using System.Text;
using Core.Entities;
using Core.Models;
using Core.Parsers;

namespace Core.Services;

/// <summary>
/// Service implementation for parsing event occurrence text data.
/// Wraps EventOccurrenceParser to support text input and error collection.
/// </summary>
public class EventOccurrenceParserService : IEventOccurrenceParserService
{
    /// <inheritdoc/>
    public EventOccurrenceParseResult ParseFromText(string text, ICollection<EventDefinition> events)
    {
        var result = new EventOccurrenceParseResult();

        if (string.IsNullOrWhiteSpace(text))
        {
            result.Errors.Add("Input text is empty or whitespace.");
            return result;
        }

        try
        {
            // Create a temporary file from the text content
            var tempFile = Path.GetTempFileName();
            try
            {
                File.WriteAllText(tempFile, text, Encoding.UTF8);
                var fileInfo = new FileInfo(tempFile);

                // Use the existing EventOccurrenceParser
                var parser = new EventOccurrenceParser(fileInfo, events);
                var parsedOccurrences = parser.Parse();

                // Convert parsed occurrences to result format, handling special event types
                foreach (var kvp in parsedOccurrences)
                {
                    var eventDefinition = kvp.Key;
                    var occurrences = kvp.Value;

                    // Check if this is a special event type (GeneralSchedule or VotingDelegates)
                    if (eventDefinition == EventDefinition.GeneralSchedule || 
                        eventDefinition == EventDefinition.VotingDelegates)
                    {
                        // For special events, set EventDefinitionId to null and set SpecialEventType
                        foreach (var occurrence in occurrences)
                        {
                            occurrence.EventDefinitionId = null;
                            occurrence.SpecialEventType = eventDefinition == EventDefinition.GeneralSchedule 
                                ? "GeneralSchedule" 
                                : "VotingDelegates";
                        }

                        // Add to result with the special EventDefinition as key
                        result.Occurrences[eventDefinition] = occurrences;
                    }
                    else
                    {
                        // For regular events, set EventDefinitionId and ensure SpecialEventType is null
                        foreach (var occurrence in occurrences)
                        {
                            occurrence.EventDefinitionId = eventDefinition.Id;
                            occurrence.SpecialEventType = null;
                        }

                        result.Occurrences[eventDefinition] = occurrences;
                    }
                }

                // Track any occurrences without a matching EventDefinition
                // (This would be detected if parser.Parse() returns occurrences with null EventDefinition keys,
                // but the current parser implementation doesn't do this - all occurrences have a currentEventDefinition)
            }
            finally
            {
                // Clean up temporary file
                try
                {
                    if (File.Exists(tempFile))
                    {
                        File.Delete(tempFile);
                    }
                }
                catch
                {
                    // Ignore cleanup errors
                }
            }
        }
        catch (Exception ex)
        {
            result.Errors.Add($"Error parsing text: {ex.Message}");
            if (ex.InnerException != null)
            {
                result.Errors.Add($"Inner exception: {ex.InnerException.Message}");
            }
        }

        return result;
    }
}