using Azure.Data.Tables;
using Microsoft.Extensions.Options;
using Tango.Portal.Chat.Web.Models;

namespace Tango.Portal.Chat.Web.Services
{
    public sealed class AIInstructionService
    {
        private readonly TableClient _tableClient;
        private readonly ILogger<AIInstructionService> _logger;

        public AIInstructionService(IOptions<AzureStorageOptions> options, ILogger<AIInstructionService> logger)
        {
            _logger = logger;
            var serviceClient = new TableServiceClient(options.Value.ConnectionString);
            _tableClient = serviceClient.GetTableClient("AIInstructions");
            
            // Create table if it doesn't exist
            _tableClient.CreateIfNotExists();
        }

        public async Task<bool> AddInstructionAsync(string instruction, string createdBy)
        {
            try
            {
                var aiInstruction = new AIInstruction
                {
                    RowKey = Guid.NewGuid().ToString(),
                    Instruction = instruction,
                    CreatedAt = DateTime.UtcNow,
                    CreatedBy = createdBy
                };

                await _tableClient.AddEntityAsync(aiInstruction);
                _logger.LogInformation("Added AI instruction by {CreatedBy}: {Instruction}", createdBy, instruction);
                return true;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to add AI instruction: {Instruction}", instruction);
                return false;
            }
        }

        public async Task<bool> DeleteLastInstructionAsync()
        {
            try
            {
                var instructions = await GetAllInstructionsAsync();
                var lastInstruction = instructions.OrderByDescending(i => i.CreatedAt).FirstOrDefault();
                
                if (lastInstruction == null)
                {
                    _logger.LogWarning("No instructions found to delete");
                    return false;
                }

                await _tableClient.DeleteEntityAsync(lastInstruction.PartitionKey, lastInstruction.RowKey);
                _logger.LogInformation("Deleted last AI instruction: {Instruction}", lastInstruction.Instruction);
                return true;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to delete last AI instruction");
                return false;
            }
        }

        public async Task<List<AIInstruction>> GetAllInstructionsAsync()
        {
            try
            {
                var instructions = new List<AIInstruction>();
                await foreach (var instruction in _tableClient.QueryAsync<AIInstruction>())
                {
                    instructions.Add(instruction);
                }
                return instructions.OrderBy(i => i.CreatedAt).ToList();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to retrieve AI instructions");
                return new List<AIInstruction>();
            }
        }

        public async Task<string> GetInstructionsTextAsync()
        {
            var instructions = await GetAllInstructionsAsync();
            if (!instructions.Any())
                return string.Empty;

            var instructionTexts = instructions.Select(i => i.Instruction);
            return string.Join("\n", instructionTexts);
        }
    }
}