using ControlCenter.Data;
using ControlCenter.Models;
using Microsoft.EntityFrameworkCore;

namespace ControlCenter.Repositories;

/// <summary>
/// EF Core implementation of <see cref="IAgentStateRepository"/>.
///
/// <para>Queries the <c>agents</c> table via <see cref="ControlCenterDbContext"/>
/// using snake_case column mappings defined in the <see cref="Data.Configurations.AgentStateConfiguration"/>.
/// All write operations call <c>SaveChangesAsync</c> immediately.</para>
/// </summary>
public class AgentStateRepository : IAgentStateRepository
{
    private readonly ControlCenterDbContext _context;
    private readonly ILogger<AgentStateRepository> _logger;

    public AgentStateRepository(
        ControlCenterDbContext context,
        ILogger<AgentStateRepository> logger)
    {
        _context = context;
        _logger = logger;
    }

    /// <inheritdoc />
    public async Task<IEnumerable<AgentState>> GetAllAsync()
    {
        _logger.LogDebug("Fetching all agent states");
        return await _context.AgentStates.ToListAsync();
    }

    /// <inheritdoc />
    public async Task<AgentState?> GetBySessionKeyAsync(string sessionKey)
    {
        _logger.LogDebug("Looking up agent state by session key: {SessionKey}", sessionKey);
        return await _context.AgentStates
            .FirstOrDefaultAsync(a => a.SessionKey == sessionKey);
    }

    /// <inheritdoc />
    public async Task<AgentState?> UpdateStatusAsync(Guid id, string status)
    {
        _logger.LogDebug("Updating agent status: {Id} → {Status}", id, status);

        var entity = await _context.AgentStates.FindAsync(id);
        if (entity is null)
        {
            _logger.LogWarning("Agent state not found: {Id}", id);
            return null;
        }

        entity.Status = status;
        entity.LastActivity = DateTime.UtcNow;

        _context.AgentStates.Update(entity);
        await _context.SaveChangesAsync();

        return entity;
    }
}