using Backend.DatabaseHandler;
using Backend.Interface;
using Backend.ServiceHandler;
using Microsoft.AspNetCore.Mvc;

namespace Backend.Controllers
{
	[ApiController]
	[Route("api/news-sentiment")]
	public sealed class NewsSentimentController : ControllerBase
	{
		private static DateTime _lastRefresh = DateTime.MinValue;
		private static readonly Lock _refreshLock = new();
		private readonly NewsSentimentService _service;
		private readonly IUserInterestStore _interests;
		private readonly INewsSentimentStore _store;

		public NewsSentimentController(
			NewsSentimentService service,
			IUserInterestStore interests,
			INewsSentimentStore store)
		{
			_service = service;
			_interests = interests;
			_store = store;
		}

		[HttpGet]
		public async Task<IActionResult> Analyze(
			[FromQuery] string keyword,
			CancellationToken cancellationToken)
		{
			var results = await _service.AnalyzeAsync(keyword, cancellationToken);
			return Ok(results);
		}

		[HttpGet("feed")]
		public async Task<IActionResult> Feed(
			[FromQuery] string user,
			[FromQuery] string? keyword = null,
			[FromQuery(Name = "request-amount")] int requestAmount = 20,
			CancellationToken cancellationToken = default)
		{
			if (string.IsNullOrWhiteSpace(user))
				return BadRequest("User cannot be empty.");

			if (requestAmount < 1)
				requestAmount = 1;

			List<string> keywords;

			if (!string.IsNullOrWhiteSpace(keyword))
			{
				keywords = [keyword.Trim()];
			}
			else
			{
				var symbols = await _interests.FetchAllAsync(user, "symbol");
				var topics = await _interests.FetchAllAsync(user, "topic");
				keywords = symbols.Concat(topics).Distinct().ToList();
			}

			if (keywords.Count == 0)
				return Ok(Array.Empty<object>());

			var results = await _store.GetFeedAsync(keywords, requestAmount, cancellationToken);

			return Ok(results.Select(NewsFeedItem.From));
		}

		[HttpGet("refresh")]
		public async Task<ActionResult<BoolResponse>> Refresh(
			[FromQuery] string user,
			CancellationToken cancellationToken = default)
		{
			try
			{
				if (string.IsNullOrWhiteSpace(user))
					return BadRequest("User cannot be empty.");

				lock (_refreshLock)
				{
					if ((DateTime.UtcNow - _lastRefresh).TotalSeconds < 5)
						return Ok(new BoolResponse { Success = false });
					_lastRefresh = DateTime.UtcNow;
				}

				var symbols = await _interests.FetchAllAsync(user, "symbol");
				var topics = await _interests.FetchAllAsync(user, "topic");
				var kws = symbols.Concat(topics).Distinct().ToList();

				foreach (var kw in kws)
				{
					await _service.AnalyzeAsync(kw, cancellationToken);
				}

				return Ok(new BoolResponse { Success = true });
			}
			catch (Exception)
			{
				return Ok(new BoolResponse { Success = false });
			}
		}
	}
}