# EonaCat.FluentScheduler

**EonaCat.FluentScheduler** is a **task scheduling library for C#** 
that combines **cron expressions** and **fluent scheduling**. 

It supports persistent tasks, retries, parallel execution, logging, and dynamic task management.

---

## Features

- **Fluent scheduling**: `EveryDayAt`, `EveryWeekOn`, `EveryMonthOn`, `EveryYearOn`  
- **Cron expressions**: full 6-part syntax with seconds, minutes, hours, day, month, weekday  
  - Supports ranges (`1-5`), lists (`1,2,3`), steps (`*/5`)  
- **Async-safe and parallel task execution**  
- **Retry mechanism** for failed tasks with configurable retry count and delay  
- **Persistent tasks** with automatic restoration on application restart  
- **Dynamic task management**: remove tasks at runtime  
- **Task status tracking**: Pending, Running, Success, Failed  
- **Optional logging** for monitoring task execution  

---

## Installation

```csharp
Install-Package EonaCat.FluentScheduler
```

---

## Usage

### 1. Fluent Scheduling

```csharp
using EonaCat.FluentScheduler;
using System;
using System.Threading.Tasks;

class Program
{
    static async Task Main()
    {
        // Daily task at 08:30
        FluentScheduler.Schedule(async () =>
        {
            Console.WriteLine($"Daily task executed at {DateTime.Now}");
        }).EveryDayAt(8, 30);

        // Weekly task on Monday at 09:00
        FluentScheduler.Schedule(async () =>
        {
            Console.WriteLine($"Weekly task executed at {DateTime.Now}");
        }).EveryWeekOn(DayOfWeek.Monday, 9, 0);

        Scheduler.Start();
        Console.ReadKey();
        Scheduler.Stop();
    }
}
```

# 2. Cron Scheduling

```csharp
FluentScheduler.ScheduleCron("Every5Sec", "*/5 * * * * *", async () =>
{
    Console.WriteLine($"Cron task executed every 5 seconds at {DateTime.Now}");
});
```

# 3. Logging and Retry
```csharp
Scheduler.SetLogger(Console.WriteLine);
```

# 4. Dynamic Task Removal
```csharp
// Remove a task by name
Scheduler.RemoveTask("Every5Sec");
```

# 5. Task Status Tracking
```csharp
foreach (var task in Scheduler.GetAllTasks())
{
    Console.WriteLine($"{task.Name}: Status={task.Status}, NextRun={task.NextRun}, LastRun={task.LastRun}, LastError={task.LastError}");
}
```

# 6. Retry Mechanism

* Default: 3 retries, 5 seconds delay
* Configurable via RetryCount and RetryDelaySeconds on ScheduledTask objects

## Cron Expression Format

```csharp
<second> <minute> <hour> <day> <month> <weekday>
```

* – any value

*/n – every n units

x-y – range

x,y,z – list of values

### Examples:

"0 30 8 * * 1" → Every Monday at 08:30:00

"*/10 * * * * *" → Every 10 seconds

### Persistence

* Tasks are automatically saved to tasks.json on disk.
* On restart, tasks are restored automatically.
* Action mapping is handled internally via registered task names.