/*

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 */

#ifndef HERMES_SUPPORT_SOURCEMAPPARSER_H

#define HERMES_SUPPORT_SOURCEMAPPARSER_H

#include "hermes/SourceMap/SourceMapGenerator.h"

#include "llvh/Support/MemoryBuffer.h"

namespace hermes {

/// JavaScript version 3 source map parser.

/// See https://sourcemaps.info/spec.html for the spec that this class

/// parses.

class SourceMapParser {

 public:

  /// Parse input \p sourceMap and return parsed SourceMap.

  /// On failure if malformed, prints an error message and returns nullptr.

  static std::unique_ptr<SourceMap> parse(

      llvh::MemoryBufferRef sourceMap,

      SourceErrorManager &sm);

  /// Parse input \p sourceMapContent and return parsed SourceMap.

  /// Set the filename of the map file to "<source map>".

  /// On failure if malformed, prints an error message and returns nullptr.

  static std::unique_ptr<SourceMap> parse(

      llvh::StringRef sourceMapContent,

      SourceErrorManager &sm) {

    return parse(llvh::MemoryBufferRef(sourceMapContent, "<source map>"), sm);

  }

 private:

  SourceMapParser() = delete;

  SourceMapParser(SourceMapParser &) = delete;

  SourceMapParser(SourceMapParser &&) = delete;

  SourceMapParser &operator=(SourceMapParser &) = delete;

  SourceMapParser &operator=(SourceMapParser &&) = delete;

  /// Delta encoding state.

  struct State {

    int32_t generatedColumn = 0;

    int32_t sourceIndex = 0;

    int32_t representedLine = 0;

    int32_t representedColumn = 0;

    int32_t nameIndex = 0;

  };

  /// Parse "mappings" section from \p sourceMappings. The parsed line mappings

  /// are returned in \p lines.

  static bool parseMappings(

      llvh::StringRef sourceMappings,

      std::vector<SourceMap::SegmentList> &lines);

  /// Parse single segment in mapping.

  static llvh::Optional<SourceMap::Segment>

  parseSegment(const State &state, const char *&pCur, const char *pSegEnd);

};

} // namespace hermes

#endif // HERMES_SUPPORT_SOURCEMAPPARSER_H