using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
using Microsoft.EntityFrameworkCore;
using SIFinance.Modules.SousTraitants.Dtos;
using SIFinance.Shared;
using SIFinance.Shared.Entities;

namespace SIFinance.Modules.SousTraitants.Endpoints;

public static class ContratsPrestatairesEndpoints
{
    public static IEndpointRouteBuilder MapContratsPrestatairesEndpoints(this IEndpointRouteBuilder app)
    {
        var group = app.MapGroup("/api/soustraitants/contrats").WithTags("SousTraitants-Contrats").RequireAuthorization();

        group.MapGet("", async (SIFinanceDbContext db, CancellationToken ct) =>
            await db.ContratsPrestataires
                .AsNoTracking()
                .Include(c => c.Organisme)
                .OrderByDescending(c => c.DateCreation)
                .Select(c => ToDto(c))
                .ToListAsync(ct));

        group.MapPost("", async (ContratPrestataireCreateDto input, SIFinanceDbContext db, CurrentUserService currentUser, CancellationToken ct) =>
        {
            if (string.IsNullOrWhiteSpace(input.Objet))
                return Results.BadRequest(new { error = "L'objet du contrat est requis." });
            if (input.DateFin < input.DateDebut)
                return Results.BadRequest(new { error = "La date de fin doit être postérieure à la date de début." });

            var contrat = new ContratPrestataire
            {
                OrganismeId = input.OrganismeId,
                Reference = await GenererReferenceAsync(db, ct),
                Objet = input.Objet.Trim(),
                DateSignature = input.DateSignature,
                DateDebut = input.DateDebut,
                DateFin = input.DateFin,
                MontantTotal = input.MontantTotal,
                Statut = "ACTIF",
                SaisieParId = await currentUser.GetOrCreateCurrentUserIdAsync(ct),
                DateCreation = DateTime.UtcNow,
            };

            db.ContratsPrestataires.Add(contrat);
            try
            {
                await db.SaveChangesAsync(ct);
            }
            catch (DbUpdateException ex)
            {
                return Results.BadRequest(new { error = "Impossible d'enregistrer le contrat — vérifiez l'organisme.", detail = ex.InnerException?.Message ?? ex.Message });
            }

            await db.Entry(contrat).Reference(c => c.Organisme).LoadAsync(ct);
            return Results.Created($"/api/soustraitants/contrats/{contrat.Id}", ToDto(contrat));
        });

        return app;
    }

    private static async Task<string> GenererReferenceAsync(SIFinanceDbContext db, CancellationToken ct)
    {
        var prefix = $"ST-CONT-{DateTime.UtcNow.Year}-";
        var last = await db.ContratsPrestataires
            .Where(c => c.Reference.StartsWith(prefix))
            .OrderByDescending(c => c.Reference)
            .Select(c => c.Reference)
            .FirstOrDefaultAsync(ct);

        var nextSeq = 1;
        if (last is not null && int.TryParse(last.AsSpan(prefix.Length), out var lastSeq))
            nextSeq = lastSeq + 1;

        return $"{prefix}{nextSeq:D3}";
    }

    private static ContratPrestataireDto ToDto(ContratPrestataire c) => new(
        c.Id, c.OrganismeId, c.Organisme.RaisonSociale, c.Reference, c.Objet,
        c.DateSignature, c.DateDebut, c.DateFin, c.MontantTotal, c.Statut);
}