using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using ZB.MOM.WW.LmxOpcUa.Host.Domain;

namespace ZB.MOM.WW.LmxOpcUa.Tests.Helpers
{
    /// <summary>
    /// In-memory Galaxy repository used by tests to control hierarchy rows, attribute rows, and deploy metadata without SQL access.
    /// </summary>
    public class FakeGalaxyRepository : IGalaxyRepository
    {
        /// <summary>
        /// Occurs when the fake repository simulates a Galaxy deploy change.
        /// </summary>
        public event Action? OnGalaxyChanged;

        /// <summary>
        /// Gets or sets the hierarchy rows returned to address-space construction logic.
        /// </summary>
        public List<GalaxyObjectInfo> Hierarchy { get; set; } = new List<GalaxyObjectInfo>();

        /// <summary>
        /// Gets or sets the attribute rows returned to address-space construction logic.
        /// </summary>
        public List<GalaxyAttributeInfo> Attributes { get; set; } = new List<GalaxyAttributeInfo>();

        /// <summary>
        /// Gets or sets the deploy timestamp returned to change-detection logic.
        /// </summary>
        public DateTime? LastDeployTime { get; set; } = DateTime.UtcNow;

        /// <summary>
        /// Gets or sets a value indicating whether connection checks should report success.
        /// </summary>
        public bool ConnectionSucceeds { get; set; } = true;

        /// <summary>
        /// Gets or sets a value indicating whether repository calls should throw to simulate database failures.
        /// </summary>
        public bool ShouldThrow { get; set; }

        /// <summary>
        /// Returns the configured hierarchy rows or throws to simulate a repository failure.
        /// </summary>
        /// <param name="ct">A cancellation token ignored by the in-memory fake.</param>
        /// <returns>The configured hierarchy rows.</returns>
        public Task<List<GalaxyObjectInfo>> GetHierarchyAsync(CancellationToken ct = default)
        {
            if (ShouldThrow) throw new Exception("Simulated DB failure");
            return Task.FromResult(Hierarchy);
        }

        /// <summary>
        /// Returns the configured attribute rows or throws to simulate a repository failure.
        /// </summary>
        /// <param name="ct">A cancellation token ignored by the in-memory fake.</param>
        /// <returns>The configured attribute rows.</returns>
        public Task<List<GalaxyAttributeInfo>> GetAttributesAsync(CancellationToken ct = default)
        {
            if (ShouldThrow) throw new Exception("Simulated DB failure");
            return Task.FromResult(Attributes);
        }

        /// <summary>
        /// Returns the configured deploy timestamp or throws to simulate a repository failure.
        /// </summary>
        /// <param name="ct">A cancellation token ignored by the in-memory fake.</param>
        /// <returns>The configured deploy timestamp.</returns>
        public Task<DateTime?> GetLastDeployTimeAsync(CancellationToken ct = default)
        {
            if (ShouldThrow) throw new Exception("Simulated DB failure");
            return Task.FromResult(LastDeployTime);
        }

        /// <summary>
        /// Returns the configured connection result or throws to simulate a repository failure.
        /// </summary>
        /// <param name="ct">A cancellation token ignored by the in-memory fake.</param>
        /// <returns>The configured connection result.</returns>
        public Task<bool> TestConnectionAsync(CancellationToken ct = default)
        {
            if (ShouldThrow) throw new Exception("Simulated DB failure");
            return Task.FromResult(ConnectionSucceeds);
        }

        /// <summary>
        /// Raises the deploy-change event so tests can trigger rebuild logic.
        /// </summary>
        public void RaiseGalaxyChanged() => OnGalaxyChanged?.Invoke();
    }
}