import CoreImage.CIFilterBuiltins
import SwiftUI

enum Theme {
  static let background = Color(red: 0.035, green: 0.035, blue: 0.05)
  static let surface = Color(red: 0.09, green: 0.09, blue: 0.12)
  static let surfaceAlt = Color(red: 0.13, green: 0.13, blue: 0.17)
  static let border = Color.white.opacity(0.08)
  static let accent = Color(red: 1.0, green: 0.56, blue: 0.16)
  static let accentSoft = Color(red: 1.0, green: 0.56, blue: 0.16).opacity(0.15)
  static let text = Color.white
  static let muted = Color.white.opacity(0.55)
  static let danger = Color(red: 1.0, green: 0.36, blue: 0.36)
  static let success = Color(red: 0.35, green: 0.85, blue: 0.55)
}

struct PrimaryButton: View {
  var title: String
  var disabled: Bool = false
  var action: () -> Void

  var body: some View {
    Button(action: action) {
      Text(title)
        .font(.system(size: 16, weight: .semibold))
        .frame(maxWidth: .infinity)
        .padding(.vertical, 15)
        .background(disabled ? Theme.surfaceAlt : Theme.accent)
        .foregroundStyle(disabled ? Theme.muted : Color.black)
        .clipShape(RoundedRectangle(cornerRadius: 14, style: .continuous))
    }
    .disabled(disabled)
  }
}

struct SecondaryButton: View {
  var title: String
  var action: () -> Void

  var body: some View {
    Button(action: action) {
      Text(title)
        .font(.system(size: 15, weight: .medium))
        .frame(maxWidth: .infinity)
        .padding(.vertical, 14)
        .background(Theme.surface)
        .foregroundStyle(Theme.text)
        .overlay(RoundedRectangle(cornerRadius: 14, style: .continuous).stroke(Theme.border))
        .clipShape(RoundedRectangle(cornerRadius: 14, style: .continuous))
    }
  }
}

struct Card<Content: View>: View {
  @ViewBuilder var content: Content

  var body: some View {
    content
      .padding(18)
      .frame(maxWidth: .infinity, alignment: .leading)
      .background(Theme.surface)
      .overlay(RoundedRectangle(cornerRadius: 20, style: .continuous).stroke(Theme.border))
      .clipShape(RoundedRectangle(cornerRadius: 20, style: .continuous))
  }
}

struct FieldLabel: View {
  var text: String

  var body: some View {
    Text(text)
      .font(.system(size: 12, weight: .medium))
      .foregroundStyle(Theme.muted)
      .padding(.leading, 4)
  }
}

struct KoinsTextField: View {
  var placeholder: String
  @Binding var text: String
  var multiline = false
  var keyboard: UIKeyboardType = .default
  var autocapitalization: TextInputAutocapitalization = .never

  var body: some View {
    Group {
      if multiline {
        TextEditor(text: $text)
          .scrollContentBackground(.hidden)
          .frame(minHeight: 96)
          .padding(8)
      } else {
        TextField(placeholder, text: $text)
          .keyboardType(keyboard)
          .textInputAutocapitalization(autocapitalization)
          .autocorrectionDisabled()
          .padding(.horizontal, 14)
          .padding(.vertical, 13)
      }
    }
    .font(.system(size: 15))
    .foregroundStyle(Theme.text)
    .background(Theme.surface)
    .overlay(RoundedRectangle(cornerRadius: 14, style: .continuous).stroke(Theme.border))
    .clipShape(RoundedRectangle(cornerRadius: 14, style: .continuous))
  }
}

struct MessageBanner: View {
  var message: String
  var isError: Bool

  var body: some View {
    Text(message)
      .font(.system(size: 13))
      .foregroundStyle(isError ? Theme.danger : Theme.success)
      .frame(maxWidth: .infinity, alignment: .leading)
      .padding(12)
      .background((isError ? Theme.danger : Theme.success).opacity(0.12))
      .clipShape(RoundedRectangle(cornerRadius: 12, style: .continuous))
  }
}

struct ChainPicker: View {
  @Binding var selection: Chain

  var body: some View {
    HStack(spacing: 6) {
      ForEach(Chain.allCases, id: \.self) { chain in
        Button {
          selection = chain
        } label: {
          Text(chain.title)
            .font(.system(size: 13, weight: .semibold))
            .frame(maxWidth: .infinity)
            .padding(.vertical, 10)
            .background(selection == chain ? Theme.accent : Color.clear)
            .foregroundStyle(selection == chain ? Color.black : Theme.muted)
            .clipShape(RoundedRectangle(cornerRadius: 10, style: .continuous))
        }
      }
    }
    .padding(4)
    .background(Theme.surface)
    .clipShape(RoundedRectangle(cornerRadius: 14, style: .continuous))
  }
}

struct QRCodeView: View {
  var text: String

  var body: some View {
    if let image = QRCodeView.makeImage(from: text) {
      Image(uiImage: image)
        .interpolation(.none)
        .resizable()
        .scaledToFit()
        .padding(12)
        .background(Color.white)
        .clipShape(RoundedRectangle(cornerRadius: 16, style: .continuous))
    } else {
      RoundedRectangle(cornerRadius: 16, style: .continuous)
        .fill(Theme.surfaceAlt)
        .aspectRatio(1, contentMode: .fit)
    }
  }

  private static func makeImage(from text: String) -> UIImage? {
    QRCodeImage.make(text)
  }
}

struct TransactionRow: View {
  var record: TransactionRecord
  var symbol: String

  private var subtitle: String {
    if let timestamp = record.timestamp {
      let formatter = DateFormatter()
      formatter.dateStyle = .medium
      formatter.timeStyle = .short
      return record.confirmed ? formatter.string(from: timestamp) : "Pending confirmation"
    }
    // Monero transfers carry no timestamp; the block height is the honest label.
    if let height = record.height, height > 0 {
      return record.confirmed ? "Block \(height)" : "In the transaction pool"
    }
    return record.confirmed ? "Confirmed" : "Pending"
  }

  var body: some View {
    HStack(spacing: 12) {
      ZStack {
        Circle()
          .fill(record.direction == .incoming ? Theme.success.opacity(0.15) : Theme.accentSoft)
          .frame(width: 38, height: 38)
        Image(systemName: record.direction == .incoming ? "arrow.down.left" : "arrow.up.right")
          .font(.system(size: 15, weight: .bold))
          .foregroundStyle(record.direction == .incoming ? Theme.success : Theme.accent)
      }

      VStack(alignment: .leading, spacing: 3) {
        Text(record.direction == .incoming ? "Received" : "Sent")
          .font(.system(size: 14, weight: .semibold))
          .foregroundStyle(Theme.text)
        Text(subtitle)
          .font(.system(size: 11))
          .foregroundStyle(Theme.muted)
      }

      Spacer()

      VStack(alignment: .trailing, spacing: 3) {
        Text("\(record.direction == .incoming ? "+" : "-")\(record.amount) \(symbol)")
          .font(.system(size: 14, weight: .semibold))
          .foregroundStyle(record.direction == .incoming ? Theme.success : Theme.text)
        if let fee = record.fee, !fee.isEmpty, record.direction == .outgoing {
          Text("fee \(fee)")
            .font(.system(size: 11))
            .foregroundStyle(Theme.muted)
        }
      }
    }
    .padding(.vertical, 6)
  }
}

struct ScreenHeader: View {
  var title: String
  var subtitle: String?
  var onBack: (() -> Void)?

  var body: some View {
    HStack(alignment: .center, spacing: 12) {
      if let onBack {
        Button(action: onBack) {
          Image(systemName: "chevron.left")
            .font(.system(size: 16, weight: .semibold))
            .foregroundStyle(Theme.text)
            .frame(width: 34, height: 34)
            .background(Theme.surface)
            .clipShape(Circle())
        }
      }
      VStack(alignment: .leading, spacing: 2) {
        Text(title)
          .font(.system(size: 22, weight: .bold))
          .foregroundStyle(Theme.text)
        if let subtitle {
          Text(subtitle)
            .font(.system(size: 12))
            .foregroundStyle(Theme.muted)
        }
      }
      Spacer()
    }
  }
}