using Core.Entities;
using Data;
using Microsoft.EntityFrameworkCore;

namespace WebApp.Services;

public class PrintPresetService : IPrintPresetService
{
    private readonly AppDbContext _context;
    private readonly ILogger<PrintPresetService> _logger;

    public PrintPresetService(AppDbContext context, ILogger<PrintPresetService> logger)
    {
        _context = context;
        _logger = logger;
    }

    public async Task<IReadOnlyList<PrintPreset>> GetAllAsync(CancellationToken cancellationToken = default)
    {
        return await _context.PrintPresets
            .AsNoTracking()
            .OrderBy(p => p.Name)
            .ToListAsync(cancellationToken);
    }

    public async Task<PrintPreset?> GetAsync(int id, CancellationToken cancellationToken = default)
    {
        return await _context.PrintPresets
            .AsNoTracking()
            .FirstOrDefaultAsync(p => p.Id == id, cancellationToken);
    }

    public async Task<bool> NameExistsAsync(
        string name,
        int? excludeId = null,
        CancellationToken cancellationToken = default)
    {
        var trimmed = name.Trim();
        var query = _context.PrintPresets.AsNoTracking().Where(p => p.Name == trimmed);
        if (excludeId.HasValue)
            query = query.Where(p => p.Id != excludeId.Value);
        return await query.AnyAsync(cancellationToken);
    }

    public async Task<PrintPreset> CreateAsync(PrintPreset preset, CancellationToken cancellationToken = default)
    {
        preset.Name = preset.Name.Trim();
        preset.UpdatedAt = DateTime.UtcNow;
        preset.TemplateMarkdown ??= string.Empty;

        if (await NameExistsAsync(preset.Name, null, cancellationToken))
            throw new InvalidOperationException($"A print preset named '{preset.Name}' already exists.");

        _context.PrintPresets.Add(preset);
        await _context.SaveChangesAsync(cancellationToken);
        _logger.LogInformation("Print preset created: {PresetId} {Name}", preset.Id, preset.Name);
        return preset;
    }

    public async Task<PrintPreset> UpdateAsync(PrintPreset preset, CancellationToken cancellationToken = default)
    {
        var existing = await _context.PrintPresets
            .FirstOrDefaultAsync(p => p.Id == preset.Id, cancellationToken);

        if (existing is null)
            throw new InvalidOperationException($"Print preset {preset.Id} was not found.");

        var name = preset.Name.Trim();
        if (await NameExistsAsync(name, preset.Id, cancellationToken))
            throw new InvalidOperationException($"A print preset named '{name}' already exists.");

        existing.Name = name;
        existing.TemplateMarkdown = preset.TemplateMarkdown ?? string.Empty;
        existing.EntityType = preset.EntityType;
        existing.FiltersJson = preset.FiltersJson;
        existing.UpdatedAt = DateTime.UtcNow;

        await _context.SaveChangesAsync(cancellationToken);
        _logger.LogInformation("Print preset updated: {PresetId} {Name}", existing.Id, existing.Name);
        return existing;
    }

    public async Task DeleteAsync(int id, CancellationToken cancellationToken = default)
    {
        var existing = await _context.PrintPresets
            .FirstOrDefaultAsync(p => p.Id == id, cancellationToken);

        if (existing is null)
            return;

        _context.PrintPresets.Remove(existing);
        await _context.SaveChangesAsync(cancellationToken);
        _logger.LogInformation("Print preset deleted: {PresetId} {Name}", id, existing.Name);
    }
}