// 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 SwiftUI
import UniformTypeIdentifiers
import WmapParser

struct MapDocument: FileDocument {
  var text: String

  init(
    text: String? = nil
  ) {
    if let text = text {
      self.text = text
    } else {
      // Check for pending template content first
      if let pendingContent = UserDefaults.standard.string(forKey: "pendingTemplateContent") {
        self.text = pendingContent
      } else if let templatesData = UserDefaults.standard.data(forKey: "mapTemplates"),
        let templates = try? JSONDecoder().decode([Template].self, from: templatesData),
        let defaultTemplate = templates.first(where: { $0.isDefault }) {
        self.text = defaultTemplate.content
      } else {
        self.text = String(localized: "map_template.default.content")
      }
    }
  }

  static var readableContentTypes: [UTType] { [.wmap] }

  var parsed: WmapParser.Map {
    return WmapParser.parse(self.text)
  }

  init(configuration: ReadConfiguration) throws {
    guard let data = configuration.file.regularFileContents,
      let string = String(data: data, encoding: .utf8)
    else {
      throw CocoaError(.fileReadCorruptFile)
    }
    text = string
  }

  func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper {
    let data = text.data(using: .utf8)!
    return .init(regularFileWithContents: data)
  }

  @MainActor
  func exportAsImage(withEvolution selectedEvolution: StageType) -> NSImage? {
    let renderableMap = RenderableMap.from(self.parsed)
    let mapSize = Dimensions.Map.size
    let vertexSize = CGSize(width: 25.0, height: 25.0)
    let useSmartLabels = UserDefaults.standard.bool(forKey: "useSmartLabelPositioning")

    var labelPositions: [Int: CGPoint] = [:]
    if useSmartLabels {
      let axisLines = [
        Line(start: CGPoint(x: 0, y: 0), end: CGPoint(x: 0, y: mapSize.height)),
        Line(
          start: CGPoint(x: 0, y: mapSize.height),
          end: CGPoint(x: mapSize.width, y: mapSize.height)),
      ]
      for vertex in renderableMap.vertices {
        labelPositions[vertex.id] = SmartLabelPositioning.calculateOptimalLabelPosition(
          for: vertex, mapSize: mapSize, vertexSize: vertexSize,
          edges: renderableMap.edges, opportunities: renderableMap.opportunities,
          inertias: renderableMap.inertias, axisLines: axisLines,
          allVertices: renderableMap.vertices, notes: renderableMap.notes)
      }
    }

    let renderView = MapRenderView(
      parsedMap: self.parsed,
      evolution: .constant(selectedEvolution),
      precomputedMap: renderableMap,
      precomputedLabelPositions: labelPositions)
    let renderer = ImageRenderer(content: renderView)

    return renderer.nsImage
  }
}