================================================================================

POST /api/upload/
    Uploads a file to the server.

Parameters (http headers):
    Content-Disposition: attachment; filename=<filename>  -- a name of the file (see rfc6266).
    Authorization: license <user license>                 -- a user license

Returns (json):
    {
        "status": "success" | "error"
        "id": uploaded file id if the status is "success"
        "size" (int): the media file size in bytes if the status is "success"
        "duration" (float): the media file duration in seconds if the status is "success"
        "error": Error description if the status is "error"
    }

Examples:
    $ curl --url https://www.lalal.ai/api/upload/ --data-binary @any_file.mp3 --header "Content-Disposition: attachment; filename=any_file.mp3" --header "Authorization: license 14abcde0"
    {"status": "success", "id": "9a3ae258-7693-4046-87c2-ef577eb752bb", "duration": 435.05}

    $ curl --url https://www.lalal.ai/api/upload/ --data-binary @any_file.mp3
    {"status": "error", "error": "No file name (use the Content-Disposition header)"}

Notes:
    Upload limit is 2Gb if a request has a valid license in the Authorization header otherwise 1Gb




================================================================================

POST /api/preview/
    Puts a file in the preview queue (the first minute of vocals).

Parameters (form-urlencoded):
    id (str): File id obtained from /upload/ method.
    filter_type (int, optional): Number of postprocess iterations with MWF.
    webpush-callback (json, optional): Client data for sending push notifications.

Returns (json):
    {
        "status": "success" | "error"
        "error": Error description if the status is "error"
    }

Examples:
    $ curl --url https://www.lalal.ai/api/preview/ --form-string "id=9a3ae258-7693-4046-87c2-ef577eb752bb" --form-string "filter_type=2"
    {"status": "success"}

    $ curl --url https://www.lalal.ai/api/preview/
    {"status": "error", "error": "No file id"}




================================================================================

POST /api/split/
    Puts a file in the split queue (full media file splitting).

Parameters (http headers):
    Authorization: license <user license> -- a user license

Parameters (form-urlencoded):
    id (str): File id obtained from /upload/ method.
    filter_type (int, optional): Number of postprocess iterations with MWF.
    webpush-callback (json, optional): Client data for sending push notifications.

Returns (json):
    {
        "status": "success" | "error"
        "error": Error description if the status is "error"
    }

Examples:
    $ curl --url https://www.lalal.ai/api/split/ --form-string "id=9a3ae258-7693-4046-87c2-ef577eb752bb" --form-string "lisence=397ae4"
    {"status": "success"}

    $ curl --url https://www.lalal.ai/api/split/ --form-string "id=9a3ae258-7693-4046-87c2-ef577eb752bb"
    {"status": "error", "error": "No lisence"}




================================================================================

POST /api/cancel/
    Cancels the current task and sets the status to canceled for the task, if it exists and is running.

Parameters (form-urlencoded):
    id (str): File id obtained from /upload/ method.

Returns (json):
    {
        "status": "success" | "error"
        "error": Error description if the status is "error"
    }
Examples:
    $ curl --url https://www.lalal.ai/api/cancel/ --form-string "id=9a3ae258-7693-4046-87c2-ef577eb752bb"
    {"status": "success"}

    $ curl --url https://www.lalal.ai/api/cancel/ --form-string "id=9a3ae258-7693-4046-87c2"
    {"status": "error", "error": "Task not found"}




================================================================================

GET /api/check/
    Gets the file info, results of preview or split, a current task status, etc.

Parameters (query string):
    id (str): File id obtained from /upload/ method.

Returns (json):
    {
        "status": "success" | "error"
        "name": the file name if the status is "success"
        "size": the file size in bytes if the status is "success"
        "duration": the file duration in seconds if the status is "success"

        "preview" (nullable): {
            "vocals": a url of preview vocals,
            "vocals_size" (int): vocals file size in bytes,
            "accompaniment": a url of preview accompaniment,
            "accompaniment_size" (int): accompaniment file size in bytes
        }: if the status is "success" and the preview task has successfully completed

        "split" (nullable): {
            "vocals": a url of vocals,
            "vocals_size" (int): vocals file size in bytes,
            "accompaniment": a url of accompaniment,
            "accompaniment_size" (int): accompaniment file size in bytes
        } if the status is "success" and the split task has successfully completed

        "task" (nullable): {
            "name": "split" | "preview",
            "state": "success" | "error" | "progress" | "cancelled",
            "error" (nullable): Error description if the state is "error" or "cancelled",
            "progress" (int, nullable): a task progress (0..100) if the state is "progress",
        } if the status is "success" and some task has been invoked

        "error": Error description if the status is "error"
    }

Examples:
    $ curl --url https://www.lalal.ai/api/check/?id=9a3ae258-7693-4046-87c2-ef577eb752bb
    {"status": "success"}

    $ curl --url https://www.lalal.ai/api/check/?id=9a3ae258
    {"status": "error", "error": "Invalid file id"}




================================================================================

GET /billing/get-limits/
    Current limits of a user license.

Parameters (http headers):
    Authorization: license <user license> -- a user license

Returns (json):
    {
        "status": "success" | "error",
        "error": Error description if the status is "error",
        "uses_left" (int): processed tracks count,
        "duration_left" (int): total processed tracks duration in minutes,
    }

Examples:
    $ curl --url https://www.lalal.ai/billing/get-limits/ --header "Authorization: license d5394d17"
    {"status": "success", "uses_left": 19, "duration_left": 89}

    $ curl --url https://www.lalal.ai/billing/get-limits/ --header "Authorization: license d539"
    {"status": "error", "error": "License not found"}




================================================================================

GET /billing/get-licence/
    Current user license info.

Parameters (http headers):
    Authorization: license <user license> -- a user license

Returns (json):
    {
        "status": "success" | "error",
        "error": Error description if the status is "error",
        "key": license key,
        "option": license type,
        "email": user email,
        "process_count_used" (int): processed tracks count,
        "process_count_limit" (int): tracks count limit,
        "process_duration_used" (int): total processed tracks duration in minutes,
        "process_duration_limit" (int): total tracks duration limit,
    }

Examples:
    $ curl --url https://www.lalal.ai/billing/get-licence/ --header "Authorization: license d5394d17"
    {"status": "success", "key": "d5394d17", "option": "standard", "creation_time": "2020-08-26T12:11:15.028Z" ...

    $ curl --url https://www.lalal.ai/billing/get-licence/ --header "Authorization: license d539"
    {"status": "error", "error": "License not found"}