//
//  ConfigurationBuilder.swift
//  LunarDatePicker
//
//  Service for building picker configurations
//

import Foundation

final class ConfigurationBuilder: ConfigurationProviding {

  // MARK: - ConfigurationProviding

  func buildPickerConfig(
    from params: LDP_PresentParams,
    globalConfig: LDP_ConfigParams?
  ) -> PickerConfig {
    var pickerConfig = PickerConfig.default

    // Apply basic configuration
    pickerConfig.controller.title = params.title
    pickerConfig.controller.fromText = params.fromText
    pickerConfig.controller.toText = params.toText
    pickerConfig.controller.submitText = params.submitText
    pickerConfig.controller.notSelectedText = params.notSelectedText
    pickerConfig.controller.showHeader = params.showHeader ?? true
    pickerConfig.controller.isSingleMode = (params.mode == LDP_Mode.single)

    // Apply theme if available
    if let globalConfig = globalConfig,
      let theme = globalConfig.themes[params.theme]
    {
      applyTheme(theme, to: &pickerConfig)
    }

    // Apply language if available
    if let globalConfig = globalConfig,
      let language = globalConfig.languages[params.language]
    {
      applyLanguage(language, to: &pickerConfig)
    }

    // Apply timezone if available
    if let timeZoneOffset = globalConfig?.timeZoneOffset {
      applyTimeZone(timeZoneOffset, to: &pickerConfig)
    }

    // Apply year range if available
    if let yearRangeOffset = globalConfig?.yearRangeOffset {
      applyYearRange(yearRangeOffset, to: &pickerConfig)
    }

    // Apply images if available in globalConfig
    if let globalConfig = globalConfig {
      pickerConfig.controller.fromImage = globalConfig.fromImage
      pickerConfig.controller.toImage = globalConfig.toImage
      pickerConfig.controller.closeImage = globalConfig.closeImage
      pickerConfig.controller.showSubmitButton = globalConfig.showSubmitButton
    }

    return pickerConfig
  }

  func applyTheme(_ theme: LDP_CustomStyle, to config: inout PickerConfig) {
    // Controller colors
    config.controller.backgroundColor = ColorWrapper(
      fromHex: theme.backgroundColor
    )
    config.controller.cancelColor = ColorWrapper(fromHex: theme.cancelColor)
    config.controller.titleColor = ColorWrapper(fromHex: theme.titleColor)
    config.controller.secondaryTextColor = ColorWrapper(fromHex: theme.secondColor)
    config.controller.borderColor = ColorWrapper(fromHex: theme.borderColor)

    // Day cell colors
    config.dayCell.dateLabelColor = ColorWrapper(fromHex: theme.dateLabelColor)
    config.dayCell.todayLabelColor = ColorWrapper(fromHex: theme.todayLabelColor)
    config.dayCell.weekendLabelColor = ColorWrapper(
      fromHex: theme.weekendLabelColor
    )
    config.dayCell.lunarDateLabelColor = ColorWrapper(
      fromHex: theme.lunarDateLabelColor
    )
    config.dayCell.specialDateLabelColor = ColorWrapper(
      fromHex: theme.specialDayLabelColor
    )
    config.dayCell.rangeBackgroundColor = ColorWrapper(
      fromHex: theme.rangeBackgroundColor
    )
    config.dayCell.selectedBackgroundColor = ColorWrapper(
      fromHex: theme.selectedBackgroundColor
    )
    config.dayCell.selectedTextColor = ColorWrapper(
      fromHex: theme.selectedTextColor
    )

    // Month header colors
    config.monthHeader.labelColor = ColorWrapper(fromHex: theme.monthLabelColor)

    // Week view colors
    config.weekView.backgroundColor = ColorWrapper(
      fromHex: theme.weekViewBackgroundColor
    )
    config.weekView.weekendLabelColor = ColorWrapper(
      fromHex: theme.weekendLabelColor
    )
    config.weekView.weekLabelColor = ColorWrapper(fromHex: theme.dateLabelColor)

    // Confirm button gradient colors (always provided by TS)
    config.controller.confirmGradientColors = theme.gradientColors.map { ColorWrapper(fromHex: $0) }
  }

  func applyLanguage(_ language: LDP_CustomLanguage, to config: inout PickerConfig)
  {
    config.weekView.weekdayNames = language.weekdayNames
    // Apply locale for all native date formatting
    config.calendar.locale = Locale(identifier: language.locale)
  }

  func applyTimeZone(_ offset: Double, to config: inout PickerConfig) {
    config.calendar.timeZone =
      TimeZone(secondsFromGMT: Int(offset * 3600)) ?? TimeZone.current
  }

  func applyYearRange(_ offset: Double, to config: inout PickerConfig) {
    config.yearRangeOffset = Int(offset)
  }
}