package io.trygvis.queue;

import java.util.Date;
import java.util.List;

import static io.trygvis.queue.Task.TaskState.*;
import static java.util.Arrays.asList;

public class Task {

    public enum TaskState {
        NEW,
        PROCESSING,
        OK,
        FAILED
    }

    private final long id;

    public final Long parent;

    public final String queue;

    public final TaskState state;

    public final Date scheduled;

    public final Date lastRun;

    public final int runCount;

    public final Date completed;

    public final List<String> arguments;

    public Task(long id, Long parent, String queue, TaskState state, Date scheduled, Date lastRun, int runCount, Date completed, List<String> arguments) {
        this.id = id;
        this.parent = parent;
        this.queue = queue;
        this.state = state;
        this.scheduled = scheduled;
        this.lastRun = lastRun;
        this.runCount = runCount;
        this.completed = completed;

        this.arguments = arguments;
    }

    public Task markProcessing() {
        return new Task(id, parent, queue, PROCESSING, scheduled, new Date(), runCount + 1, completed, arguments);
    }

    public Task markOk(Date completed) {
        return new Task(id, parent, queue, OK, scheduled, lastRun, runCount, completed, arguments);
    }

    public Task markFailed(Date now) {
        return new Task(id, parent, queue, FAILED, scheduled, lastRun, runCount, completed, arguments);
    }

    public String toString() {
        return "Task{" +
                "id=" + id +
                ", parent=" + parent +
                ", queue=" + queue +
                ", state=" + state +
                ", scheduled=" + scheduled +
                ", lastRun=" + lastRun +
                ", runCount=" + runCount +
                ", completed=" + completed +
                ", arguments='" + arguments + '\'' +
                '}';
    }

    public long id() {
        if (id == 0) {
            throw new RuntimeException("This task has not been persisted yet.");
        }

        return id;
    }

    public boolean isDone() {
        return completed != null;
    }

    public Task childTask(String queue, Date scheduled, String... arguments) {
        return new Task(0, id(), queue, NEW, scheduled, null, 0, null, asList(arguments));
    }

    public static Task newTask(String queue, Date scheduled, String... arguments) {
        return new Task(0, null, queue, NEW, scheduled, null, 0, null, asList(arguments));
    }

    public static Task newTask(String queue, Date scheduled, List<String> arguments) {
        return new Task(0, null, queue, NEW, scheduled, null, 0, null, arguments);
    }

    public static List<String> stringToArguments(String arguments) {
        return asList(arguments.split(","));
    }

    public static String argumentsToString(List<String> arguments) {
        StringBuilder builder = new StringBuilder();
        for (int i = 0, argumentsLength = arguments.size(); i < argumentsLength; i++) {
            String argument = arguments.get(i);
            if (argument.contains(",")) {
                throw new RuntimeException("The argument string can't contain a comma.");
            }
            if (i > 0) {
                builder.append(',');
            }
            builder.append(argument);
        }
        return builder.toString();
    }
}