using System.Security.Claims;
using foodmarket.Domain.Common;
using foodmarket.Infrastructure.Persistence;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace foodmarket.Api.Controllers.Common;

/// <summary>Sprint 19: CRUD сохранённых пользовательских пресетов фильтров.
/// Per-user внутри org: пользователь видит/правит только свои пресеты.
/// Tenant-isolation — стандартный query-filter; per-user — здесь на уровне
/// контроллера через WHERE UserId = currentUserId.</summary>
[ApiController]
[Authorize]
[Route("api/user/presets")]
public class UserPresetsController : ControllerBase
{
    private readonly AppDbContext _db;
    public UserPresetsController(AppDbContext db) => _db = db;

    public record PresetDto(Guid Id, string PageKey, string Name, string ConfigJson, DateTime UpdatedAt);
    public record CreateRequest(string PageKey, string Name, string ConfigJson);
    public record UpdateRequest(string Name, string ConfigJson);

    private Guid? CurrentUserId()
    {
        var raw = User.FindFirstValue(ClaimTypes.NameIdentifier) ?? User.FindFirstValue("sub");
        return Guid.TryParse(raw, out var id) ? id : null;
    }

    [HttpGet]
    public async Task<ActionResult<IReadOnlyList<PresetDto>>> List(
        [FromQuery] string? pageKey, CancellationToken ct)
    {
        var userId = CurrentUserId();
        if (userId is null) return Forbid();

        var q = _db.UserPresets.AsNoTracking().Where(p => p.UserId == userId);
        if (!string.IsNullOrWhiteSpace(pageKey)) q = q.Where(p => p.PageKey == pageKey);

        var items = await q.OrderBy(p => p.Name)
            .Select(p => new PresetDto(p.Id, p.PageKey, p.Name, p.ConfigJson, p.UpdatedAt))
            .ToListAsync(ct);
        return items;
    }

    [HttpPost]
    public async Task<ActionResult<PresetDto>> Create([FromBody] CreateRequest req, CancellationToken ct)
    {
        var userId = CurrentUserId();
        if (userId is null) return Forbid();
        if (string.IsNullOrWhiteSpace(req.PageKey))
            return BadRequest(new { error = "pageKey обязателен." });
        if (string.IsNullOrWhiteSpace(req.Name))
            return BadRequest(new { error = "Имя пресета обязательно." });
        // ConfigJson — schema-less, но должен быть валидным JSON
        // (требование jsonb-колонки). Пустые → "{}".
        var json = string.IsNullOrWhiteSpace(req.ConfigJson) ? "{}" : req.ConfigJson;
        try { System.Text.Json.JsonDocument.Parse(json); }
        catch { return BadRequest(new { error = "configJson должен быть валидным JSON." }); }

        var entity = new UserPreset
        {
            UserId = userId.Value,
            PageKey = req.PageKey.Trim(),
            Name = req.Name.Trim(),
            ConfigJson = json,
            UpdatedAt = DateTime.UtcNow,
        };
        _db.UserPresets.Add(entity);
        try
        {
            await _db.SaveChangesAsync(ct);
        }
        catch (DbUpdateException ex) when (ex.InnerException?.Message.Contains("IX_user_presets_Org_User_PageKey_Name") == true)
        {
            return Conflict(new { error = "Пресет с таким именем уже существует на этой странице." });
        }
        return new PresetDto(entity.Id, entity.PageKey, entity.Name, entity.ConfigJson, entity.UpdatedAt);
    }

    [HttpPut("{id:guid}")]
    public async Task<ActionResult<PresetDto>> Update(Guid id, [FromBody] UpdateRequest req, CancellationToken ct)
    {
        var userId = CurrentUserId();
        if (userId is null) return Forbid();
        var e = await _db.UserPresets.FirstOrDefaultAsync(p => p.Id == id && p.UserId == userId, ct);
        if (e is null) return NotFound();
        if (!string.IsNullOrWhiteSpace(req.Name)) e.Name = req.Name.Trim();
        if (!string.IsNullOrWhiteSpace(req.ConfigJson))
        {
            try { System.Text.Json.JsonDocument.Parse(req.ConfigJson); }
            catch { return BadRequest(new { error = "configJson должен быть валидным JSON." }); }
            e.ConfigJson = req.ConfigJson;
        }
        e.UpdatedAt = DateTime.UtcNow;
        try
        {
            await _db.SaveChangesAsync(ct);
        }
        catch (DbUpdateException ex) when (ex.InnerException?.Message.Contains("IX_user_presets_Org_User_PageKey_Name") == true)
        {
            return Conflict(new { error = "Пресет с таким именем уже существует на этой странице." });
        }
        return new PresetDto(e.Id, e.PageKey, e.Name, e.ConfigJson, e.UpdatedAt);
    }

    [HttpDelete("{id:guid}")]
    public async Task<IActionResult> Delete(Guid id, CancellationToken ct)
    {
        var userId = CurrentUserId();
        if (userId is null) return Forbid();
        var e = await _db.UserPresets.FirstOrDefaultAsync(p => p.Id == id && p.UserId == userId, ct);
        if (e is null) return NotFound();
        _db.UserPresets.Remove(e);
        await _db.SaveChangesAsync(ct);
        return NoContent();
    }
}