# Copyright (C) 2017 Canonical Ltd.
#
# This file is part of cloud-init. See LICENSE file for license information.

import argparse
import re
import sys
from datetime import datetime
from typing import IO

from cloudinit.analyze import dump, show
from cloudinit.atomic_helper import json_dumps


def get_parser(parser=None):
    if not parser:
        parser = argparse.ArgumentParser(
            prog="cloudinit-analyze",
            description="Devel tool: Analyze cloud-init logs and data",
        )
    subparsers = parser.add_subparsers(title="Subcommands", dest="subcommand")
    subparsers.required = True

    parser_blame = subparsers.add_parser(
        "blame", help="Print list of executed stages ordered by time to init"
    )
    parser_blame.add_argument(
        "-i",
        "--infile",
        action="store",
        dest="infile",
        default="/var/log/cloud-init.log",
        help="specify where to read input.",
    )
    parser_blame.add_argument(
        "-o",
        "--outfile",
        action="store",
        dest="outfile",
        default="-",
        help="specify where to write output. ",
    )
    parser_blame.set_defaults(action=("blame", analyze_blame))

    parser_show = subparsers.add_parser(
        "show", help="Print list of in-order events during execution"
    )
    parser_show.add_argument(
        "-f",
        "--format",
        action="store",
        dest="print_format",
        default="%I%D @%Es +%ds",
        help="specify formatting of output.",
    )
    parser_show.add_argument(
        "-i",
        "--infile",
        action="store",
        dest="infile",
        default="/var/log/cloud-init.log",
        help="specify where to read input.",
    )
    parser_show.add_argument(
        "-o",
        "--outfile",
        action="store",
        dest="outfile",
        default="-",
        help="specify where to write output.",
    )
    parser_show.set_defaults(action=("show", analyze_show))
    parser_dump = subparsers.add_parser(
        "dump", help="Dump cloud-init events in JSON format"
    )
    parser_dump.add_argument(
        "-i",
        "--infile",
        action="store",
        dest="infile",
        default="/var/log/cloud-init.log",
        help="specify where to read input. ",
    )
    parser_dump.add_argument(
        "-o",
        "--outfile",
        action="store",
        dest="outfile",
        default="-",
        help="specify where to write output. ",
    )
    parser_dump.set_defaults(action=("dump", analyze_dump))
    parser_boot = subparsers.add_parser(
        "boot", help="Print list of boot times for kernel and cloud-init"
    )
    parser_boot.add_argument(
        "-i",
        "--infile",
        action="store",
        dest="infile",
        default="/var/log/cloud-init.log",
        help="specify where to read input. ",
    )
    parser_boot.add_argument(
        "-o",
        "--outfile",
        action="store",
        dest="outfile",
        default="-",
        help="specify where to write output.",
    )
    parser_boot.set_defaults(action=("boot", analyze_boot))
    return parser


def analyze_boot(name, args):
    """Report a list of how long different boot operations took.

    For Example:
    -- Most Recent Boot Record --
        Kernel Started at: <time>
        Kernel ended boot at: <time>
        Kernel time to boot (seconds): <time>
        Cloud-init activated by systemd at: <time>
        Time between Kernel end boot and Cloud-init activation (seconds):<time>
        Cloud-init start: <time>
    """
    infh, outfh = configure_io(args)
    kernel_info = show.dist_check_timestamp()
    status_code, kernel_start, kernel_end, ci_sysd_start = kernel_info
    kernel_start_timestamp = datetime.utcfromtimestamp(kernel_start)
    kernel_end_timestamp = datetime.utcfromtimestamp(kernel_end)
    ci_sysd_start_timestamp = datetime.utcfromtimestamp(ci_sysd_start)
    try:
        last_init_local = [
            e
            for e in _get_events(infh)
            if e["name"] == "init-local"
            and "starting search" in e["description"]
        ][-1]
        ci_start = datetime.utcfromtimestamp(last_init_local["timestamp"])
    except IndexError:
        ci_start = "Could not find init-local log-line in cloud-init.log"
        status_code = show.FAIL_CODE

    FAILURE_MSG = (
        "Your Linux distro or container does not support this "
        "functionality.\n"
        "You must be running a Kernel Telemetry supported "
        "distro.\nPlease check "
        "https://cloudinit.readthedocs.io/en/latest"
        "/topics/analyze.html for more "
        "information on supported distros.\n"
    )

    SUCCESS_MSG = (
        "-- Most Recent Boot Record --\n"
        "    Kernel Started at: {k_s_t}\n"
        "    Kernel ended boot at: {k_e_t}\n"
        "    Kernel time to boot (seconds): {k_r}\n"
        "    Cloud-init activated by systemd at: {ci_sysd_t}\n"
        "    Time between Kernel end boot and Cloud-init "
        "activation (seconds): {bt_r}\n"
        "    Cloud-init start: {ci_start}\n"
    )

    CONTAINER_MSG = (
        "-- Most Recent Container Boot Record --\n"
        "    Container started at: {k_s_t}\n"
        "    Cloud-init activated by systemd at: {ci_sysd_t}\n"
        "    Cloud-init start: {ci_start}\n"
    )
    status_map = {
        show.FAIL_CODE: FAILURE_MSG,
        show.CONTAINER_CODE: CONTAINER_MSG,
        show.SUCCESS_CODE: SUCCESS_MSG,
    }

    kernel_runtime = kernel_end - kernel_start
    between_process_runtime = ci_sysd_start - kernel_end

    kwargs = {
        "k_s_t": kernel_start_timestamp,
        "k_e_t": kernel_end_timestamp,
        "k_r": kernel_runtime,
        "bt_r": between_process_runtime,
        "k_e": kernel_end,
        "k_s": kernel_start,
        "ci_sysd": ci_sysd_start,
        "ci_sysd_t": ci_sysd_start_timestamp,
        "ci_start": ci_start,
    }

    outfh.write(status_map[status_code].format(**kwargs))
    clean_io(infh, outfh)
    return status_code


def analyze_blame(name, args):
    """Report a list of records sorted by largest time delta.

    For example:
      30.210s (init-local) searching for datasource
       8.706s (init-network) reading and applying user-data
        166ms (modules-config) ....
        807us (modules-final) ...

    We generate event records parsing cloud-init logs, formatting the output
    and sorting by record data ('delta')
    """
    infh, outfh = configure_io(args)
    blame_format = "     %ds (%n)"
    r = re.compile(r"(^\s+\d+\.\d+)", re.MULTILINE)
    idx = 0
    for idx, record in enumerate(
        show.show_events(_get_events(infh), blame_format)
    ):
        srecs = sorted(filter(r.match, record), reverse=True)
        outfh.write("-- Boot Record %02d --\n" % (idx + 1))
        outfh.write("\n".join(srecs) + "\n")
        outfh.write("\n")
    outfh.write("%d boot records analyzed\n" % (idx + 1))
    clean_io(infh, outfh)


def analyze_show(name, args):
    """Generate output records using the 'standard' format to printing events.

    Example output follows:
        Starting stage: (init-local)
          ...
        Finished stage: (init-local) 0.105195 seconds

        Starting stage: (init-network)
          ...
        Finished stage: (init-network) 0.339024 seconds

        Starting stage: (modules-config)
          ...
        Finished stage: (modules-config) 0.NNN seconds

        Starting stage: (modules-final)
          ...
        Finished stage: (modules-final) 0.NNN seconds
    """
    infh, outfh = configure_io(args)
    for idx, record in enumerate(
        show.show_events(_get_events(infh), args.print_format)
    ):
        outfh.write("-- Boot Record %02d --\n" % (idx + 1))
        outfh.write(
            "The total time elapsed since completing an event is"
            ' printed after the "@" character.\n'
        )
        outfh.write(
            'The time the event takes is printed after the "+" character.\n\n'
        )
        outfh.write("\n".join(record) + "\n")
    outfh.write("%d boot records analyzed\n" % (idx + 1))
    clean_io(infh, outfh)


def analyze_dump(name, args):
    """Dump cloud-init events in json format"""
    infh, outfh = configure_io(args)
    outfh.write(json_dumps(_get_events(infh)) + "\n")
    clean_io(infh, outfh)


def _get_events(infile):
    rawdata = None
    events, rawdata = show.load_events_infile(infile)
    if not events:
        events, _ = dump.dump_events(rawdata=rawdata)
    return events


def configure_io(args):
    """Common parsing and setup of input/output files"""
    if args.infile == "-":
        infh = sys.stdin
    else:
        try:
            infh = open(args.infile, "r")
        except OSError:
            sys.stderr.write("Cannot open file %s\n" % args.infile)
            sys.exit(1)

    if args.outfile == "-":
        outfh = sys.stdout
    else:
        try:
            outfh = open(args.outfile, "w")
        except OSError:
            sys.stderr.write("Cannot open file %s\n" % args.outfile)
            sys.exit(1)

    return infh, outfh


def clean_io(*file_handles: IO) -> None:
    """close filehandles"""
    for file_handle in file_handles:
        if file_handle in (sys.stdin, sys.stdout):
            continue
        file_handle.close()


if __name__ == "__main__":
    parser = get_parser()
    args = parser.parse_args()
    (name, action_functor) = args.action
    action_functor(name, args)
