// SPDX-License-Identifier: Apache-2.0

// SPDX-FileCopyrightText: Copyright The WasmEdge Authors

#pragma once

#include "common/errcode.h"

#include "common/expected.h"

#include <cstdint>

#include <string_view>

namespace WasmEdge {

namespace Validator {

namespace Component {

/// A parsed extern name of a component import or export.

class ExternName {

public:

  enum class Kind : uint8_t {

    Invalid,

    Constructor,

    Method,

    Static,

    InterfaceType,

    Label,

    LockedDep,

    UnlockedDep,

    Url,

    Integrity

  };

  /// Fragments as views into the input; the kind decides which are set.

  struct Detail {

    std::string_view Resource;     // Constructor, Method, Static

    std::string_view Method;       // Method, Static

    std::string_view Namespace;    // InterfaceType, LockedDep, UnlockedDep

    std::string_view Package;      // InterfaceType, LockedDep, UnlockedDep

    std::string_view Interface;    // InterfaceType

    std::string_view Version;      // InterfaceType, LockedDep

    std::string_view VersionRange; // UnlockedDep

    std::string_view Url;          // Url

    std::string_view Integrity;    // LockedDep, Url, Integrity

  };

  /// Returns true if Input is a label: <first-fragment> ( '-' <fragment> )*.

  static bool isKebabString(std::string_view Input) noexcept;

  /// Parses Name into this object, which stays Invalid on failure.

  Expect<void> parse(std::string_view Name) noexcept;

  Kind getKind() const noexcept { return NameKind; }

  std::string_view getOriginalName() const noexcept { return OriName; }

  /// The name without its annotation tag; empty when the name carries none.

  std::string_view getNoTagName() const noexcept { return NoTagName; }

  const Detail &getDetail() const noexcept { return NameDetail; }

  /// The `versionsuffix` attribute: canonversion plus Suffix must be a semver.

  Expect<void> checkVersionSuffix(std::string_view Suffix) const noexcept;

private:

  // Cursor primitives, all consuming from Rest.

  bool tryRead(std::string_view Prefix) noexcept;

  bool readUntil(char Delim, std::string_view &Output) noexcept;

  std::string_view readLabelChars() noexcept;

  // One member per production, consuming the rest after its leading tag.

  Expect<void> parsePlainName() noexcept;

  Expect<void> parseUnlockedDep() noexcept;

  Expect<void> parseLockedDep() noexcept;

  Expect<void> parseUrlName() noexcept;

  Expect<void> parseHashName() noexcept;

  Expect<void> parseInterfaceName() noexcept;

  Expect<void> parsePkgPath(std::string_view StopChars) noexcept;

  Expect<std::string_view> parseIntegrityBody() noexcept;

  Expect<std::string_view> parseIntegritySuffix() noexcept;

  // Grammar checks over a substring; the semver scanners stay unlogged.

  Expect<void> checkWordsLabel(std::string_view Label,

                               std::string_view What) const noexcept;

  Expect<void> checkVersionRange(std::string_view Body) const noexcept;

  bool isCanonVersion(std::string_view V) const noexcept;

  Expect<void> scanSemver(std::string_view V) const noexcept;

  Expect<void> scanSemverIdentifiers(std::string_view Idents,

                                     bool CheckLeadingZeros) const noexcept;

  Expect<void> checkIntegrityMetadata(std::string_view Input) const noexcept;

  std::string_view OriName;

  std::string_view NoTagName;

  std::string_view Rest;

  Kind NameKind = Kind::Invalid;

  Detail NameDetail;

};

} // namespace Component

} // namespace Validator

} // namespace WasmEdge