import SwiftUI

struct TransferReceiptView: View {
    let receipt: TransferReceiptData
    var onSaveContact: ((BankContact) -> Void)? = nil
    var onDone: () -> Void

    @State private var contactSaved = false

    private let primary = Color(red: 0.247, green: 0.396, blue: 0.678)

    var body: some View {
        NavigationStack {
            ScrollView {
                VStack(spacing: 0) {
                    successHeader
                    detailsCard
                    Spacer(minLength: 32)
                    doneButton
                }
                .padding(.horizontal, 16)
                .padding(.bottom, 32)
            }
            .background(Color(.systemGroupedBackground))
            .navigationTitle("Receipt")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Done") { onDone() }
                        .foregroundStyle(primary)
                }
            }
        }
    }

    // MARK: - Sub-views

    private var successHeader: some View {
        VStack(spacing: 12) {
            ZStack {
                Circle()
                    .fill(Color.green.opacity(0.15))
                    .frame(width: 80, height: 80)
                Image(systemName: "checkmark.circle.fill")
                    .font(.system(size: 44))
                    .foregroundStyle(.green)
            }
            .padding(.top, 32)

            Text("Transfer Successful")
                .font(.title2.bold())

            Text(amountText)
                .font(.system(size: 36, weight: .bold, design: .rounded))
                .foregroundStyle(primary)
        }
        .frame(maxWidth: .infinity)
        .padding(.bottom, 24)
    }

    private var detailsCard: some View {
        VStack(spacing: 0) {
            row(label: "From", value: receipt.fromAccountNumber)
            Divider().padding(.leading, 16)
            row(label: "Bank", value: receipt.fromBankName)
            Divider().padding(.leading, 16)
            row(label: "To Account", value: receipt.toAccountNumber)
            Divider().padding(.leading, 16)
            row(label: "Beneficiary", value: receipt.toAccountName.isEmpty ? "—" : receipt.toAccountName)
            if !receipt.reference.isEmpty {
                Divider().padding(.leading, 16)
                row(label: "Reference", value: receipt.reference)
            }
            if !receipt.date.isEmpty {
                Divider().padding(.leading, 16)
                row(label: "Date", value: receipt.date)
            }
            if !receipt.message.isEmpty && receipt.message != "Transfer successful" {
                Divider().padding(.leading, 16)
                row(label: "Note", value: receipt.message)
            }
        }
        .background(Color(.secondarySystemGroupedBackground))
        .clipShape(RoundedRectangle(cornerRadius: 12))
    }

    private var doneButton: some View {
        VStack(spacing: 12) {
            if let onSave = onSaveContact {
                Button {
                    onSave(makeContact())
                    contactSaved = true
                } label: {
                    Label(contactSaved ? "Contact Saved" : "Save Contact",
                          systemImage: contactSaved ? "checkmark.circle.fill" : "person.badge.plus")
                        .font(.headline)
                        .frame(maxWidth: .infinity)
                        .padding(.vertical, 14)
                        .background(contactSaved ? Color.green.opacity(0.15) : Color(.secondarySystemGroupedBackground))
                        .foregroundStyle(contactSaved ? .green : primary)
                        .clipShape(RoundedRectangle(cornerRadius: 12))
                }
                .disabled(contactSaved)
            }
            Button(action: onDone) {
                Text("Done")
                    .font(.headline)
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, 14)
                    .background(primary)
                    .foregroundStyle(.white)
                    .clipShape(RoundedRectangle(cornerRadius: 12))
            }
        }
    }

    private func makeContact() -> BankContact {
        let source = receipt.fromBankName.lowercased().contains("islamic") ? "MIB" : "BML"
        let displayName = receipt.toAccountName.isEmpty ? receipt.toAccountNumber : receipt.toAccountName
        return BankContact(
            id:              "LOCAL_\(source)_\(receipt.toAccountNumber)",
            benefNo:         receipt.toAccountNumber,
            benefName:       displayName,
            benefNickName:   nil,
            benefAccount:    receipt.toAccountNumber,
            benefType:       source,
            bankColor:       nil,
            benefBankName:   nil,
            bankCode:        nil,
            benefStatus:     "Active",
            transferCyDesc:  receipt.currency,
            customerImgHash: nil,
            benefCategoryId: nil,
            profileId:       nil,
            source:          source
        )
    }

    private func row(label: String, value: String) -> some View {
        HStack {
            Text(label)
                .font(.subheadline)
                .foregroundStyle(.secondary)
                .frame(width: 110, alignment: .leading)
            Text(value)
                .font(.subheadline)
                .multilineTextAlignment(.trailing)
                .frame(maxWidth: .infinity, alignment: .trailing)
        }
        .padding(.horizontal, 16)
        .padding(.vertical, 12)
    }

    private var amountText: String {
        let f = NumberFormatter()
        f.numberStyle = .decimal
        f.minimumFractionDigits = 2
        f.maximumFractionDigits = 2
        f.usesGroupingSeparator = true
        return "\(receipt.currency) \(f.string(from: NSNumber(value: receipt.amount)) ?? "0.00")"
    }
}

#Preview {
    TransferReceiptView(receipt: TransferReceiptData(
        fromAccountNumber: "7701234567890",
        fromBankName:      "Bank of Maldives",
        toAccountNumber:   "7709876543210",
        toAccountName:     "Ahmed Mohamed",
        amount:            1500.00,
        currency:          "MVR",
        reference:         "TXN20260607001",
        date:              "2026-06-07 14:32:00",
        message:           "Transfer successful"
    )) {}
}