk-group"].Action(bind_handler(android_sdk_group_handler_));
  groups_action["gl-texture-group"].Action(bind_handler(gl_texture_group_handler_));
  groups_action["device-feature-group"].Action(bind_handler(device_feature_group_handler_));

  if (!executor.Execute(XmlActionExecutorPolicy::kNone, diag_, doc.get())) {
    diag_->Error(DiagMessage() << "Could not process XML document");
    return {};
  }

  return {config};
}

ConfigurationParser::ActionHandler ConfigurationParser::artifact_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      Artifact artifact{};
      for (const auto& attr : root_element->attributes) {
        if (attr.name == "name") {
          artifact.name = attr.value;
        } else if (attr.name == "abi-group") {
          artifact.abi_group = {attr.value};
        } else if (attr.name == "screen-density-group") {
          artifact.screen_density_group = {attr.value};
        } else if (attr.name == "locale-group") {
          artifact.locale_group = {attr.value};
        } else if (attr.name == "android-sdk-group") {
          artifact.android_sdk_group = {attr.value};
        } else if (attr.name == "gl-texture-group") {
          artifact.gl_texture_group = {attr.value};
        } else if (attr.name == "device-feature-group") {
          artifact.device_feature_group = {attr.value};
        } else {
          diag->Note(
              DiagMessage() << "Unknown artifact attribute: " << attr.name << " = " << attr.value);
        }
      }
      config->artifacts[artifact.name] = artifact;
      return true;
    };

ConfigurationParser::ActionHandler ConfigurationParser::artifact_format_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      for (auto& node : root_element->children) {
        xml::Text* t;
        if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
          config->artifact_format = TrimWhitespace(t->text).to_string();
          break;
        }
      }
      return true;
    };

ConfigurationParser::ActionHandler ConfigurationParser::abi_group_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      std::string label = GetLabel(root_element, diag);
      if (label.empty()) {
        return false;
      }

      auto& group = config->abi_groups[label];
      bool valid = true;

      for (auto* child : root_element->GetChildElements()) {
        if (child->name != "abi") {
          diag->Error(
              DiagMessage() << "Unexpected element in ABI group: " << child->name);
          valid = false;
        } else {
          for (auto& node : child->children) {
            xml::Text* t;
            if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
              group.push_back(kAbiMap.at(TrimWhitespace(t->text).to_string()));
              break;
            }
          }
        }
      }

      return valid;
    };

ConfigurationParser::ActionHandler ConfigurationParser::screen_density_group_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      std::string label = GetLabel(root_element, diag);
      if (label.empty()) {
        return false;
      }

      auto& group = config->screen_density_groups[label];
      bool valid = true;

      for (auto* child : root_element->GetChildElements()) {
        if (child->name != "screen-density") {
          diag->Error(
              DiagMessage() << "Unexpected root_element in screen density group: "
                            << child->name);
          valid = false;
        } else {
          for (auto& node : child->children) {
            xml::Text* t;
            if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
              ConfigDescription config_descriptor;
              const android::StringPiece& text = TrimWhitespace(t->text);
              if (ConfigDescription::Parse(text, &config_descriptor)) {
                // Copy the density with the minimum SDK version stripped out.
                group.push_back(config_descriptor.CopyWithoutSdkVersion());
              } else {
                diag->Error(
                    DiagMessage() << "Could not parse config descriptor for screen-density: "
                                  << text);
                valid = false;
              }
              break;
            }
          }
        }
      }

      return valid;
    };

ConfigurationParser::ActionHandler ConfigurationParser::locale_group_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      std::string label = GetLabel(root_element, diag);
      if (label.empty()) {
        return false;
      }

      auto& group = config->locale_groups[label];
      bool valid = true;

      for (auto* child : root_element->GetChildElements()) {
        if (child->name != "locale") {
          diag->Error(
              DiagMessage() << "Unexpected root_element in screen density group: "
                            << child->name);
          valid = false;
        } else {
          Locale entry;
          for (const auto& attr : child->attributes) {
            if (attr.name == "lang") {
              entry.lang = {attr.value};
            } else if (attr.name == "region") {
              entry.region = {attr.value};
            } else {
              diag->Warn(DiagMessage() << "Unknown attribute: " << attr.name
                                       << " = " << attr.value);
            }
          }
          group.push_back(entry);
        }
      }

      return valid;
    };

ConfigurationParser::ActionHandler ConfigurationParser::android_sdk_group_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      std::string label = GetLabel(root_element, diag);
      if (label.empty()) {
        return false;
      }

      auto& group = config->android_sdk_groups[label];
      bool valid = true;

      for (auto* child : root_element->GetChildElements()) {
        if (child->name != "android-sdk") {
          diag->Error(
              DiagMessage() << "Unexpected root_element in ABI group: " << child->name);
          valid = false;
        } else {
          AndroidSdk entry;
          for (const auto& attr : child->attributes) {
            if (attr.name == "minSdkVersion") {
              entry.min_sdk_version = {attr.value};
            } else if (attr.name == "targetSdkVersion") {
              entry.target_sdk_version = {attr.value};
            } else if (attr.name == "maxSdkVersion") {
              entry.max_sdk_version = {attr.value};
            } else {
              diag->Warn(DiagMessage() << "Unknown attribute: " << attr.name
                                       << " = " << attr.value);
            }
          }

          // TODO: Fill in the manifest details when they are finalised.
          for (auto node : child->GetChildElements()) {
            if (node->name == "manifest") {
              if (entry.manifest) {
                diag->Warn(DiagMessage() << "Found multiple manifest tags. Ignoring duplicates.");
                continue;
              }
              entry.manifest = {AndroidManifest()};
            }
          }

          group.push_back(entry);
        }
      }

      return valid;
    };

ConfigurationParser::ActionHandler ConfigurationParser::gl_texture_group_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      std::string label = GetLabel(root_element, diag);
      if (label.empty()) {
        return false;
      }

      auto& group = config->gl_texture_groups[label];
      bool valid = true;

      GlTexture result;
      for (auto* child : root_element->GetChildElements()) {
        if (child->name != "gl-texture") {
          diag->Error(
              DiagMessage() << "Unexpected element in GL texture group: "
                            << child->name);
          valid = false;
        } else {
          for (const auto& attr : child->attributes) {
            if (attr.name == "name") {
              result.name = attr.value;
              break;
            }
          }

          for (auto* element : child->GetChildElements()) {
            if (element->name != "texture-path") {
              diag->Error(
                  DiagMessage() << "Unexpected element in gl-texture element: "
                                << child->name);
              valid = false;
              continue;
            }
            for (auto& node : element->children) {
              xml::Text* t;
              if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
                result.texture_paths.push_back(TrimWhitespace(t->text).to_string());
              }
            }
          }
        }
        group.push_back(result);
      }

      return valid;
    };

ConfigurationParser::ActionHandler ConfigurationParser::device_feature_group_handler_ =
    [](Configuration* config, Element* root_element, IDiagnostics* diag) -> bool {
      std::string label = GetLabel(root_element, diag);
      if (label.empty()) {
        return false;
      }

      auto& group = config->device_feature_groups[label];
      bool valid = true;

      for (auto* child : root_element->GetChildElements()) {
        if (child->name != "supports-feature") {
          diag->Error(
              DiagMessage() << "Unexpected root_element in device feature group: "
                            << child->name);
          valid = false;
        } else {
          for (auto& node : child->children) {
            xml::Text* t;
            if ((t = NodeCast<xml::Text>(node.get())) != nullptr) {
              group.push_back(TrimWhitespace(t->text).to_string());
              break;
            }
          }
        }
      }

      return valid;
    };

}  // namespace aapt