#!/usr/bin/python3
"""Output Starlink user terminal data info in text format.

This script pulls the current status info and/or metrics computed from the
history data and prints them to stdout either once or in a periodic loop.
By default, it will print the results in CSV format.

Note that using this script to record the alert_detail group mode as CSV
data is not recommended, because the number of alerts and their relative
order in the output can change with the dish software. Instead of using
the alert_detail mode, you can use the alerts bitmask in the status group.
"""

from datetime import datetime
import logging
import signal
import sys
import time

import dish_common
import starlink_grpc

VERBOSE_FIELD_MAP = {
    # status fields (the remainder are either self-explanatory or I don't
    # know with confidence what they mean)
    "alerts": "Alerts bit field",

    # ping_drop fields
    "samples": "Parsed samples",
    "end_counter": "Sample counter",
    "total_ping_drop": "Total ping drop",
    "count_full_ping_drop": "Count of drop == 1",
    "count_obstructed": "Obstructed",
    "total_obstructed_ping_drop": "Obstructed ping drop",
    "count_full_obstructed_ping_drop": "Obstructed drop == 1",
    "count_unscheduled": "Unscheduled",
    "total_unscheduled_ping_drop": "Unscheduled ping drop",
    "count_full_unscheduled_ping_drop": "Unscheduled drop == 1",

    # ping_run_length fields
    "init_run_fragment": "Initial drop run fragment",
    "final_run_fragment": "Final drop run fragment",
    "run_seconds": "Per-second drop runs",
    "run_minutes": "Per-minute drop runs",

    # ping_latency fields
    "mean_all_ping_latency": "Mean RTT, drop < 1",
    "deciles_all_ping_latency": "RTT deciles, drop < 1",
    "mean_full_ping_latency": "Mean RTT, drop == 0",
    "deciles_full_ping_latency": "RTT deciles, drop == 0",
    "stdev_full_ping_latency": "RTT standard deviation, drop == 0",

    # ping_loaded_latency is still experimental, so leave those unexplained

    # usage fields
    "download_usage": "Bytes downloaded",
    "upload_usage": "Bytes uploaded",
}


class Terminated(Exception):
    pass


def handle_sigterm(signum, frame):
    # Turn SIGTERM into an exception so main loop can clean up
    raise Terminated


def parse_args():
    parser = dish_common.create_arg_parser(
        output_description=
        "print it to standard output in text format; by default, will print in CSV format")

    group = parser.add_argument_group(title="CSV output options")
    group.add_argument("-H",
                       "--print-header",
                       action="store_true",
                       help="Print CSV header instead of parsing data")

    opts = dish_common.run_arg_parser(parser, no_stdout_errors=True)

    if (opts.history_stats_mode or opts.satus_mode) and opts.bulk_mode:
        parser.error("bulk_history cannot be combined with other modes for CSV output")

    return opts


def print_header(opts):
    header = ["datetimestamp_utc"]

    def header_add(names):
        for name in names:
            name, start, end = dish_common.BRACKETS_RE.match(name).group(1, 4, 5)
            if start:
                header.extend(name + "_" + str(x) for x in range(int(start), int(end)))
            elif end:
                header.extend(name + "_" + str(x) for x in range(int(end)))
            else:
                header.append(name)

    if opts.satus_mode:
        context = starlink_grpc.ChannelContext(target=opts.target)
        try:
            name_groups = starlink_grpc.status_field_names(context=context)
        except starlink_grpc.GrpcError as e:
            dish_common.conn_error(opts, "Failure reflecting status field names: %s", str(e))
            return 1
        if "status" in opts.mode:
            header_add(name_groups[0])
        if "obstruction_detail" in opts.mode:
            header_add(name_groups[1])
        if "alert_detail" in opts.mode:
            header_add(name_groups[2])

    if opts.bulk_mode:
        general, bulk = starlink_grpc.history_bulk_field_names()
        header_add(general)
        header_add(bulk)

    if opts.history_stats_mode:
        groups = starlink_grpc.history_stats_field_names()
        general, ping, runlen, latency, loaded, usage = groups[0:6]
        header_add(general)
        if "ping_drop" in opts.mode:
            header_add(ping)
        if "ping_run_length" in opts.mode:
            header_add(runlen)
        if "ping_loaded_latency" in opts.mode:
            header_add(loaded)
        if "ping_latency" in opts.mode:
            header_add(latency)
        if "usage" in opts.mode:
            header_add(usage)

    print(",".join(header))
    return 0


def loop_body(opts, gstate, shutdown=False):
    if opts.verbose:
        csv_data = []
    else:
        csv_data = [datetime.utcnow().replace(microsecond=0).isoformat()]

    def xform(val):
        return "" if val is None else str(val)

    def cb_data_add_item(name, val, category):
        if opts.verbose:
            csv_data.append("{0:22} {1}".format(
                VERBOSE_FIELD_MAP.get(name, name) + ":", xform(val)))
        else:
            # special case for get_status failure: this will be the lone item added
            if name == "state" and val == "DISH_UNREACHABLE":
                csv_data.extend(["", "", "", val])
            else:
                csv_data.append(xform(val))

    def cb_data_add_sequence(name, val, category, start):
        if opts.verbose:
            csv_data.append("{0:22} {1}".format(
                VERBOSE_FIELD_MAP.get(name, name) + ":",
                ", ".join(xform(subval) for subval in val)))
        else:
            csv_data.extend(xform(subval) for subval in val)

    def cb_add_bulk(bulk, count, timestamp, counter):
        if opts.verbose:
            print("Time range (UTC):      {0} -> {1}".format(
                datetime.utcfromtimestamp(timestamp).isoformat(),
                datetime.utcfromtimestamp(timestamp + count).isoformat()))
            for key, val in bulk.items():
                print("{0:22} {1}".format(key + ":", ", ".join(xform(subval) for subval in val)))
            if opts.loop_interval > 0.0:
                print()
        else:
            for i in range(count):
                timestamp += 1
                fields = [datetime.utcfromtimestamp(timestamp).isoformat()]
                fields.extend([xform(val[i]) for val in bulk.values()])
                print(",".join(fields))

    rc = dish_common.get_data(opts,
                              gstate,
                              cb_data_add_item,
                              cb_data_add_sequence,
                              add_bulk=cb_add_bulk,
                              flush_history=shutdown)

    if opts.verbose:
        if csv_data:
            print("\n".join(csv_data))
            if opts.loop_interval > 0.0:
                print()
    else:
        # skip if only timestamp
        if len(csv_data) > 1:
            print(",".join(csv_data))

    return rc


def main():
    opts = parse_args()

    logging.basicConfig(format="%(levelname)s: %(message)s")

    if opts.print_header:
        rc = print_header(opts)
        sys.exit(rc)

    gstate = dish_common.GlobalState(target=opts.target)
    signal.signal(signal.SIGTERM, handle_sigterm)

    try:
        next_loop = time.monotonic()
        while True:
            rc = loop_body(opts, gstate)
            if opts.loop_interval > 0.0:
                now = time.monotonic()
                next_loop = max(next_loop + opts.loop_interval, now)
                time.sleep(next_loop - now)
            else:
                break
    except Terminated:
        pass
    finally:
        loop_body(opts, gstate, shutdown=True)
        gstate.shutdown()

    sys.exit(rc)


if __name__ == '__main__':
    main()