{ callPackage, stdenv, lib, fetchurl, ruby, writeText
, licenseAccepted ? false
}:

{ cmdLineToolsVersion ? "9.0"
, toolsVersion ? "26.1.1"
, platformToolsVersion ? "34.0.1"
, buildToolsVersions ? [ "33.0.2" ]
, includeEmulator ? false
, emulatorVersion ? "33.1.6"
, platformVersions ? []
, includeSources ? false
, includeSystemImages ? false
, systemImageTypes ? [ "google_apis_playstore" ]
, abiVersions ? [ "armeabi-v7a" "arm64-v8a" ]
, cmakeVersions ? [ ]
, includeNDK ? false
, ndkVersion ? "25.2.9519653"
, ndkVersions ? [ndkVersion]
, useGoogleAPIs ? false
, useGoogleTVAddOns ? false
, includeExtras ? []
, repoJson ? ./repo.json
, repoXmls ? null
, extraLicenses ? []
}:

let
  # Determine the Android os identifier from Nix's system identifier
  os = if stdenv.system == "x86_64-linux" then "linux"
    else if stdenv.system == "x86_64-darwin" then "macosx"
    else throw "No Android SDK tarballs are available for system architecture: ${stdenv.system}";

  # Uses mkrepo.rb to create a repo spec.
  mkRepoJson = { packages ? [], images ? [], addons ? [] }: let
    mkRepoRuby = (ruby.withPackages (pkgs: with pkgs; [ slop nokogiri ]));
    mkRepoRubyArguments = lib.lists.flatten [
      (builtins.map (package: ["--packages" "${package}"]) packages)
      (builtins.map (image: ["--images" "${image}"]) images)
      (builtins.map (addon: ["--addons" "${addon}"]) addons)
    ];
  in
  stdenv.mkDerivation {
    name = "androidenv-repo-json";
    buildInputs = [ mkRepoRuby ];
    preferLocalBuild = true;
    unpackPhase = "true";
    buildPhase = ''
      ruby ${./mkrepo.rb} ${lib.escapeShellArgs mkRepoRubyArguments} > repo.json
    '';
    installPhase = ''
      mv repo.json $out
    '';
  };

  # Reads the repo JSON. If repoXmls is provided, will build a repo JSON into the Nix store.
  repo = if repoXmls != null then
           let
             repoXmlSpec = {
               packages = repoXmls.packages or [];
               images = repoXmls.images or [];
               addons = repoXmls.addons or [];
             };
           in
           lib.importJSON "${mkRepoJson repoXmlSpec}"
         else
           lib.importJSON repoJson;

  # Converts all 'archives' keys in a repo spec to fetchurl calls.
  fetchArchives = attrSet:
    lib.attrsets.mapAttrsRecursive
      (path: value:
        if (builtins.elemAt path ((builtins.length path) - 1)) == "archives" then
          (builtins.listToAttrs
            (builtins.map
              (archive: lib.attrsets.nameValuePair archive.os (fetchurl { inherit (archive) url sha1; })) value))
        else value
      )
      attrSet;

  # Converts the repo attrset into fetch calls
  packages = fetchArchives repo.packages;
  system-images-packages = fetchArchives repo.images;
  addons = {
    addons = fetchArchives repo.addons;
    extras = fetchArchives repo.extras;
  };

  # Converts a license name to a list of license texts.
  mkLicenses = licenseName: repo.licenses.${licenseName};

  # Converts a list of license names to a flattened list of license texts.
  # Just used for displaying licenses.
  mkLicenseTexts = licenseNames:
    lib.lists.flatten
      (builtins.map
        (licenseName:
          builtins.map
            (licenseText: "--- ${licenseName} ---\n${licenseText}")
            (mkLicenses licenseName))
      licenseNames);

  # Converts a license name to a list of license hashes.
  mkLicenseHashes = licenseName:
    builtins.map
      (licenseText: builtins.hashString "sha1" licenseText)
      (mkLicenses licenseName);

  # The list of all license names we're accepting. Put android-sdk-license there
  # by default.
  licenseNames = lib.lists.unique ([
    "android-sdk-license"
  ] ++ extraLicenses);
in
rec {
  deployAndroidPackages = callPackage ./deploy-androidpackages.nix {
    inherit stdenv lib mkLicenses;
  };

  deployAndroidPackage = ({package, os ? null, buildInputs ? [], patchInstructions ? "", meta ? {}, ...}@args:
    let
      extraParams = removeAttrs args [ "package" "os" "buildInputs" "patchInstructions" ];
    in
    deployAndroidPackages ({
      inherit os buildInputs meta;
      packages = [ package ];
      patchesInstructions = { "${package.name}" = patchInstructions; };
    } // extraParams
  ));

  # put a much nicer error message that includes the available options.
  check-version = packages: package: version:
    if lib.hasAttrByPath [ package version ] packages then
      packages.${package}.${version}
    else
      throw ''
        The version ${version} is missing in package ${package}.
        The only available versions are ${builtins.concatStringsSep ", " (builtins.attrNames packages.${package})}.
      '';

  platform-tools = callPackage ./platform-tools.nix {
    inherit deployAndroidPackage;
    os = if stdenv.system == "aarch64-darwin" then "macosx" else os; # "macosx" is a universal binary here
    package = check-version packages "platform-tools" platformToolsVersion;
  };

  tools = callPackage ./tools.nix {
    inherit deployAndroidPackage os;
    package = check-version packages "tools" toolsVersion;

    postInstall = ''
      ${linkPlugin { name = "platform-tools"; plugin = platform-tools; }}
      ${linkPlugin { name = "patcher"; plugin = patcher; }}
      ${linkPlugin { name = "emulator"; plugin = emulator; }}
    '';
  };

  patcher = callPackage ./patcher.nix {
    inherit deployAndroidPackage os;
    package = packages.patcher."1";
  };

  build-tools = map (version:
    callPackage ./build-tools.nix {
      inherit deployAndroidPackage os;
      package = check-version packages "build-tools" version;

      postInstall = ''
        ${linkPlugin { name = "tools"; plugin = tools; check = toolsVersion != null; }}
      '';
    }
  ) buildToolsVersions;

  emulator = callPackage ./emulator.nix {
    inherit deployAndroidPackage os;
    package = check-version packages "emulator" emulatorVersion;

    postInstall = ''
      ${linkSystemImages { images = system-images; check = includeSystemImages; }}
    '';
  };

  platforms = map (version:
    deployAndroidPackage {
      inherit os;
      package = check-version packages "platforms" version;
    }
  ) platformVersions;

  sources = map (version:
    deployAndroidPackage {
      inherit os;
      package = check-version packages "sources" version;
    }
  ) platformVersions;

  system-images = lib.flatten (map (apiVersion:
    map (type:
      # Deploy all system images with the same  systemImageType in one derivation to avoid the `null` problem below
      # with avdmanager when trying to create an avd!
      #
      # ```
      # $ yes "" | avdmanager create avd --force --name testAVD --package 'system-images;android-33;google_apis;x86_64'
      # Error: Package path is not valid. Valid system image paths are:
      # null
      # ```
      let
        availablePackages = map (abiVersion:
          system-images-packages.${apiVersion}.${type}.${abiVersion}
        ) (builtins.filter (abiVersion:
          lib.hasAttrByPath [apiVersion type abiVersion] system-images-packages
        ) abiVersions);

        instructions = builtins.listToAttrs (map (package: {
            name = package.name;
            value = lib.optionalString (lib.hasPrefix "google_apis" type) ''
              # Patch 'google_apis' system images so they're recognized by the sdk.
              # Without this, `android list targets` shows 'Tag/ABIs : no ABIs' instead
              # of 'Tag/ABIs : google_apis*/*' and the emulator fails with an ABI-related error.
              sed -i '/^Addon.Vendor/d' source.properties
            '';
          }) availablePackages
        );
      in
      lib.optionals (availablePackages != [])
        (deployAndroidPackages {
          inherit os;
          packages = availablePackages;
          patchesInstructions = instructions;
        })
    ) systemImageTypes
  ) platformVersions);

  cmake = map (version:
    callPackage ./cmake.nix {
      inherit deployAndroidPackage os;
      package = check-version packages "cmake" version;
    }
  ) cmakeVersions;

  # Creates a NDK bundle.
  makeNdkBundle = ndkVersion:
    callPackage ./ndk-bundle {
      inherit deployAndroidPackage os platform-tools;
      package = packages.ndk-bundle.${ndkVersion} or packages.ndk.${ndkVersion};
    };

  # All NDK bundles.
  ndk-bundles = lib.optionals includeNDK (map makeNdkBundle ndkVersions);

  # The "default" NDK bundle.
  ndk-bundle = if includeNDK then lib.findFirst (x: x != null) null ndk-bundles else null;

  google-apis = map (version:
    deployAndroidPackage {
      inherit os;
      package = (check-version addons "addons" version).google_apis;
    }
  ) (builtins.filter (platformVersion: platformVersion < "26") platformVersions); # API level 26 and higher include Google APIs by default

  google-tv-addons = map (version:
    deployAndroidPackage {
      inherit os;
      package = (check-version addons "addons" version).google_tv_addon;
    }
  ) platformVersions;

  # Function that automatically links all plugins for which multiple versions can coexist
  linkPlugins = {name, plugins}:
    lib.optionalString (plugins != []) ''
      mkdir -p ${name}
      ${lib.concatMapStrings (plugin: ''
        ln -s ${plugin}/libexec/android-sdk/${name}/* ${name}
      '') plugins}
    '';

  # Function that automatically links all NDK plugins.
  linkNdkPlugins = {name, plugins, rootName ? name}:
    lib.optionalString (plugins != []) ''
      mkdir -p ${rootName}
      ${lib.concatMapStrings (plugin: ''
        ln -s ${plugin}/libexec/android-sdk/${name} ${rootName}/${plugin.version}
      '') plugins}
    '';

  # Function that automatically links the default NDK plugin.
  linkNdkPlugin = {name, plugin, check}:
    lib.optionalString check ''
      ln -s ${plugin}/libexec/android-sdk/${name} ${name}
    '';

  # Function that automatically links a plugin for which only one version exists
  linkPlugin = {name, plugin, check ? true}:
    lib.optionalString check ''
      ln -s ${plugin}/libexec/android-sdk/${name} ${name}
    '';

  linkSystemImages = { images, check }: lib.optionalString check ''
    mkdir -p system-images
    ${lib.concatMapStrings (system-image: ''
      apiVersion=$(basename $(echo ${system-image}/libexec/android-sdk/system-images/*))
      type=$(basename $(echo ${system-image}/libexec/android-sdk/system-images/*/*))
      mkdir -p system-images/$apiVersion
      ln -s ${system-image}/libexec/android-sdk/system-images/$apiVersion/$type system-images/$apiVersion/$type
    '') images}
  '';

  # Links all plugins related to a requested platform
  linkPlatformPlugins = {name, plugins, check}:
    lib.optionalString check ''
      mkdir -p ${name}
      ${lib.concatMapStrings (plugin: ''
        ln -s ${plugin}/libexec/android-sdk/${name}/* ${name}
      '') plugins}
    ''; # */

  # This derivation deploys the tools package and symlinks all the desired
  # plugins that we want to use. If the license isn't accepted, prints all the licenses
  # requested and throws.
  androidsdk = if !licenseAccepted then throw ''
    ${builtins.concatStringsSep "\n\n" (mkLicenseTexts licenseNames)}

    You must accept the following licenses:
    ${lib.concatMapStringsSep "\n" (str: "  - ${str}") licenseNames}

    a)
      by setting nixpkgs config option 'android_sdk.accept_license = true;'.
    b)
      by an environment variable for a single invocation of the nix tools.
        $ export NIXPKGS_ACCEPT_ANDROID_SDK_LICENSE=1
  '' else callPackage ./cmdline-tools.nix {
    inherit deployAndroidPackage os cmdLineToolsVersion;

    package = check-version packages "cmdline-tools" cmdLineToolsVersion;

    postInstall = ''
      # Symlink all requested plugins
      ${linkPlugin { name = "platform-tools"; plugin = platform-tools; }}
      ${linkPlugin { name = "tools"; plugin = tools; check = toolsVersion != null; }}
      ${linkPlugin { name = "patcher"; plugin = patcher; }}
      ${linkPlugins { name = "build-tools"; plugins = build-tools; }}
      ${linkPlugin { name = "emulator"; plugin = emulator; check = includeEmulator; }}
      ${linkPlugins { name = "platforms"; plugins = platforms; }}
      ${linkPlatformPlugins { name = "sources"; plugins = sources; check = includeSources; }}
      ${linkPlugins { name = "cmake"; plugins = cmake; }}
      ${linkNdkPlugins { name = "ndk-bundle"; rootName = "ndk"; plugins = ndk-bundles; }}
      ${linkNdkPlugin { name = "ndk-bundle"; plugin = ndk-bundle; check = includeNDK; }}
      ${linkSystemImages { images = system-images; check = includeSystemImages; }}
      ${linkPlatformPlugins { name = "add-ons"; plugins = google-apis; check = useGoogleAPIs; }}
      ${linkPlatformPlugins { name = "add-ons"; plugins = google-apis; check = useGoogleTVAddOns; }}

      # Link extras
      ${lib.concatMapStrings (identifier:
        let
          path = addons.extras.${identifier}.path;
          addon = deployAndroidPackage {
            inherit os;
            package = addons.extras.${identifier};
          };
        in
        ''
          targetDir=$(dirname ${path})
          mkdir -p $targetDir
          ln -s ${addon}/libexec/android-sdk/${path} $targetDir
        '') includeExtras}

      # Expose common executables in bin/
      mkdir -p $out/bin

      for i in ${platform-tools}/bin/*; do
          ln -s $i $out/bin
      done

      for i in ${emulator}/bin/*; do
          ln -s $i $out/bin
      done

      find $ANDROID_SDK_ROOT/cmdline-tools/${cmdLineToolsVersion}/bin -type f -executable | while read i; do
          ln -s $i $out/bin
      done

      # Write licenses
      mkdir -p licenses
      ${lib.concatMapStrings (licenseName:
        let
          licenseHashes = builtins.concatStringsSep "\n" (mkLicenseHashes licenseName);
          licenseHashFile = writeText "androidenv-${licenseName}" licenseHashes;
        in
        ''
          ln -s ${licenseHashFile} licenses/${licenseName}
        '') licenseNames}
    '';
  };
}