// file      : bpkg/manifest -*- C++ -*-
// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#ifndef BPKG_MANIFEST
#define BPKG_MANIFEST

#include <string>
#include <vector>
#include <cassert>
#include <cstdint>   // uint16_t
#include <ostream>
#include <utility>   // move()
#include <stdexcept> // logic_error

#include <butl/path>
#include <butl/optional>
#include <butl/manifest-forward>

#include <bpkg/export>
#include <bpkg/version>

namespace bpkg
{
  using strings = std::vector<std::string>;

  // @@ Let's create <bpkg/types> with "basic" package types.
  //
  class LIBBPKG_EXPORT version
  {
  public:
    // Let's keep the members in the order they appear in the string
    // representation.
    //
    const std::uint16_t epoch;
    const std::string upstream;
    const butl::optional<std::string> release;
    const std::uint16_t revision;

    // Upstream part canonical representation.
    //
    const std::string canonical_upstream;

    // Release part canonical representation.
    //
    const std::string canonical_release;

    // Create a special empty version. It is less than any other valid
    // version (and is conceptually equivalent to 0-).
    //
    version (): epoch (0), release (""), revision (0) {}

    // Throw std::invalid_argument if the passed string is not a valid
    // version representation.
    //
    explicit
    version (const std::string& v): version (v.c_str ()) {}

    explicit
    version (const char* v): version (data_type (v, data_type::parse::full)) {}

    // Create the version object from separate epoch, upstream, release, and
    // revision parts.
    //
    // Note that it is possible (and legal) to create the special empty
    // version via this interface as version(0, string(), string(), 0).
    //
    version (std::uint16_t epoch,
             std::string upstream,
             butl::optional<std::string> release,
             std::uint16_t revision);

    version (version&&) = default;
    version (const version&) = default;
    version& operator= (version&&);
    version& operator= (const version&);

    std::string
    string (bool ignore_revision = false) const;

    bool
    operator< (const version& v) const noexcept {return compare (v) < 0;}

    bool
    operator> (const version& v) const noexcept {return compare (v) > 0;}

    bool
    operator== (const version& v) const noexcept {return compare (v) == 0;}

    bool
    operator<= (const version& v) const noexcept {return compare (v) <= 0;}

    bool
    operator>= (const version& v) const noexcept {return compare (v) >= 0;}

    bool
    operator!= (const version& v) const noexcept {return compare (v) != 0;}

    int
    compare (const version& v, bool ignore_revision = false) const noexcept
    {
      if (epoch != v.epoch)
        return epoch < v.epoch ? -1 : 1;

      if (int c = canonical_upstream.compare (v.canonical_upstream))
        return c;

      if (int c = canonical_release.compare (v.canonical_release))
        return c;

      if (!ignore_revision && revision != v.revision)
        return revision < v.revision ? -1 : 1;

      return 0;
    }

    bool
    empty () const noexcept
    {
      bool e (upstream.empty ());
      assert (!e ||
              (epoch == 0 && release && release->empty () && revision == 0));
      return e;
    }

  private:
    struct LIBBPKG_EXPORT data_type
    {
      enum class parse {full, upstream, release};

      data_type (const char*, parse);

      std::uint16_t epoch;
      std::string upstream;
      butl::optional<std::string> release;
      std::uint16_t revision;
      std::string canonical_upstream;
      std::string canonical_release;
    };

    explicit
    version (data_type&& d)
        : epoch (d.epoch),
          upstream (std::move (d.upstream)),
          release (std::move (d.release)),
          revision (d.revision),
          canonical_upstream (std::move (d.canonical_upstream)),
          canonical_release (std::move (d.canonical_release)) {}
  };

  inline std::ostream&
  operator<< (std::ostream& os, const version& v)
  {
    return os << (v.empty () ? "<empty-version>" : v.string ());
  }

  // priority
  //
  class priority
  {
  public:
    enum value_type {low, medium, high, security};

    value_type value; // Shouldn't be necessary to access directly.
    std::string comment;

    priority (value_type v = low, std::string c = "")
        : value (v), comment (std::move (c)) {}

    operator value_type () const {return value;}
  };

  // description
  // description-file
  // change
  // change-file
  //
  class LIBBPKG_EXPORT text_file
  {
  public:
    using path_type = butl::path;

    bool file;

    union
    {
      std::string text;
      path_type path;
    };

    std::string comment;

    // File text constructor.
    //
    explicit
    text_file (std::string t = ""): file (false), text (std::move (t)) {}

    // File reference constructor.
    //
    text_file (path_type p, std::string c)
        : file (true), path (std::move (p)), comment (std::move (c)) {}

    text_file (text_file&&);
    text_file (const text_file&);
    text_file& operator= (text_file&&);
    text_file& operator= (const text_file&);

    ~text_file ();
  };

  // license
  //
  class licenses: public strings
  {
  public:
    std::string comment;

    explicit
    licenses (std::string c = ""): comment (std::move (c)) {}
  };

  // url
  // package-url
  //
  class url: public std::string
  {
  public:
    std::string comment;

    explicit
    url (std::string u = "", std::string c = "")
        : std::string (std::move (u)), comment (std::move (c)) {}
  };

  // email
  // package-email
  // build-email
  //
  class email: public std::string
  {
  public:
    std::string comment;

    explicit
    email (std::string e = "", std::string c = "")
        : std::string (std::move (e)), comment (std::move (c)) {}
  };

  // depends
  //
  struct LIBBPKG_EXPORT dependency_constraint
  {
    butl::optional<version> min_version;
    butl::optional<version> max_version;
    bool min_open;
    bool max_open;

    dependency_constraint (butl::optional<version> min_version, bool min_open,
                           butl::optional<version> max_version, bool max_open);

    dependency_constraint (const version& v)
        : dependency_constraint (v, false, v, false) {}

    dependency_constraint () = default;

    bool
    empty () const noexcept {return !min_version && !max_version;}
  };

  LIBBPKG_EXPORT std::ostream&
  operator<< (std::ostream&, const dependency_constraint&);

  inline bool
  operator== (const dependency_constraint& x, const dependency_constraint& y)
  {
    return x.min_version == y.min_version && x.max_version == y.max_version &&
      x.min_open == y.min_open && x.max_open == y.max_open;
  }

  inline bool
  operator!= (const dependency_constraint& x, const dependency_constraint& y)
  {
    return !(x == y);
  }

  struct dependency
  {
    std::string name;
    butl::optional<dependency_constraint> constraint;
  };

  LIBBPKG_EXPORT std::ostream&
  operator<< (std::ostream&, const dependency&);

  class dependency_alternatives: public std::vector<dependency>
  {
  public:
    bool conditional;
    bool buildtime;
    std::string comment;

    dependency_alternatives () = default;
    dependency_alternatives (bool d, bool b, std::string c)
        : conditional (d), buildtime (b), comment (std::move (c)) {}
  };

  LIBBPKG_EXPORT std::ostream&
  operator<< (std::ostream&, const dependency_alternatives&);

  // requires
  //
  class requirement_alternatives: public strings
  {
  public:
    bool conditional;
    bool buildtime;
    std::string comment;

    requirement_alternatives () = default;
    requirement_alternatives (bool d, bool b, std::string c)
        : conditional (d), buildtime (b), comment (std::move (c)) {}
  };

  class LIBBPKG_EXPORT package_manifest
  {
  public:
    using version_type = bpkg::version;
    using priority_type = bpkg::priority;
    using url_type = bpkg::url;
    using email_type = bpkg::email;

    std::string name;
    version_type version;
    butl::optional<priority_type> priority;
    std::string summary;
    std::vector<licenses> license_alternatives;
    strings tags;
    butl::optional<text_file> description;
    std::vector<text_file> changes;
    url_type url;
    butl::optional<url_type> package_url;
    email_type email;
    butl::optional<email_type> package_email;
    butl::optional<email_type> build_email;
    std::vector<dependency_alternatives> dependencies;
    std::vector<requirement_alternatives> requirements;

    // The following values are only valid in the manifest list.
    //
    butl::optional<butl::path> location;
    butl::optional<std::string> sha256sum;

  public:
    package_manifest () = default; // VC export.

    // Create individual package manifest.
    //
    package_manifest (butl::manifest_parser&, bool ignore_unknown = false);

    // Create an element of the package list manifest.
    //
    package_manifest (butl::manifest_parser&,
                      butl::manifest_name_value start,
                      bool ignore_unknown = false);

    void
    serialize (butl::manifest_serializer&) const;

  private:
    package_manifest (butl::manifest_parser&,
                      butl::manifest_name_value start,
                      bool in_list,
                      bool ignore_unknown);
  };

  class LIBBPKG_EXPORT package_manifests: public std::vector<package_manifest>
  {
  public:
    using base_type = std::vector<package_manifest>;

    using base_type::base_type;

    // Checksum of the corresponding repository_manifests.
    //
    std::string sha256sum;

  public:
    package_manifests () = default;
    package_manifests (butl::manifest_parser&, bool ignore_unknown = false);

    void
    serialize (butl::manifest_serializer&) const;
  };

  class LIBBPKG_EXPORT repository_location
  {
  public:
    // Create a special empty repository_location.
    //
    repository_location () = default;

    // If the argument is not empty, create remote/absolute repository
    // location. Throw std::invalid_argument if the location is a relative
    // path. If the argument is empty, then create the special empty
    // location.
    //
    explicit
    repository_location (const std::string&);

    // Create a potentially relative repository location. If base is not
    // empty, use it to complete the relative location to remote/absolute.
    // Throw std::invalid_argument if base is not empty but the location is
    // empty, base itself is relative, or the resulting completed location
    // is invalid.
    //
    repository_location (const std::string&, const repository_location& base);

    repository_location (const repository_location& l,
                         const repository_location& base)
        : repository_location (l.string (), base) {}

    // Note that relative locations have no canonical name. Canonical
    // name of an empty location is the empty name.
    //
    const std::string&
    canonical_name () const noexcept {return canonical_name_;}

    // There are 3 types of locations: remote, local absolute filesystem
    // path and local relative filesystem path. Plus there is the special
    // empty location. The following predicates can be used to determine
    // what kind of location it is. Note that except for empty(), all the
    // other predicates throw std::logic_error for an empty location.
    //
    bool
    empty () const noexcept {return path_.empty ();}

    bool
    local () const
    {
      if (empty ())
        throw std::logic_error ("empty location");

      return host_.empty ();
    }

    bool
    remote () const
    {
      return !local ();
    }

    bool
    absolute () const
    {
      if (empty ())
        throw std::logic_error ("empty location");

      // Note that in remote locations path is always relative.
      //
      return path_.absolute ();
    }

    bool
    relative () const
    {
      return local () && path_.relative ();
    }

    const butl::dir_path&
    path () const
    {
      if (empty ())
        throw std::logic_error ("empty location");

      return path_;
    }

    const std::string&
    host () const
    {
      if (local ())
        throw std::logic_error ("local location");

      return host_;
    }

    // Value 0 indicated that no port was specified explicitly.
    //
    std::uint16_t
    port () const
    {
      if (local ())
        throw std::logic_error ("local location");

      return port_;
    }

    enum class protocol {http, https};

    protocol
    proto () const
    {
      if (local ())
        throw std::logic_error ("local location");

      return proto_;
    }

    // Note that this is not necessarily syntactically the same string
    // as what was used to initialize this location. But it should be
    // semantically equivalent. String representation of an empty
    // location is the empty string.
    //
    std::string
    string () const;

  private:
    std::string canonical_name_;
    protocol proto_;
    std::string host_;
    std::uint16_t port_;
    butl::dir_path path_;
  };

  inline std::ostream&
  operator<< (std::ostream& os, const repository_location& l)
  {
    return os << l.string ();
  }

  enum class repository_role
  {
    base,
    prerequisite,
    complement
  };

  class LIBBPKG_EXPORT repository_manifest
  {
  public:
    using email_type = bpkg::email;

    repository_location location;
    butl::optional<repository_role> role;

    // The following values may only be present for the base repository.
    //
    butl::optional<std::string> url;
    butl::optional<email_type> email;
    butl::optional<std::string> summary;
    butl::optional<std::string> description;
    butl::optional<std::string> certificate;

    // Return the effective role of the repository. If the role is not
    // explicitly specified (see the role member above), then calculate
    // the role based on the location. Specifically, if the location is
    // empty, then the effective role is base. Otherwise -- prerequisite.
    // If the role is specified, then verify that it is consistent with
    // the location value (that is, base if the location is empty and
    // prerequisite or complement if not) and return that. Otherwise,
    // throw std::logic_error.
    //
    repository_role
    effective_role () const;

    // Return the effective web interface URL based on the specified remote
    // repository location. If url is not present or doesn't start with '.',
    // then return it unchanged. Otherwise, process the relative format
    // as described in the manifest specification. Throw std::invalid_argument
    // if the relative url format is invalid or if the repository location is
    // empty or local.
    //
    butl::optional<std::string>
    effective_url (const repository_location&) const;

  public:
    repository_manifest () = default; // VC export.
    repository_manifest (butl::manifest_parser&, bool ignore_unknown = false);
    repository_manifest (butl::manifest_parser&,
                         butl::manifest_name_value start,
                         bool ignore_unknown = false);

    void
    serialize (butl::manifest_serializer&) const;
  };

  class LIBBPKG_EXPORT repository_manifests:
    public std::vector<repository_manifest>
  {
  public:
    using base_type = std::vector<repository_manifest>;

    using base_type::base_type;

    repository_manifests () = default;
    repository_manifests (butl::manifest_parser&, bool ignore_unknown = false);

    void
    serialize (butl::manifest_serializer&) const;
  };

  class LIBBPKG_EXPORT signature_manifest
  {
  public:
    // Checksum of the corresponding package_manifests.
    //
    std::string sha256sum;

    // Signature of the corresponding package_manifests. Calculated by
    // encrypting package_manifests checksum (stored in sha256sum) with the
    // repository certificate private key.
    //
    std::vector<char> signature;

  public:
    signature_manifest () = default;
    signature_manifest (butl::manifest_parser&, bool ignore_unknown = false);

    // Serialize sha256sum and base64-encoded representation of the signature.
    //
    void
    serialize (butl::manifest_serializer&) const;

  private:
    // Used for delegating in public constructor. Strictly speaking is not
    // required, as a signature_manifest currently never appears as a part of
    // a manifest list, but kept for the consistency with other manifests
    // implementations.
    //
    signature_manifest (butl::manifest_parser&,
                        butl::manifest_name_value start,
                        bool ignore_unknown);
  };
}

#endif // BPKG_MANIFEST