using System.Text.Json;
using LiveRecorder.Domain.Enums;

namespace LiveRecorder.Domain.Entities;

public class CleanupOperation
{
    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web);

    private CleanupOperation()
    {
    }

    public CleanupOperation(
        CleanupOperationKind kind,
        bool deleteFiles,
        string? filtersJson,
        DateTimeOffset createdAt)
    {
        Id = Guid.NewGuid();
        Kind = kind;
        Status = CleanupOperationStatus.Queued;
        DeleteFiles = deleteFiles;
        FiltersJson = string.IsNullOrWhiteSpace(filtersJson) ? "{}" : filtersJson;
        WarningsJson = "[]";
        CreatedAt = createdAt;
    }

    public Guid Id { get; private set; }

    public CleanupOperationKind Kind { get; private set; }

    public CleanupOperationStatus Status { get; private set; }

    public bool DeleteFiles { get; private set; }

    public string FiltersJson { get; private set; } = "{}";

    public DateTimeOffset CreatedAt { get; private set; }

    public DateTimeOffset? StartedAt { get; private set; }

    public DateTimeOffset? CompletedAt { get; private set; }

    public int TotalSessionCount { get; private set; }

    public int ProcessedSessionCount { get; private set; }

    public int DeletedSessionCount { get; private set; }

    public int DeletedTaskCount { get; private set; }

    public int DeletedResultCount { get; private set; }

    public int DeletedLogCount { get; private set; }

    public int DeletedFileCount { get; private set; }

    public int DeletedDanmakuFileCount { get; private set; }

    public string WarningsJson { get; private set; } = "[]";

    public string? ErrorMessage { get; private set; }

    public void MarkRunning(DateTimeOffset startedAt)
    {
        Status = CleanupOperationStatus.Running;
        StartedAt = startedAt;
        CompletedAt = null;
        ErrorMessage = null;
    }

    public void SetTotalSessionCount(int totalSessionCount)
    {
        TotalSessionCount = Math.Max(0, totalSessionCount);
        if (ProcessedSessionCount > TotalSessionCount)
        {
            ProcessedSessionCount = TotalSessionCount;
        }
    }

    public void MarkCompleted(DateTimeOffset completedAt)
    {
        Status = CleanupOperationStatus.Completed;
        CompletedAt = completedAt;
        ErrorMessage = null;
    }

    public void MarkFailed(string errorMessage, DateTimeOffset completedAt)
    {
        Status = CleanupOperationStatus.Failed;
        CompletedAt = completedAt;
        ErrorMessage = string.IsNullOrWhiteSpace(errorMessage)
            ? "Cleanup operation failed."
            : errorMessage.Trim();
    }

    public void Requeue(string warning)
    {
        Status = CleanupOperationStatus.Queued;
        StartedAt = null;
        CompletedAt = null;
        ErrorMessage = null;
        AppendWarnings([warning]);
    }

    public void ApplyBatchProgress(
        int processedSessionCount,
        int deletedSessionCount,
        int deletedTaskCount,
        int deletedResultCount,
        int deletedLogCount,
        int deletedFileCount,
        int deletedDanmakuFileCount,
        IReadOnlyCollection<string>? warnings = null)
    {
        ProcessedSessionCount += Math.Max(0, processedSessionCount);
        DeletedSessionCount += Math.Max(0, deletedSessionCount);
        DeletedTaskCount += Math.Max(0, deletedTaskCount);
        DeletedResultCount += Math.Max(0, deletedResultCount);
        DeletedLogCount += Math.Max(0, deletedLogCount);
        DeletedFileCount += Math.Max(0, deletedFileCount);
        DeletedDanmakuFileCount += Math.Max(0, deletedDanmakuFileCount);

        if (ProcessedSessionCount > TotalSessionCount)
        {
            ProcessedSessionCount = TotalSessionCount;
        }

        if (warnings is { Count: > 0 })
        {
            AppendWarnings(warnings);
        }
    }

    public IReadOnlyList<string> GetWarnings()
    {
        if (string.IsNullOrWhiteSpace(WarningsJson))
        {
            return [];
        }

        try
        {
            return JsonSerializer.Deserialize<List<string>>(WarningsJson, JsonOptions) ?? [];
        }
        catch
        {
            return [];
        }
    }

    private void AppendWarnings(IReadOnlyCollection<string> warnings)
    {
        if (warnings.Count == 0)
        {
            return;
        }

        var merged = GetWarnings().Concat(warnings.Where(static item => !string.IsNullOrWhiteSpace(item)))
            .Select(static item => item.Trim())
            .ToList();
        WarningsJson = JsonSerializer.Serialize(merged, JsonOptions);
    }
}