package main

import (
	"fmt"
	"log"
	"math/rand"
	"net"
	"sync"
	"time"
)

type TaskHandler struct {
	// Using sync.Map instead of a regular map with mutex
	agentTasks sync.Map // Maps AgentID to a queue of tasks ([]Task)
}

var taskHandler = NewTaskHandler()

// Characters for generating random task IDs
var taskIDCharset = "0123456789"
var taskIDLength = 6

type Task struct {
	TaskID       string
	AgentID      string
	Type         string
	Args         string
	Arg1         string
	Arg2         string
	Arg3         string
	Payload      []byte
	OperatorConn net.Conn
	OperatorID   string
	Dispatched   bool // Tracks whether the task has been dispatched
}

// Initialize the random number generator with a seed
func init() {
	rand.New(rand.NewSource(time.Now().UnixNano()))
}

// generateTaskID creates a random 6-character alphanumeric task ID (lowercase)
func generateTaskID() string {
	b := make([]byte, taskIDLength)
	for i := range b {
		b[i] = taskIDCharset[rand.Intn(len(taskIDCharset))]
	}
	return string(b)
}

// NewAgentHandler initializes a new TaskHandler instance.
func NewTaskHandler() *TaskHandler {
	return &TaskHandler{}
}

// QueueTask queues a task for a specific agent.
func (th *TaskHandler) QueueTask(agentID string, operatorID string, taskType string, taskArgs string, moduleData []byte) string {
	var logMessage string
	var taskID string

	// Check if agent exists
	if _, ok := agents.Load(agentID); ok {
		// Generate a unique task ID
		taskID = generateTaskID()

		task := Task{
			TaskID:     taskID,
			AgentID:    agentID,
			Type:       taskType,
			Args:       taskArgs,
			Payload:    moduleData,
			OperatorID: operatorID,
			Dispatched: false,
		}

		// Get the current task queue or create a new one
		var tasks []Task
		if existingTasks, ok := th.agentTasks.Load(agentID); ok {
			tasks = existingTasks.([]Task)
		}

		// Append the new task and store back in the sync.Map
		tasks = append(tasks, task)
		th.agentTasks.Store(agentID, tasks)

		logMessage = fmt.Sprintf("Queued task #%s for agent %s: %s", taskID, agentID, taskType)

	} else {
		logMessage = fmt.Sprintf("Agent not found: %s", agentID)
	}

	// Log logMessage
	log.Print(logMessage)

	return taskID // Return the generated task ID
}

// GetNextTask retrieves the next undispatched task for an agent, if any.
func (th *TaskHandler) GetNextTask(agentID string) *Task {
	tasksInterface, exists := th.agentTasks.Load(agentID)
	if !exists {
		return nil
	}

	tasks := tasksInterface.([]Task)
	if len(tasks) == 0 {
		return nil
	}

	// Find the first undispatched task
	for i := range tasks {
		if !tasks[i].Dispatched {
			// Mark the task as dispatched
			tasks[i].Dispatched = true

			// Update the tasks in storage with the modified task
			th.agentTasks.Store(agentID, tasks)

			// Log that the task is being executed
			log.Printf("Agent %s fetched task: %s: %s", agentID, tasks[i].TaskID, tasks[i].Type)

			return &tasks[i]
		}
	}
	// No undispatched tasks found
	return nil
}

// ListTasks lists all queued tasks for a specific agent.
func (th *TaskHandler) ListTasks(agentID string) []Task {
	tasksInterface, exists := th.agentTasks.Load(agentID)
	if !exists {
		return []Task{} // Return empty slice if no tasks exist
	}

	return tasksInterface.([]Task)
}

// ClearTasks clears all tasks for a specific agent.
func (th *TaskHandler) ClearTasks(agentID string) {
	th.agentTasks.Delete(agentID)

	// Log message
	logMessage := fmt.Sprintf("Cleared tasks for agent %s", agentID)
	log.Print(logMessage)

	// Notify operators
	// SendMessageToAllOperators(logMessage)
}

// GetTaskByID finds a task by its ID for a given agent
func (th *TaskHandler) GetTaskByID(agentID string, taskID string) (*Task, bool) {
	tasksInterface, exists := th.agentTasks.Load(agentID)
	if !exists {
		return nil, false
	}

	tasks := tasksInterface.([]Task)
	for i, task := range tasks {
		if task.TaskID == taskID {
			return &tasks[i], true
		}
	}

	return nil, false
}

// RemoveTaskByID removes a specific task by its ID
func (th *TaskHandler) RemoveTaskByID(agentID string, taskID string) bool {
	tasksInterface, exists := th.agentTasks.Load(agentID)
	if !exists {
		return false
	}

	tasks := tasksInterface.([]Task)
	for i, task := range tasks {
		if task.TaskID == taskID {
			// Remove the task by slicing
			updatedTasks := append(tasks[:i], tasks[i+1:]...)

			// If there are still tasks, update the stored slice
			if len(updatedTasks) > 0 {
				th.agentTasks.Store(agentID, updatedTasks)
			} else {
				// If no tasks remain, delete the entry
				th.agentTasks.Delete(agentID)
			}

			log.Printf("Removed task %s for agent %s", taskID, agentID)
			return true
		}
	}

	return false
}

// GetOperatorConnByTaskID retrieves the operator connection associated with a task
func (th *TaskHandler) GetOperatorConnByTaskID(agentID string, taskID string) (net.Conn, bool) {
	task, found := th.GetTaskByID(agentID, taskID)
	if !found {
		return nil, false
	}

	// Get the operator connection
	operatorConn, exists := GetOperatorConn(task.OperatorID)
	return operatorConn, exists
}

// GetOperatorIDByTaskID retrieves the operator ID associated with a task
func (th *TaskHandler) GetOperatorIDByTaskID(agentID string, taskID string) (string, bool) {
	task, found := th.GetTaskByID(agentID, taskID)
	if !found {
		return "", false
	}

	return task.OperatorID, true
}

// MarkTaskComplete marks a task as complete and optionally removes it
func (th *TaskHandler) MarkTaskComplete(agentID string, taskID string, removeTask bool) bool {
	tasksInterface, exists := th.agentTasks.Load(agentID)
	if !exists {
		return false
	}

	tasks := tasksInterface.([]Task)
	for i, task := range tasks {
		if task.TaskID == taskID {
			if removeTask {
				// Remove the task by slicing
				updatedTasks := append(tasks[:i], tasks[i+1:]...)

				// If there are still tasks, update the stored slice
				if len(updatedTasks) > 0 {
					th.agentTasks.Store(agentID, updatedTasks)
				} else {
					// If no tasks remain, delete the entry
					th.agentTasks.Delete(agentID)
				}

				log.Printf("Task %s for agent %s marked as complete and removed", taskID, agentID)
			} else {
				// Just update the task status if we're keeping it
				log.Printf("Task %s for agent %s marked as complete", taskID, agentID)
			}
			return true
		}
	}

	return false
}

// GetTaskCount returns the count of all tasks and undispatched tasks for an agent
func (th *TaskHandler) GetTaskCount(agentID string) (total int, undispatched int) {
	tasksInterface, exists := th.agentTasks.Load(agentID)
	if !exists {
		return 0, 0
	}

	tasks := tasksInterface.([]Task)
	total = len(tasks)

	for _, task := range tasks {
		if !task.Dispatched {
			undispatched++
		}
	}

	return total, undispatched
}