#!/usr/bin/env python

import argparse
import sys
import os.path

import cairo

from sched_trace import event_name, event_time, SchedTrace

import sched_trace.draw

def s2ns(secs):
    return secs * 1E9

def ms2ns(millis):
    return millis * 1E6

def ns2s(nanos):
    return nanos / 1E9

def parse_args():
    parser = argparse.ArgumentParser(
        description="Render a LITMUS^RT schedule trace as a PDF.")

    parser.add_argument('-o', '--output',
        help='name of the generated PDF file')

    parser.add_argument('-x', '--xscale', type=float, default=36,
        help="how many points (1/72'') per millisecond?")
    parser.add_argument('-y', '--yscale', type=float, default=72,
        help="how many points (1/72'') per task/core?")
    parser.add_argument('--margin', type=float, default=36,
        help="how many points (1/72'') of margin around the schedule?")

    parser.add_argument('--major-ticks', type=float, default=10,
        help="how many milliseconds per major tick? (zero means off)")
    parser.add_argument('--minor-ticks', type=float, default=1,
        help="how many milliseconds per minor tick? (zero means off)")

    parser.add_argument('-j', '--show-job-ids', action='store_true',
        help="show job IDs next to releases and completions")

    parser.add_argument('-f', '--from', type=float, dest='start',
        help='draw schedule starting at time TIME', metavar='TIME')
    parser.add_argument('-u', '--until', type=float, dest='end',
        help='draw schedule up to time TIME', metavar='TIME')
    parser.add_argument('-l', '--length', type=float, default=1000,
        help='draw schedule for LENGTH time units')
    parser.add_argument('-r', '--relative', action='store_true',
        help='interpret -f/-u options relative to system release')

    parser.add_argument('-v', '--verbose', action='store_true', default=False,
        help='output some information while drawing')

    parser.add_argument('file', nargs='*',
        help='the binary trace files collected with st-trace')

    return parser.parse_args()


def default_output_name(input_files):
    if not input_files:
        return 'schedule.pdf'
    candidate = input_files[0]
    for i in xrange(len(candidate)):
        if not all([f[i] == candidate[i] for f in input_files]):
            break
    candidate = os.path.basename(candidate[:i])
    if candidate.endswith('_cpu='):
        candidate = candidate.replace('_cpu=', '')
    if not candidate:
        return 'schedule.pdf'
    return candidate + '.pdf'

def main(args=sys.argv[1:]):
    opts = parse_args()

    if not opts.output:
        opts.output = default_output_name(opts.file)

    try:
        opts.file = [f for f in opts.file if os.stat(f).st_size > 0]
        trace = SchedTrace(opts.file)
    except IOError, msg:
        print 'Could not load trace files (%s)' % msg
        sys.exit(1)

    if opts.start:
        # convert from ms
        opts.start = ms2ns(opts.start)
        # check if a relative time is given
        if opts.relative:
            if trace.system_releases:
                opts.start += trace.system_releases[0]
            else:
                opts.start += trace.earliest_event_time

    if opts.end:
        # convert from ms
        opts.end = ms2ns(opts.end)
        # check if a relative time is given
        if opts.relative:
            if trace.system_releases:
                opts.end += trace.system_releases[0]
            else:
                opts.end += trace.earliest_event_time

    if not opts.start:
        if opts.end and opts.length:
            opts.start = opts.end - ms2ns(opts.length)
        elif trace.system_releases:
            opts.start = trace.system_releases[0]
        else:
            opts.start = trace.earliest_event_time

    if not opts.end:
        if opts.start and opts.length:
            opts.end = opts.start + ms2ns(opts.length)
        else:
            opts.end = trace.latest_event_time

    if opts.verbose:
        print '[II] Rendering into file: %s' % opts.output
        print '[II] Drawing %.2f seconds from time %.4fs until time %.4fs.' % \
            (ns2s(opts.end - opts.start), ns2s(opts.start), ns2s(opts.end))
        if len(trace.system_releases) == 1:
            print '[II] The trace contains a system release at time %.4fs.' % \
                (ns2s(trace.system_releases[0]))
        elif len(trace.system_releases) > 1:
            print '[!!] The trace contains multiple system releases: %s' % \
                (' '.join(['%.4fs' % ns2s(x) for x in trace.system_releases]))
        else:
            print '[II] The trace does not contain a system release.'

    sched_trace.draw.render(opts, trace)

#     for pid in trace.task_names:
#         print pid, '->', trace.task_names[pid], trace.task_wcets[pid], trace.task_periods[pid]

#     for (to, away) in trace.scheduling_intervals_in_range(trace.system_releases[0], trace.system_releases[0] + 1E9):
#         print to, away


if __name__ == '__main__':
    main()