using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using PayRollBLL.SAP.Config;
using System;
using System.Linq;
using System.Text;
using System.Text.Json;

namespace PayRollBLL.SAP.Audit
{
    /// <summary>
    /// Writes one log file per day to the configured AuditLogDirectory.
    ///
    /// File naming:  SAP_Declaration_2026-05-22.log
    /// Each file contains REQUEST blocks (payload + parameters) and
    /// RESPONSE blocks (HTTP status + SAP message + raw body), timestamped to the millisecond.
    /// </summary>
    public class SapDeclarationAuditLog : ISapDeclarationAuditLog
    {
        private readonly ILogger<SapDeclarationAuditLog> _logger;

        public SapDeclarationAuditLog(
            IOptions<SapItDeclarationOptions>   options,
            ILogger<SapDeclarationAuditLog>     logger)
        {
            _logger = logger;
        }

        // ── Public API ────────────────────────────────────────────────────────────────

        public void LogRequest(
            int    infotype,
            int    declarationId,
            int    employeeId,
            int    periodId,
            string endpointPath,
            string description,
            string jsonPayload)
        {
            var sb = new StringBuilder();
            string ts    = Ts();
            string label = Label(infotype, description, endpointPath);

            sb.AppendLine();
            sb.AppendLine($"â–¶ REQUEST   {ts}   Infotype {infotype}");
            sb.AppendLine(ThinBar());
            sb.AppendLine($"  Infotype      : {infotype}  ({description})");
            sb.AppendLine($"  Endpoint      : {endpointPath}");
            sb.AppendLine($"  DeclarationId : {declarationId}");
            sb.AppendLine($"  EmployeeId    : {employeeId}");
            sb.AppendLine($"  PeriodId      : {periodId}");
            sb.AppendLine(ThinBar());
            sb.AppendLine("  PAYLOAD:");
            sb.AppendLine(Indent(TryPrettyPrint(jsonPayload)));
            sb.AppendLine(ThickBar());

            Write(sb.ToString());
        }

        public void LogResponse(
            int    infotype,
            string endpointPath,
            string description,
            int    httpStatus,
            bool   isSuccess,
            string message,
            string responseBody)
        {
            var sb = new StringBuilder();
            string ts     = Ts();
            string status = isSuccess ? "SUCCESS ✔" : "FAILED  ✘";

            sb.AppendLine();
            sb.AppendLine($"â—€ RESPONSE  {ts}   Infotype {infotype}   HTTP {httpStatus}   {status}");
            sb.AppendLine(ThinBar());
            sb.AppendLine($"  Infotype  : {infotype}  ({description})");
            sb.AppendLine($"  Endpoint  : {endpointPath}");
            sb.AppendLine($"  Message   : {message}");
            sb.AppendLine(ThinBar());
            sb.AppendLine("  SAP RESPONSE BODY:");
            sb.AppendLine(Indent(TryPrettyPrint(responseBody)));
            sb.AppendLine(ThickBar());

            Write(sb.ToString());
        }

        // ── Internal helpers ──────────────────────────────────────────────────────────

        private void Write(string content)
        {
            // Route through ILogger so the audit entry is captured by the configured sink
            // (Serilog file/stdout/aggregator) rather than a pod-local file.
            _logger.LogInformation("SAP Declaration Audit: {AuditEntry}", content);
        }

        private static string TryPrettyPrint(string json)
        {
            if (string.IsNullOrWhiteSpace(json)) return "(empty)";
            try
            {
                using var doc = JsonDocument.Parse(json);
                return JsonSerializer.Serialize(
                    doc.RootElement,
                    new JsonSerializerOptions { WriteIndented = true });
            }
            catch
            {
                return json;
            }
        }

        private static string Indent(string text)
        {
            if (string.IsNullOrWhiteSpace(text)) return "  (empty)";
            return string.Join(
                Environment.NewLine,
                text.Split(new[] { "\r\n", "\n" }, StringSplitOptions.None)
                    .Select(line => "  " + line));
        }

        private static string Label(int infotype, string description, string endpointPath) =>
            string.IsNullOrWhiteSpace(description)
                ? $"IT{infotype}  |  {endpointPath}"
                : $"IT{infotype} {description}  |  {endpointPath}";

        private static string Ts()       => DateTime.UtcNow.ToString("dd-MMM-yyyy  HH:mm:ss.fff");
        private static string ThinBar()  => new('─', 84);
        private static string ThickBar() => new('═', 84);
    }
}