// 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

// MARK: - JSON Export/Import Structures
struct UserPreferencesJSON: Codable {
  // MARK: - Map Preferences
  var showMapBackground: Bool?
  var useCustomFont: Bool?
  var customFontName: String?
  var defaultExportFormat: String?
  var useSmartLabelPositioning: Bool?

  // MARK: - Editor Preferences
  var useSmartEditor: Bool?
  var useCustomEditorFont: Bool?
  var customEditorFontName: String?
  var editorFontSize: Double?
  var softWrapLines: Bool?

  // MARK: - Templates (as actual objects)
  var mapTemplates: [Template]?

  // MARK: - Stages (as actual objects)
  var customStages: [CustomStage]?

  // MARK: - UI Preferences
  var viewStyle: String?
  var zoom: Double?
}

struct UserPreferences: Codable {

  // MARK: - Map Preferences
  var showMapBackground: Bool
  var useCustomFont: Bool
  var customFontName: String
  var defaultExportFormat: String
  var useSmartLabelPositioning: Bool

  // MARK: - Editor Preferences
  var useSmartEditor: Bool
  var useCustomEditorFont: Bool
  var customEditorFontName: String
  var editorFontSize: Double
  var softWrapLines: Bool

  // MARK: - Templates
  var mapTemplates: Data

  // MARK: - Stages
  var customStages: Data

  // MARK: - UI Preferences
  var viewStyle: String
  var zoom: Double

  // MARK: - Default Values
  struct Defaults {
    static let showMapBackground = true
    static let useCustomFont = false
    static let customFontName = "Helvetica"
    static let defaultExportFormat = "png"
    static let useSmartLabelPositioning = true

    static let useSmartEditor = false
    static let useCustomEditorFont = false
    static let customEditorFontName = "Menlo"
    static let editorFontSize = 14.0
    static let softWrapLines = false

    static let viewStyle = "horizontal"
    static let zoom = 1.0

    // Computed properties for complex defaults
    static var mapTemplates: Data {
      let defaultTemplate = Template(
        name: String(localized: "map_template.default.title"),
        content: String(localized: "map_template.default.content"),
        isDefault: true
      )

      let emptyTemplate = Template(
        name: String(localized: "map_template.empty.title"),
        content: "",
        isDefault: false
      )

      let templates = [defaultTemplate, emptyTemplate]
      return (try? JSONEncoder().encode(templates)) ?? Data()
    }

    static var customStages: Data {
      let defaultStage = CustomStage.cynefinDefault()
      let stages = [defaultStage]
      return (try? JSONEncoder().encode(stages)) ?? Data()
    }
  }

  // MARK: - Initialization
  init() {
    self.showMapBackground = Defaults.showMapBackground
    self.useCustomFont = Defaults.useCustomFont
    self.customFontName = Defaults.customFontName
    self.defaultExportFormat = Defaults.defaultExportFormat
    self.useSmartLabelPositioning = Defaults.useSmartLabelPositioning

    self.useSmartEditor = Defaults.useSmartEditor
    self.useCustomEditorFont = Defaults.useCustomEditorFont
    self.customEditorFontName = Defaults.customEditorFontName
    self.editorFontSize = Defaults.editorFontSize
    self.softWrapLines = Defaults.softWrapLines

    self.mapTemplates = Defaults.mapTemplates
    self.customStages = Defaults.customStages

    self.viewStyle = Defaults.viewStyle
    self.zoom = Defaults.zoom
  }

  // MARK: - JSON Methods
  func toJSON() -> String? {
    let encoder = JSONEncoder()
    encoder.outputFormatting = .prettyPrinted

    do {
      // Convert to JSON-friendly format
      let jsonPrefs = UserPreferencesJSON(
        showMapBackground: showMapBackground,
        useCustomFont: useCustomFont,
        customFontName: customFontName,
        defaultExportFormat: defaultExportFormat,
        useSmartLabelPositioning: useSmartLabelPositioning,
        useSmartEditor: useSmartEditor,
        useCustomEditorFont: useCustomEditorFont,
        customEditorFontName: customEditorFontName,
        editorFontSize: editorFontSize,
        softWrapLines: softWrapLines,
        mapTemplates: templatesFromData(mapTemplates),
        customStages: stagesFromData(customStages),
        viewStyle: viewStyle,
        zoom: zoom
      )

      let data = try encoder.encode(jsonPrefs)
      return String(data: data, encoding: .utf8)
    } catch {
      return nil
    }
  }

  mutating func updateFromJSON(_ json: String) -> Bool {
    guard let data = json.data(using: .utf8) else { return false }
    do {
      let decoder = JSONDecoder()
      let jsonPrefs = try decoder.decode(UserPreferencesJSON.self, from: data)

      // Convert from JSON format back to UserPreferences
      // Only update values that are present in the JSON (partial updates)
      if let value = jsonPrefs.showMapBackground {
        self.showMapBackground = value
      }
      if let value = jsonPrefs.useCustomFont {
        self.useCustomFont = value
      }
      if let value = jsonPrefs.customFontName {
        self.customFontName = value
      }
      if let value = jsonPrefs.defaultExportFormat {
        self.defaultExportFormat = value
      }
      if let value = jsonPrefs.useSmartLabelPositioning {
        self.useSmartLabelPositioning = value
      }
      if let value = jsonPrefs.useSmartEditor {
        self.useSmartEditor = value
      }
      if let value = jsonPrefs.useCustomEditorFont {
        self.useCustomEditorFont = value
      }
      if let value = jsonPrefs.customEditorFontName {
        self.customEditorFontName = value
      }
      if let value = jsonPrefs.editorFontSize {
        self.editorFontSize = value
      }
      if let value = jsonPrefs.softWrapLines {
        self.softWrapLines = value
      }
      if let value = jsonPrefs.mapTemplates {
        self.mapTemplates = dataFromTemplates(value)
      }
      if let value = jsonPrefs.customStages {
        self.customStages = dataFromStages(value)
      }
      if let value = jsonPrefs.viewStyle {
        self.viewStyle = value
      }
      if let value = jsonPrefs.zoom {
        self.zoom = value
      }

      apply()
      return true
    } catch {
      print("JSON import error: \(error)")
      return false
    }
  }

  // MARK: - Helper Methods for Data/Object Conversion
  private func templatesFromData(_ data: Data) -> [Template] {
    guard let templates = try? JSONDecoder().decode([Template].self, from: data) else {
      return []
    }
    return templates
  }

  private func dataFromTemplates(_ templates: [Template]) -> Data {
    guard let data = try? JSONEncoder().encode(templates) else {
      return Data()
    }
    return data
  }

  private func stagesFromData(_ data: Data) -> [CustomStage] {
    guard let stages = try? JSONDecoder().decode([CustomStage].self, from: data) else {
      return []
    }
    return stages
  }

  private func dataFromStages(_ stages: [CustomStage]) -> Data {
    guard let data = try? JSONEncoder().encode(stages) else {
      return Data()
    }
    return data
  }

  // MARK: - Reset to Defaults
  mutating func resetToDefaults() {
    self = UserPreferences()
    apply()
  }

  // MARK: - Apply to UserDefaults
  private func apply() {
    let defaults = UserDefaults.standard

    // Map Preferences
    defaults.set(showMapBackground, forKey: "showMapBackground")
    defaults.set(useCustomFont, forKey: "useCustomFont")
    defaults.set(customFontName, forKey: "customFontName")
    defaults.set(defaultExportFormat, forKey: "defaultExportFormat")
    defaults.set(useSmartLabelPositioning, forKey: "useSmartLabelPositioning")

    // Editor Preferences
    defaults.set(useSmartEditor, forKey: "useSmartEditor")
    defaults.set(useCustomEditorFont, forKey: "useCustomEditorFont")
    defaults.set(customEditorFontName, forKey: "customEditorFontName")
    defaults.set(editorFontSize, forKey: "editorFontSize")
    defaults.set(softWrapLines, forKey: "softWrapLines")

    // Templates
    defaults.set(mapTemplates, forKey: "mapTemplates")

    // Stages
    defaults.set(customStages, forKey: "customStages")

    // UI Preferences
    defaults.set(viewStyle, forKey: "viewStyle")
    defaults.set(zoom, forKey: "zoom")
  }

  // MARK: - Load from UserDefaults
  static func loadFromUserDefaults() -> UserPreferences {
    let defaults = UserDefaults.standard

    var preferences = UserPreferences()

    // Map Preferences
    preferences.showMapBackground =
      defaults.object(forKey: "showMapBackground") as? Bool ?? Defaults.showMapBackground
    preferences.useCustomFont =
      defaults.object(forKey: "useCustomFont") as? Bool ?? Defaults.useCustomFont
    preferences.customFontName =
      defaults.object(forKey: "customFontName") as? String ?? Defaults.customFontName
    preferences.defaultExportFormat =
      defaults.object(forKey: "defaultExportFormat") as? String ?? Defaults.defaultExportFormat
    preferences.useSmartLabelPositioning =
      defaults.object(forKey: "useSmartLabelPositioning") as? Bool
      ?? Defaults.useSmartLabelPositioning

    // Editor Preferences
    preferences.useSmartEditor =
      defaults.object(forKey: "useSmartEditor") as? Bool ?? Defaults.useSmartEditor
    preferences.useCustomEditorFont =
      defaults.object(forKey: "useCustomEditorFont") as? Bool ?? Defaults.useCustomEditorFont
    preferences.customEditorFontName =
      defaults.object(forKey: "customEditorFontName") as? String ?? Defaults.customEditorFontName
    preferences.editorFontSize =
      defaults.object(forKey: "editorFontSize") as? Double ?? Defaults.editorFontSize
    preferences.softWrapLines =
      defaults.object(forKey: "softWrapLines") as? Bool ?? Defaults.softWrapLines

    // Templates
    preferences.mapTemplates =
      defaults.object(forKey: "mapTemplates") as? Data ?? Defaults.mapTemplates

    // Stages
    preferences.customStages =
      defaults.object(forKey: "customStages") as? Data ?? Defaults.customStages

    // UI Preferences
    preferences.viewStyle = defaults.object(forKey: "viewStyle") as? String ?? Defaults.viewStyle
    preferences.zoom = defaults.object(forKey: "zoom") as? Double ?? Defaults.zoom

    return preferences
  }
}