using System.Collections.Concurrent;
using AMREZ.EOP.Abstractions.Applications.Tenancy;
using AMREZ.EOP.Domain.Shared.Tenancy;

namespace AMREZ.EOP.Infrastructures.Tenancy;

/// <summary>
/// ศูนย์รวม mapping แบบไดนามิก:
/// - Tenants: slug/key -> TenantContext
/// - DomainToTenant: custom-domain -> tenantKey
/// - BaseDomains: ชุดโดเมนแพลตฟอร์มที่รองรับรูปแบบ *.basedomain (รองรับหลายอันได้)
/// คุณสามารถเติม/แก้ไขระหว่างรันงานผ่าน Admin API หรือ job reload จาก DB ได้เลย
/// </summary>
public sealed class TenantMap
{
    private readonly ConcurrentDictionary<string, TenantContext> _tenants = new(StringComparer.OrdinalIgnoreCase);
    private readonly ConcurrentDictionary<string, string> _domainToTenant = new(StringComparer.OrdinalIgnoreCase);
    private readonly ConcurrentDictionary<string, byte> _baseDomains = new(StringComparer.OrdinalIgnoreCase);

    // ====== Query ======
    public bool TryGetBySlug(string slug, out ITenantContext ctx)
    {
        if (_tenants.TryGetValue(slug, out var t))
        {
            ctx = t; return true;
        }
        ctx = null!; return false;
    }

    public bool TryGetByDomain(string domain, out ITenantContext ctx)
    {
        if (_domainToTenant.TryGetValue(domain, out var key) && _tenants.TryGetValue(key, out var t))
        { ctx = t; return true; }
        ctx = null!; return false;
    }

    public bool TryGetBaseDomainFor(string host, out string? baseDomain)
    {
        foreach (var kv in _baseDomains.Keys)
        {
            var bd = kv;
            if (host.EndsWith(bd, StringComparison.OrdinalIgnoreCase) && !host.Equals(bd, StringComparison.OrdinalIgnoreCase))
            { baseDomain = bd; return true; }
        }
        baseDomain = null; return false;
    }

    // ====== Admin / Reload ======
    public void UpsertTenant(string key, TenantContext ctx) => _tenants[key] = ctx;
    public bool RemoveTenant(string key) => _tenants.TryRemove(key, out _);

    public void MapDomain(string domain, string tenantKey) => _domainToTenant[domain.Trim().ToLowerInvariant()] = tenantKey;
    public bool UnmapDomain(string domain) => _domainToTenant.TryRemove(domain.Trim().ToLowerInvariant(), out _);

    public void AddBaseDomain(string baseDomain) => _baseDomains[baseDomain.Trim().ToLowerInvariant()] = 1;
    public bool RemoveBaseDomain(string baseDomain) => _baseDomains.TryRemove(baseDomain.Trim().ToLowerInvariant(), out _);
}