import CONSTRAINTS from "../shared/validation/constraints";
import ErrorTypes from "../utils/errorTypes";
import * as Resources from "../utils/resources";
import { handleJSONWithData, RequestData } from "../utils/resources";
import { getTasks, Task } from "../jobs/scheduler";
import { normalizeString } from "../shared/utils/strings";
import { forConstraint } from "../shared/validation/validator";
import type { Request, Response } from "express";
import {
    isString,
    isTaskSortField,
    TaskResponse,
    TaskSortField,
    TaskState,
    UnixTimestampSeconds,
} from "../types";
import { HttpHeader } from "../shared/utils/http";

const isValidId = forConstraint(CONSTRAINTS.id, false);

function toTaskResponse(task: Task): TaskResponse {
    return {
        id: task.id,
        name: task.name,
        description: task.description,
        schedule: task.schedule,
        runningSince:
            task.runningSince &&
            (task.runningSince.unix() as UnixTimestampSeconds),
        lastRunStarted:
            task.lastRunStarted &&
            (task.lastRunStarted.unix() as UnixTimestampSeconds),
        lastRunDuration: task.lastRunDuration || null,
        state: task.state,
        result:
            task.state !== TaskState.RUNNING && task.result
                ? task.result.state
                : null,
        message:
            task.state !== TaskState.RUNNING && task.result
                ? task.result.message || null
                : null,
        enabled: task.enabled,
    };
}

async function withValidTaskId(data: RequestData): Promise<string> {
    if (!isString(data.id)) {
        throw { data: "Missing task id.", type: ErrorTypes.badRequest };
    }
    const id = normalizeString(data.id);

    if (!isValidId(id)) {
        throw { data: "Invalid task id.", type: ErrorTypes.badRequest };
    }

    return id;
}

async function getTask(id: string): Promise<Task> {
    const tasks = getTasks();
    const task = tasks[id];

    if (!task) {
        throw { data: "Task not found.", type: ErrorTypes.notFound };
    }

    return task;
}

async function withTask(data: RequestData): Promise<Task> {
    const id = await withValidTaskId(data);
    return await getTask(id);
}

async function setTaskEnabled(
    data: RequestData,
    enable: boolean
): Promise<TaskResponse> {
    const task = await withTask(data);
    task.enabled = enable;
    return toTaskResponse(task);
}

async function doGetAll(
    req: Request
): Promise<{ total: number; pageTasks: Task[] }> {
    const restParams = await Resources.getValidRestParams("list", null, req);

    const tasks = Resources.sort<Task, TaskSortField>(
        Object.values(getTasks()),
        isTaskSortField,
        restParams
    );
    const filteredTasks = Resources.filter(
        tasks,
        ["id", "name", "schedule", "state"],
        restParams
    );

    const total = filteredTasks.length;
    const pageTasks = Resources.getPageEntities(filteredTasks, restParams);

    return {
        total,
        pageTasks,
    };
}

export function getAll(req: Request, res: Response): void {
    doGetAll(req)
        .then(({ total, pageTasks }) => {
            res.set(HttpHeader.X_TOTAL_COUNT, total.toString(10));
            Resources.success(res, pageTasks.map(toTaskResponse));
        })
        .catch((err) => Resources.error(res, err));
}

export const run = handleJSONWithData(async (data) => {
    const task = await withTask(data);

    if (task.runningSince) {
        throw { data: "Task already running.", type: ErrorTypes.conflict };
    }

    task.run();
    return toTaskResponse(task);
});

export const enable = handleJSONWithData(async (data) => {
    await setTaskEnabled(data, true);
});

export const disable = handleJSONWithData(async (data) => {
    await setTaskEnabled(data, false);
});