using System;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text.Json;
using System.Threading.Tasks;

namespace Gott.Services
{
    public class StripeCheckResult
    {
        public string Status { get; set; }     // "ok", "invalid", "error"
        public string Message { get; set; }
        public bool IsLiveKey { get; set; }
        public string Currency { get; set; }
        public long? BalanceAvailable { get; set; }
        public long? BalancePending { get; set; }
        public string AccountId { get; set; }
        public string AccountName { get; set; }
        public string AccountEmail { get; set; }
        public string AccountCountry { get; set; }
        public bool? PayoutsEnabled { get; set; }
        public bool? ChargesEnabled { get; set; }
    }

    public static class StripeKeyChecker
    {
        public static async Task<StripeCheckResult> CheckKeyAsync(IHttpClientFactory httpFactory, string apiKey)
        {
            try
            {
                var client = httpFactory.CreateClient();
                client.Timeout = TimeSpan.FromSeconds(30);

                var isLive = apiKey.StartsWith("sk_live_", StringComparison.Ordinal);

                // Step 1: Check /v1/balance (read-only, no cost)
                var balanceRequest = new HttpRequestMessage(HttpMethod.Get, "https://api.stripe.com/v1/balance");
                balanceRequest.Headers.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);

                var balanceResp = await client.SendAsync(balanceRequest);
                var balanceBody = await balanceResp.Content.ReadAsStringAsync();
                var balanceCode = (int)balanceResp.StatusCode;

                if (balanceCode == 401)
                {
                    return new StripeCheckResult
                    {
                        Status = "invalid",
                        Message = "Ungültig oder revoked (401)",
                        IsLiveKey = isLive
                    };
                }

                if (balanceCode >= 400)
                {
                    // Parse error
                    var errorMsg = "Unbekannter Fehler";
                    try
                    {
                        using var errDoc = JsonDocument.Parse(balanceBody);
                        if (errDoc.RootElement.TryGetProperty("error", out var errObj) &&
                            errObj.TryGetProperty("message", out var msg))
                            errorMsg = msg.GetString();
                    }
                    catch { }

                    return new StripeCheckResult
                    {
                        Status = "error",
                        Message = $"API-Fehler ({balanceCode}): {errorMsg}",
                        IsLiveKey = isLive
                    };
                }

                // Parse balance
                string currency = null;
                long balanceAvailable = 0;
                long balancePending = 0;

                try
                {
                    using var balDoc = JsonDocument.Parse(balanceBody);
                    var root = balDoc.RootElement;

                    if (root.TryGetProperty("available", out var available) && available.GetArrayLength() > 0)
                    {
                        var first = available[0];
                        if (first.TryGetProperty("currency", out var cur))
                            currency = cur.GetString()?.ToUpperInvariant();
                        if (first.TryGetProperty("amount", out var amt))
                            balanceAvailable = amt.GetInt64();
                    }

                    if (root.TryGetProperty("pending", out var pending) && pending.GetArrayLength() > 0)
                    {
                        var first = pending[0];
                        if (first.TryGetProperty("amount", out var amt))
                            balancePending = amt.GetInt64();
                    }
                }
                catch { }

                // Step 2: Get account info via /v1/account
                string accountId = null;
                string accountName = null;
                string accountEmail = null;
                string accountCountry = null;
                bool? payoutsEnabled = null;
                bool? chargesEnabled = null;

                try
                {
                    var accountRequest = new HttpRequestMessage(HttpMethod.Get, "https://api.stripe.com/v1/account");
                    accountRequest.Headers.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);

                    var accountResp = await client.SendAsync(accountRequest);
                    if ((int)accountResp.StatusCode == 200)
                    {
                        var accountBody = await accountResp.Content.ReadAsStringAsync();
                        using var accDoc = JsonDocument.Parse(accountBody);
                        var acc = accDoc.RootElement;

                        if (acc.TryGetProperty("id", out var id))
                            accountId = id.GetString();
                        if (acc.TryGetProperty("business_profile", out var bp) && bp.TryGetProperty("name", out var name))
                            accountName = name.GetString();
                        if (acc.TryGetProperty("email", out var email))
                            accountEmail = email.GetString();
                        if (acc.TryGetProperty("country", out var country))
                            accountCountry = country.GetString();
                        if (acc.TryGetProperty("payouts_enabled", out var pe))
                            payoutsEnabled = pe.GetBoolean();
                        if (acc.TryGetProperty("charges_enabled", out var ce))
                            chargesEnabled = ce.GetBoolean();
                    }
                }
                catch { }

                // Build message
                var parts = new System.Collections.Generic.List<string>();

                parts.Add(isLive ? "🔴 LIVE Key" : "🟡 Test Key");

                if (accountName != null)
                    parts.Add($"Account: {accountName}");
                else if (accountId != null)
                    parts.Add($"Account: {accountId}");

                if (accountEmail != null)
                    parts.Add($"Email: {accountEmail}");

                if (accountCountry != null)
                    parts.Add($"Land: {accountCountry}");

                if (currency != null)
                {
                    var availFormatted = FormatAmount(balanceAvailable, currency);
                    var pendingFormatted = FormatAmount(balancePending, currency);
                    parts.Add($"Balance: {availFormatted} verfügbar, {pendingFormatted} ausstehend");
                }

                if (chargesEnabled.HasValue)
                    parts.Add(chargesEnabled.Value ? "✅ Charges aktiv" : "❌ Charges deaktiviert");

                if (payoutsEnabled.HasValue)
                    parts.Add(payoutsEnabled.Value ? "✅ Payouts aktiv" : "❌ Payouts deaktiviert");

                return new StripeCheckResult
                {
                    Status = "ok",
                    Message = string.Join(" · ", parts),
                    IsLiveKey = isLive,
                    Currency = currency,
                    BalanceAvailable = balanceAvailable,
                    BalancePending = balancePending,
                    AccountId = accountId,
                    AccountName = accountName,
                    AccountEmail = accountEmail,
                    AccountCountry = accountCountry,
                    PayoutsEnabled = payoutsEnabled,
                    ChargesEnabled = chargesEnabled
                };
            }
            catch (Exception ex)
            {
                return new StripeCheckResult
                {
                    Status = "error",
                    Message = ex.Message,
                    IsLiveKey = apiKey.StartsWith("sk_live_", StringComparison.Ordinal)
                };
            }
        }

        private static string FormatAmount(long amountInCents, string currency)
        {
            var amount = amountInCents / 100.0;
            return $"{amount:N2} {currency}";
        }
    }
}