using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Purrse.Core.DTOs;
using Purrse.Core.Enums;
using Purrse.Core.Models;
using Purrse.Data;
using System.Security.Claims;

namespace Purrse.Api.Controllers;

[Authorize]
[ApiController]
[Route("api/[controller]")]
public class ReconciliationController : ControllerBase
{
    private readonly PurrseDbContext _db;
    private Guid UserId => Guid.Parse(User.FindFirstValue(ClaimTypes.NameIdentifier)!);

    public ReconciliationController(PurrseDbContext db) => _db = db;

    [HttpPost("{accountId}/start")]
    public async Task<ActionResult<ReconciliationResponse>> Start(Guid accountId, StartReconciliationRequest request)
    {
        var account = await _db.Accounts.FirstOrDefaultAsync(a => a.Id == accountId && a.UserId == UserId)
            ?? throw new KeyNotFoundException("Account not found");

        var reconciliation = new Reconciliation
        {
            Id = Guid.NewGuid(),
            AccountId = accountId,
            StatementDate = request.StatementDate,
            StatementBalance = request.StatementBalance
        };

        _db.Reconciliations.Add(reconciliation);
        await _db.SaveChangesAsync();

        var uncleared = await _db.Transactions
            .Include(t => t.Category)
            .Where(t => t.AccountId == accountId && t.Status != TransactionStatus.Reconciled && !t.IsVoid)
            .OrderByDescending(t => t.Date)
            .Select(t => new TransactionResponse(t.Id, t.AccountId, null, t.Date, t.Amount,
                t.PayeeId, t.PayeeName, t.CategoryId, t.Category != null ? t.Category.Name : null,
                t.Memo, t.ReferenceNumber, t.CheckNumber, t.Type, t.Status, t.IsVoid,
                t.TransferTransactionId, t.ImportBatchId, null, t.CreatedAt))
            .ToListAsync();

        var clearedBalance = await _db.Transactions
            .Where(t => t.AccountId == accountId && t.Status == TransactionStatus.Cleared && !t.IsVoid)
            .SumAsync(t => t.Amount);

        return Ok(new ReconciliationResponse(reconciliation.Id, accountId, request.StatementDate,
            request.StatementBalance, clearedBalance, request.StatementBalance - clearedBalance, false, uncleared));
    }

    [HttpPost("{accountId}/complete")]
    public async Task<ActionResult> Complete(Guid accountId, [FromQuery] Guid reconciliationId)
    {
        var rec = await _db.Reconciliations.FirstOrDefaultAsync(r => r.Id == reconciliationId && r.AccountId == accountId)
            ?? throw new KeyNotFoundException("Reconciliation not found");

        var clearedTxns = await _db.Transactions
            .Where(t => t.AccountId == accountId && t.Status == TransactionStatus.Cleared && !t.IsVoid)
            .ToListAsync();

        foreach (var txn in clearedTxns)
        {
            txn.Status = TransactionStatus.Reconciled;
            txn.ReconciliationId = reconciliationId;
        }

        rec.IsCompleted = true;
        rec.CompletedAt = DateTime.UtcNow;
        await _db.SaveChangesAsync();

        return NoContent();
    }

    [HttpPost("{accountId}/cancel")]
    public async Task<ActionResult> Cancel(Guid accountId, [FromQuery] Guid reconciliationId)
    {
        var rec = await _db.Reconciliations.FirstOrDefaultAsync(r => r.Id == reconciliationId && r.AccountId == accountId && !r.IsCompleted)
            ?? throw new KeyNotFoundException("Reconciliation not found");

        _db.Reconciliations.Remove(rec);
        await _db.SaveChangesAsync();

        return NoContent();
    }
}