// Copyright (C) 2024 Rubén Beltrán del Río

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program. If not, see https://map.tranquil.systems.
import Foundation

struct GroupParserStrategy: MapParserStrategy {
  private let regex = MapParsingPatterns.group

  func canHandle(line: String) -> Bool {
    let range = NSRange(location: 0, length: line.utf16.count)
    let matches = regex.matches(in: String(line), options: [], range: range)
    return matches.count > 0 && matches[0].numberOfRanges == 3
  }

  func handle(index: Int, line: String, vertices: [String: Vertex]) -> (Any.Type, Any) {
    let range = NSRange(location: 0, length: line.utf16.count)
    let matches = regex.matches(in: String(line), options: [], range: range)

    let match = matches[0]
    var groupVertices: [Vertex] = []
    let vertexIdString = String(line[Range(match.range(at: 2), in: line)!])
    let vertexIds = vertexIdString.split(separator: ",", omittingEmptySubsequences: true).map(
      String.init
    ).map({ vertexId in
      vertexId.trimmingCharacters(in: .whitespacesAndNewlines)
    })

    for vertexId in vertexIds {
      if let vertex = vertices[vertexId] {
        groupVertices.append(vertex)
      }
    }

    if groupVertices.count > 0 {
      return ([Vertex].self, groupVertices)
    }

    return (NSObject.self, NSObject())
  }
}