using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using JobTrackerApi.Data;
using JobTrackerApi.Models;

namespace JobTrackerApi.Controllers
{
    [ApiController]
    [Route("api/correspondence")]
    public class CorrespondenceController : ControllerBase
    {
        private readonly JobTrackerContext _db;

        public CorrespondenceController(JobTrackerContext db)
        {
            _db = db;
        }

        // GET all messages for a job
        [HttpGet("{jobId:int}")]
        public async Task<ActionResult<List<Correspondence>>> GetForJob([FromRoute] int jobId, CancellationToken cancellationToken)
        {
            var jobOk = await _db.JobApplications.AnyAsync(j => j.Id == jobId, cancellationToken);
            if (!jobOk) return NotFound();

            var messages = await _db.Correspondences
                .Where(c => c.JobApplicationId == jobId)
                .OrderBy(c => c.Date)
                .ToListAsync(cancellationToken);

            return Ok(messages);
        }

        public sealed record CreateCorrespondenceRequest(int JobApplicationId, string From, string Content);
        public sealed record CreateCorrespondenceRequestV2(
            int JobApplicationId,
            string From,
            string Content,
            string? Subject,
            string? Channel,
            DateTime? Date
        );

        // POST new message
        [HttpPost]
        public async Task<ActionResult<Correspondence>> Create([FromBody] CreateCorrespondenceRequestV2 request, CancellationToken cancellationToken)
        {
            if (request.JobApplicationId <= 0) return BadRequest("Valid jobApplicationId is required.");
            if (string.IsNullOrWhiteSpace(request.From)) return BadRequest("From is required.");
            if (string.IsNullOrWhiteSpace(request.Content)) return BadRequest("Content is required.");

            var exists = await _db.JobApplications.AnyAsync(j => j.Id == request.JobApplicationId, cancellationToken);
            if (!exists) return BadRequest("jobApplicationId does not exist.");

            var message = new Correspondence
            {
                JobApplicationId = request.JobApplicationId,
                From = request.From.Trim(),
                Subject = string.IsNullOrWhiteSpace(request.Subject) ? null : request.Subject.Trim(),
                Channel = string.IsNullOrWhiteSpace(request.Channel) ? null : request.Channel.Trim(),
                Content = request.Content,
                Date = request.Date ?? DateTime.Now,
            };

            _db.Correspondences.Add(message);
            await _db.SaveChangesAsync(cancellationToken);

            return CreatedAtAction(nameof(GetForJob), new { jobId = message.JobApplicationId }, message);
        }


        [HttpDelete("{id:int}")]
        public async Task<IActionResult> Delete([FromRoute] int id, CancellationToken cancellationToken)
        {
            var message = await _db.Correspondences.FirstOrDefaultAsync(c => c.Id == id, cancellationToken);
            if (message is null) return NotFound();

            _db.Correspondences.Remove(message);
            await _db.SaveChangesAsync(cancellationToken);
            return NoContent();
        }
    }
}