#!/usr/bin/env python3

import matplotlib.pyplot as plt
import xdg
import re
import pycurl
import certifi
import os
import sys
from bs4 import BeautifulSoup
from io import BytesIO

# where we get the bench list from
# sadly message edits don't appear in the public archive so we have to
# download the gitlab raw logs too
# (maybe we should be getting the messages from the zulip API instead??)
archive = 'https://coq.gitlab.io/zulip-archive/stream/240008-GitHub-notifications/topic/Bench.20Notifications.html'

print ('Getting bench list.')
buffer = BytesIO()
c = pycurl.Curl()
c.setopt(c.URL, archive)
c.setopt(c.WRITEFUNCTION, buffer.write)
c.setopt(c.CAINFO, certifi.where())
c.perform()
c.close()
str = buffer.getvalue().decode('utf8')

print ('Parsing bench list.')

# parse HTML and remove tags
# NB since coq was made default language on zulip the tables are full of <span> tags
# so we really don't want to keep them
str = BeautifulSoup(str, "html.parser").text

# NB: the line with the date starts with a space
# (in the original there is the avatar broken image)
datere = re.compile(' Bench bot \((.*)\):')

jobre = re.compile('Bench at https://gitlab.com/coq/coq/-/jobs/(.*)$')

benches=[]
curdate=None

for line in iter(str.splitlines()):
    match = re.match(datere, line)
    if match:
        # Next post
        curdate = match[1]
    else:
        match = re.match(jobre, line)
        if match:
            job = match[1]
            benches += [(curdate, match[1])]

cachedir = xdg.xdg_cache_home() / "coq-bench-plotter"
os.makedirs(cachedir, exist_ok=True)

## download job logs
print ('Downloading job logs.')

m = pycurl.CurlMulti()
m.setopt(pycurl.M_MAX_HOST_CONNECTIONS, 8)

files=[]

for _, job in benches:
    fname = cachedir / (job + '.log')
    if not(os.path.exists(fname)):
        f = open(fname, 'xb') # x: will error if already exists
        files += [f]
        c = pycurl.Curl()
        c.setopt(c.URL, 'https://gitlab.com/coq/coq/-/jobs/' + job + '/raw')
        c.setopt(c.WRITEFUNCTION, f.write)
        c.setopt(c.CAINFO, certifi.where())
        c.setopt(c.FOLLOWLOCATION, True)
        m.add_handle(c)

num_handles = len(files)
while num_handles:
    print (f'Downloading {num_handles} log files.')
    ret = m.select(5.0)
    if ret == -1:
        continue
    while 1:
        ret, num_handles = m.perform()
        if ret != pycurl.E_CALL_MULTI_PERFORM:
            break

for f in files:
    f.flush()
    f.close()

## parse job logs
print ('Parsing job logs.')

# captures package name and OLD time
# the numerals are to avoid matching the table header
packre = re.compile('│[ ]+([^ ]+) │[ ]+[^ ]+[ ]+([0-9][^ ]*)[ ]+([^ ]+)')

parsed=[]
for date, job in benches:
    cur={}
    fname = cachedir / (job + '.log')
    with open(fname) as f:
        for l in f:
            match = re.match(packre, l)
            if match:
                # the table appears multiple times in the log so this may be overriding the value
                # that is OK (it's not worth bothering to find the last table)
                cur[match[1]] = (match[2], match[3])
    if cur:
        parsed += [(date, job, cur)]

def filter_to(packname):
    dates=[]
    jobs=[]
    times=[]
    changes=[]
    for date, job, packs in parsed:
        if packname in packs:
            dates += [date]
            jobs += [job]
            time, change = packs[packname]
            times += [float(time)]
            changes += [float(change)]
    return dates, jobs, times, changes

def plot(packname):
    dates, jobs, times, changes = filter_to(packname)
    # alternatively you can use dates for x axis, times for y axis
    # with x = jobs, if you find an interesting point, hover the mouse on it
    # pyplot will say somewhere in the window "x=..., y=..."
    # now if you don't want to read and type the whole 10 digit number
    # export as svg and search for the last 3 digits followed by a space
    # it should be easy to find a xml comment with the job number eg "<!-- 2100592270 -->"
    plt.plot(jobs, changes)
    plt.ylabel(packname)
    plt.show()

def list_packs():
    known={}
    for _, _, packs in parsed:
        for pack in packs.keys():
            if pack in known.keys():
                known[pack] += 1
            else:
                known[pack] = 1
    return known

plot(sys.argv[1])