"""compare commits of logs in different branches

selecting the time range is based on file 'sync_branches'
which should be in the branch where logdif.py is running
"""

import sys
from subprocess import check_output

branches = sys.argv[1:]

commits = {}
log_no = {}
log_title = {}
cursor = {}

since_info = []

with open("sync_branches") as f:
    # a file containing
    #  YYYY-mm-dd <branch1> <branch2>
    # for each date the branches are synced
    for line in f:
        if line.strip():
            info = line.split()
            if set(branches) & set(info[1:]) == set(branches):
                since_info.append(info[0])

gitlog = ['git', 'log', '--oneline']
if since_info:
    since = sorted(since_info)[-1]
    print(f'commits since {since}')
    gitlog.append(f'--since-as-filter={sorted(since_info)[-1]}')
else:
    print(f'no info for {branches} found in file sync_branches')

for br in branches:
    cursor[br] = 0
    output = check_output(gitlog + [br])
    log_title[br] = bytitle = {}
    log_no[br] = byno = []
    no = 0
    for line in output.decode('utf-8').split('\n'):
        if line:
            hash, title = line.split(' ', 1)
            bytitle.setdefault(title, []).append([(no, hash)])
            byno.append([hash, title])
            no += 1


# find matches
for br, byno in log_no.items():
   for no, line in enumerate(byno):
      commits.setdefault(line[1], {}).setdefault(br, []).append((no, line))

ordered = {}
for title, info in commits.items():
    # sort the info dict by value
    ordered[title] = {b: v for v, b in sorted((v, b) for b, v in info.items())}

commits = ordered

cnt = [0]

def print_commit(line):
    if not line[1]:
        return  # title cleared: this line is already printed
    # print and mark line as already printed
    info = commits[line[1]]
    output = []
    title = line[1]
    for br in log_no:
       infolist = info.get(br)
       if infolist:
           no, iline = infolist.pop(0)
           if not infolist:
               info.pop(br)
           output.append(f'{no:3}:{iline[0]}')
           iline[1] = ''  # clear title
       else:
           output.append(' ' * 11)
    print(' '.join(output), title)
    cnt[0] += 1
    if cnt[0] % 50 == 0:
        input(f' {br0:11s} {br1:11s}')


(br0, log0), (br1, log1) = list(log_no.items())
no1 = 0
for no0, line0 in enumerate(log0):
    if line0[1]:  # line not yet printed
           infodict = commits[line0[1]]
           if len(infodict) > 1:  # found a match
               info0 = infodict[br1]
               # loop over commits in br1 until matched no
               no1end = info0[0][0]
               if no1end > no0:
                   for n in range(no0, no1end):
                       line1 = log1[n]
                       print_commit(line1)
                   no1 = no1end
           print_commit(line0)