import CoreGraphics
import Foundation

// MARK: - Types

struct MapParsingPatterns {
  static let vertex = try! NSRegularExpression(
    pattern:
      "([^\\(]+?)[\\s]*\\([\\s]*([0-9]+.?[0-9]*)[\\s]*,[\\s]*([0-9]+.?[0-9]*)[\\s]*\\)[\\s]*(?:\\[(.*?)\\])?",
    options: .caseInsensitive)
  static let edge = try! NSRegularExpression(
    pattern: "(.+?)[\\s]*-([->])[\\s]*(.+)", options: .caseInsensitive)
  static let blocker = try! NSRegularExpression(
    pattern: "\\[(Blocker)\\][\\s]*(.+)", options: .caseInsensitive)
  static let opportunity = try! NSRegularExpression(
    pattern: "\\[(Opportunity)\\][\\s]*(.+)[\\s]+([-+])[\\s]*([0-9]+.?[0-9]*)",
    options: .caseInsensitive)
  static let stage = try! NSRegularExpression(
    pattern: "\\[(I{1,3})\\][\\s]*([0-9]+.?[0-9]*)", options: .caseInsensitive)
}

struct ParsedMap {
  let vertices: [Vertex]
  let edges: [MapEdge]
  let blockers: [Blocker]
  let opportunities: [Opportunity]
  let stages: [CGFloat]
}

struct Vertex {
  let id: Int
  let label: String
  let position: CGPoint
  var shape: VertexShape = .circle
}

enum VertexShape: String {
  case circle
  case square
  case triangle
  case x
}

struct MapEdge {
  let id: Int
  let origin: CGPoint
  let destination: CGPoint
  let arrowhead: Bool
}

struct Blocker {
  let id: Int
  let position: CGPoint
}

struct Opportunity {
  let id: Int
  let origin: CGPoint
  let destination: CGPoint
}

struct StageDimensions {
  let index: Int
  let dimensions: CGFloat
}

private let defaultDimensions: [CGFloat] = [
  25.0,
  50.0,
  75.0,
]

// MARK: - MapParserStrategy protocol

protocol MapParserStrategy {
  func canHandle(line: String) -> Bool
  func handle(index: Int, line: String, vertices: [String: Vertex]) -> (Any.Type, Any)
}

struct AnyMapParserStrategy: MapParserStrategy {

  private let base: MapParserStrategy

  init<T: MapParserStrategy>(_ base: T) {
    self.base = base
  }

  func canHandle(line: String) -> Bool {
    return base.canHandle(line: line)
  }
  func handle(index: Int, line: String, vertices: [String: Vertex]) -> (Any.Type, Any) {
    return base.handle(index: index, line: line, vertices: vertices)
  }
}

// MARK: - Map Builder

class MapBuilder {
  var vertices: [String: Vertex] = [:]
  private var edges: [MapEdge] = []
  private var blockers: [Blocker] = []
  private var opportunities: [Opportunity] = []
  private var stages: [CGFloat] = defaultDimensions

  func addObjectToMap(type: Any.Type, object: Any) {
    if type == Vertex.self {
      let vertex = object as! Vertex
      vertices[vertex.label] = vertex
    }

    if type == MapEdge.self {
      let edge = object as! MapEdge
      edges.append(edge)
    }

    if type == Blocker.self {
      let blocker = object as! Blocker
      blockers.append(blocker)
    }

    if type == Opportunity.self {
      let opportunity = object as! Opportunity
      opportunities.append(opportunity)
    }

    if type == StageDimensions.self {
      let stageDimensions = object as! StageDimensions
      stages[stageDimensions.index] = stageDimensions.dimensions

    }
  }

  func build() -> ParsedMap {
    let mappedVertices = vertices.map { label, vertex in return vertex }
    return ParsedMap(
      vertices: mappedVertices, edges: edges, blockers: blockers, opportunities: opportunities,
      stages: stages)
  }
}