using Microsoft.AspNetCore.Mvc;
using WIDESEAWCS_S7Simulator.Core.Entities;
using WIDESEAWCS_S7Simulator.Core.Interfaces;

namespace WIDESEAWCS_S7Simulator.Server.Controllers
{
    /// <summary>
    /// 仿真器实例管理控制器
    /// </summary>
    [ApiController]
    [Route("api/[controller]")]
    public class SimulatorInstancesController : ControllerBase
    {
        private readonly ISimulatorInstanceManager _instanceManager;
        private readonly ILogger<SimulatorInstancesController> _logger;

        public SimulatorInstancesController(
            ISimulatorInstanceManager instanceManager,
            ILogger<SimulatorInstancesController> logger)
        {
            _instanceManager = instanceManager ?? throw new ArgumentNullException(nameof(instanceManager));
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
        }

        /// <summary>
        /// 获取所有实例列表
        /// </summary>
        [HttpGet]
        [ProducesResponseType(typeof(IEnumerable<InstanceState>), StatusCodes.Status200OK)]
        public ActionResult<IEnumerable<InstanceState>> GetAllInstances()
        {
            try
            {
                var instances = _instanceManager.GetAllInstances();
                var states = instances.Select(i => i.GetState()).ToList();
                return Ok(states);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to get all instances");
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to retrieve instances" });
            }
        }

        /// <summary>
        /// 创建新实例
        /// </summary>
        [HttpPost]
        [ProducesResponseType(typeof(InstanceState), StatusCodes.Status201Created)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        public async Task<ActionResult<InstanceState>> CreateInstance([FromBody] InstanceConfig config)
        {
            try
            {
                if (config == null)
                {
                    return BadRequest(new { error = "Instance configuration is required" });
                }

                if (string.IsNullOrWhiteSpace(config.Id))
                {
                    return BadRequest(new { error = "Instance ID is required" });
                }

                if (string.IsNullOrWhiteSpace(config.Name))
                {
                    return BadRequest(new { error = "Instance name is required" });
                }

                if (_instanceManager.InstanceExists(config.Id))
                {
                    return Conflict(new { error = $"Instance with ID '{config.Id}' already exists" });
                }

                if (config.Port <= 0 || config.Port > 65535)
                {
                    return BadRequest(new { error = "Port must be between 1 and 65535" });
                }

                var instance = await _instanceManager.CreateInstanceAsync(config);
                var state = instance.GetState();

                return CreatedAtAction(
                    nameof(GetInstance),
                    new { id = config.Id },
                    state);
            }
            catch (ArgumentException ex)
            {
                _logger.LogWarning(ex, "Invalid instance configuration");
                return BadRequest(new { error = ex.Message });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to create instance");
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to create instance" });
            }
        }

        /// <summary>
        /// 获取指定实例详情
        /// </summary>
        [HttpGet("{id}")]
        [ProducesResponseType(typeof(InstanceState), StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public ActionResult<InstanceState> GetInstance(string id)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(id))
                {
                    return BadRequest(new { error = "Instance ID is required" });
                }

                var instance = _instanceManager.GetInstance(id);
                if (instance == null)
                {
                    return NotFound(new { error = $"Instance with ID '{id}' not found" });
                }

                var state = instance.GetState();
                return Ok(state);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to get instance {InstanceId}", id);
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to retrieve instance" });
            }
        }

        /// <summary>
        /// 更新实例配置
        /// </summary>
        [HttpPut("{id}")]
        [ProducesResponseType(typeof(InstanceState), StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<ActionResult<InstanceState>> UpdateInstance(string id, [FromBody] InstanceConfig config)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(id))
                {
                    return BadRequest(new { error = "Instance ID is required" });
                }

                if (config == null)
                {
                    return BadRequest(new { error = "Instance configuration is required" });
                }

                var instance = _instanceManager.GetInstance(id);
                if (instance == null)
                {
                    return NotFound(new { error = $"Instance with ID '{id}' not found" });
                }

                // Validate port if changed
                if (config.Port <= 0 || config.Port > 65535)
                {
                    return BadRequest(new { error = "Port must be between 1 and 65535" });
                }

                // Delete existing instance and recreate with new config
                // Note: This is a simplified approach. In production, you might want to support hot-reload
                bool wasRunning = instance.GetState().Status == Core.Enums.InstanceStatus.Running;
                await _instanceManager.DeleteInstanceAsync(id, deleteConfig: false);

                config.Id = id; // Ensure ID matches route parameter
                var newInstance = await _instanceManager.CreateInstanceAsync(config);

                if (wasRunning)
                {
                    await _instanceManager.StartInstanceAsync(id);
                }

                var state = newInstance.GetState();
                return Ok(state);
            }
            catch (ArgumentException ex)
            {
                _logger.LogWarning(ex, "Invalid instance configuration");
                return BadRequest(new { error = ex.Message });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to update instance {InstanceId}", id);
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to update instance" });
            }
        }

        /// <summary>
        /// 删除实例
        /// </summary>
        [HttpDelete("{id}")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> DeleteInstance(string id, [FromQuery] bool deleteConfig = true)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(id))
                {
                    return BadRequest(new { error = "Instance ID is required" });
                }

                if (!_instanceManager.InstanceExists(id))
                {
                    return NotFound(new { error = $"Instance with ID '{id}' not found" });
                }

                await _instanceManager.DeleteInstanceAsync(id, deleteConfig);
                return NoContent();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to delete instance {InstanceId}", id);
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to delete instance" });
            }
        }

        /// <summary>
        /// 启动实例
        /// </summary>
        [HttpPost("{id}/start")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        public async Task<ActionResult<InstanceState>> StartInstance(string id)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(id))
                {
                    return BadRequest(new { error = "Instance ID is required" });
                }

                if (!_instanceManager.InstanceExists(id))
                {
                    return NotFound(new { error = $"Instance with ID '{id}' not found" });
                }

                bool success = await _instanceManager.StartInstanceAsync(id);
                if (!success)
                {
                    return BadRequest(new { error = "Failed to start instance" });
                }

                var instance = _instanceManager.GetInstance(id);
                var state = instance?.GetState();
                return Ok(state);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to start instance {InstanceId}", id);
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to start instance" });
            }
        }

        /// <summary>
        /// 停止实例
        /// </summary>
        [HttpPost("{id}/stop")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<ActionResult<InstanceState>> StopInstance(string id)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(id))
                {
                    return BadRequest(new { error = "Instance ID is required" });
                }

                if (!_instanceManager.InstanceExists(id))
                {
                    return NotFound(new { error = $"Instance with ID '{id}' not found" });
                }

                await _instanceManager.StopInstanceAsync(id);

                var instance = _instanceManager.GetInstance(id);
                var state = instance?.GetState();
                return Ok(state);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to stop instance {InstanceId}", id);
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to stop instance" });
            }
        }

        /// <summary>
        /// 重启实例
        /// </summary>
        [HttpPost("{id}/restart")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        public async Task<ActionResult<InstanceState>> RestartInstance(string id)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(id))
                {
                    return BadRequest(new { error = "Instance ID is required" });
                }

                if (!_instanceManager.InstanceExists(id))
                {
                    return NotFound(new { error = $"Instance with ID '{id}' not found" });
                }

                bool success = await _instanceManager.RestartInstanceAsync(id);
                if (!success)
                {
                    return BadRequest(new { error = "Failed to restart instance" });
                }

                var instance = _instanceManager.GetInstance(id);
                var state = instance?.GetState();
                return Ok(state);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to restart instance {InstanceId}", id);
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to restart instance" });
            }
        }

        /// <summary>
        /// 启动所有自动启动实例
        /// </summary>
        [HttpPost("start-all")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public async Task<ActionResult> StartAllAutoStartInstances()
        {
            try
            {
                await _instanceManager.LoadSavedInstancesAsync(autoStart: true);
                return Ok(new {
                    message = "Started all auto-start instances",
                    runningCount = _instanceManager.GetRunningInstanceCount()
                });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to start all instances");
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to start instances" });
            }
        }

        /// <summary>
        /// 停止所有实例
        /// </summary>
        [HttpPost("stop-all")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public async Task<ActionResult> StopAllInstances()
        {
            try
            {
                await _instanceManager.StopAllInstancesAsync();
                return Ok(new {
                    message = "Stopped all instances",
                    runningCount = _instanceManager.GetRunningInstanceCount()
                });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to stop all instances");
                return StatusCode(StatusCodes.Status500InternalServerError, new { error = "Failed to stop instances" });
            }
        }
    }
}