//
//  ContentView.swift
//  Map
//
//  Created by Ruben Beltran del Rio on 2/1/21.
//

import SwiftUI
import CoreData
import CoreGraphics

struct MapRenderView: View {
    @ObservedObject var map: Map
    let evolution: Stage
    
    let VERTEX_SIZE = CGSize(width: 25.0, height: 25.0)
    let ARROWHEAD_SIZE = CGFloat(10.0)
    let LINE_WIDTH = CGFloat(1.0)
    let PADDING = CGFloat(4.0)
    let STAGE_FRAME = CGSize(width: 245, height: 50)
    
    var parsedMap: ParsedMap {
        return map.parse()
    }

    var body: some View {
        ZStack(alignment: .topLeading) {
            ZStack (alignment: .topLeading) {
            // The Axes
            Path { path in
                path.move(to: CGPoint(x: 0, y: 0))
                path.addLine(to: CGPoint(x: 0, y: 1000))
                path.addLine(to: CGPoint(x: 1000, y: 1000))
                path.move(to: CGPoint(x: 1000, y: 1000))
                path.closeSubpath()
                
            }.strokedPath(StrokeStyle(lineWidth: LINE_WIDTH * 2))
            Text("Visible").font(.title3).rotationEffect(Angle(degrees: -90.0)).offset(CGSize(width: -35.0, height: 0.0))
            Text("Value Chain").font(.title).rotationEffect(Angle(degrees: -90.0)).offset(CGSize(width: -72.0, height: 480.0))
            Text("Invisible").font(.title3).rotationEffect(Angle(degrees: -90.0)).offset(CGSize(width: -40.0, height: 980.0))
                Text(evolution.I).font(.title3).frame(width: STAGE_FRAME.width, height: STAGE_FRAME.height, alignment: .topLeading).offset(CGSize(width: 0.0, height: 1000.0))
                Text(evolution.II).font(.title3).frame(width: STAGE_FRAME.width, height: STAGE_FRAME.height, alignment: .topLeading).offset(CGSize(width: 250.0, height: 1000.0))
            Text(evolution.III).font(.title3).frame(width: STAGE_FRAME.width, height: STAGE_FRAME.height, alignment: .topLeading).offset(CGSize(width: 500.0, height: 1000.0))
            Text(evolution.IV).font(.title3).frame(width: STAGE_FRAME.width, height: STAGE_FRAME.height, alignment: .topLeading).offset(CGSize(width: 750.0, height: 1000.0))
            }.offset(CGSize(width: 0.0, height: 0.0))
            
            // The Lanes
            Path { path in
                path.move(to: CGPoint(x: 250, y: 0))
                path.addLine(to: CGPoint(x: 250, y: 1000))
                path.move(to: CGPoint(x: 500, y: 0))
                path.addLine(to: CGPoint(x: 500, y: 1000))
                path.move(to: CGPoint(x: 750, y: 0))
                path.addLine(to: CGPoint(x: 750, y: 1000))
                path.move(to: CGPoint(x: 250, y: 0))
                path.closeSubpath()
            }.strokedPath(StrokeStyle(lineWidth: LINE_WIDTH, dash: [10.0]))
            
            Path { path in
                path.addRect(CGRect(x: 0, y: 0, width: 250, height: 1000))
            }.fill(Color.red).opacity(0.1)
            Path { path in
                path.addRect(CGRect(x: 250, y: 0, width: 250, height: 1000))
            }.fill(Color.orange).opacity(0.1)
            Path { path in
                path.addRect(CGRect(x: 500, y: 0, width: 250, height: 1000))
            }.fill(Color.yellow).opacity(0.1)
            Path { path in
                path.addRect(CGRect(x: 750, y: 0, width: 250, height: 1000))
            }.fill(Color.green).opacity(0.1)
            
            // The Vertices
            
            ForEach(parsedMap.vertices, id: \.id) { vertex in
                Path { path in
                        path.addEllipse(in: CGRect(
                            origin: vertex.position, size: VERTEX_SIZE
                        ))
                }
                Text(vertex.label).foregroundColor(Color.gray).offset(CGSize(
                                        width: vertex.position.x + VERTEX_SIZE.width + PADDING,
                                        height: vertex.position.y))
            }
            
            // The Edges
            
            ForEach(parsedMap.edges, id: \.id) { edge in
                Path { path in
                    
                    let slope = (edge.destination.y - edge.origin.y) / (edge.destination.x - edge.origin.x)
                    let angle = atan(slope)
                    let multiplier = CGFloat(slope < 0 ? -1.0 : 1.0)
                    let upperAngle = angle - CGFloat.pi / 4.0
                    let lowerAngle = angle + CGFloat.pi / 4.0
                    
                    let offsetOrigin = CGPoint(x: edge.origin.x + multiplier * (VERTEX_SIZE.width / 2.0) * cos(angle), y: edge.origin.y + multiplier * (VERTEX_SIZE.height / 2.0) * sin(angle))
                    let offsetDestination = CGPoint(x: edge.destination.x - multiplier * (VERTEX_SIZE.width / 2.0) * cos(angle), y: edge.destination.y - multiplier * (VERTEX_SIZE.height / 2.0) * sin(angle))
                    
                        path.move(to: offsetOrigin)
                        path.addLine(to: offsetDestination)
                    
                    // Arrowheads
                        path.move(to: offsetDestination)
                    path.addLine(to: CGPoint(x: offsetDestination.x - multiplier * ARROWHEAD_SIZE * cos(upperAngle), y:
                                                offsetDestination.y - multiplier * ARROWHEAD_SIZE * sin(upperAngle)))
                    
                    path.move(to: offsetDestination)
                    path.addLine(to: CGPoint(x: offsetDestination.x - multiplier * ARROWHEAD_SIZE * cos(lowerAngle), y:
                                                offsetDestination.y - multiplier *  ARROWHEAD_SIZE * sin(lowerAngle)))
                    path.move(to: offsetDestination)
                        path.closeSubpath()
                }.applying(CGAffineTransform(translationX: VERTEX_SIZE.width / 2.0, y: VERTEX_SIZE.height / 2.0)).strokedPath(StrokeStyle(lineWidth: LINE_WIDTH))
            }
        }.frame(
            minWidth: 1050.0, maxWidth: .infinity,
            minHeight: 1050.0, maxHeight: .infinity, alignment: .topLeading
        ).padding(30.0)
    }
}

struct MapRenderView_Previews: PreviewProvider {
    static var previews: some View {
        MapDetailView(map: Map()).environment(\.managedObjectContext, PersistenceController.preview.container.viewContext)
    }
}