# git demo. Scenario 2: Multiple developers and one remote shared repository.

# Scenario 2a : "user of a remote repository"

# first we move to a safe place:
cd /tmp

# we are interested in a remote repository. So we clone it.
git clone ssh://emanuele@escher.fuw.edu.pl/git/autumnschool/shared/sn
cd sn

# we can check that we have a git repository:
git status

# git keeps track of the URL of the remote repository:
git remote -v

# the code we have just retrieved is about social networks:
python social_network.py

# Since we cloned new updates could be sent by other developers to the
# remote repository...
git fetch

# we can have a look to the logs to have more details:
git log

# ...also from the log's graphical interface:
gitk --all

# after fetching updates we usually want to merge them to 
git merge origin/master

# Logs show the new commits:
git log

# executing the updated code shows what changed:
python social_network.py

# the graphical interface shows the merge action:
gitk --all

# Now we want to step back to how it was before the last commit.
git reset --hard HEAD~1 # or better use SHA1 or first clone

# Logs reflect we stepped back:
git log

# ...as well as the graphical interface:
gitk --all

# we can retrieve the latest updates and merge them in a single command:
git pull

# and verify that everything went well:
git log
gitk --all

# Scenario 2b: "local development of a remote project"
# Task1: create a new file in people/ called <name.surname>.txt
cat > people/emanuele.olivetti.txt <<EOF
laura gatti
nausicaa olivetti
sibilla olivetti
rike benjamin schuppner
EOF

# let's see our changes is action:
python social_network.py

# Now we commit our changes:
git add people/emanuele.olivetti.txt
git commit -m "Added Emanuele."

# The logs confirm our commit:
git log

# and we check that our local repository diverged from the remote one.
gitk --all

# Scenario 2c: "from local developer to contributor"
# WARNING: some changes could have been pushed remotely by other devels...
git push

# The error tells us that we must pull latest remote updates first:
git pull

# we see that new changes arrived and that we merged correctly.
gitk --all

# Executing the program shows the latest updates:
python social_network.py

# now we can push safely:
git push

# ...and see that how the logs reflect our push:
gitk --all

# Scenario 2d: conflicts!
# We want to add a new feature to the social network graph: a better title.
# WARNING: Someone else might have done it in remote repo after our
# last pull...
emacs social_network.py

# let's check the awesome new title:
python social_network.py

# let's commit it:
git commit social_network.py -m "Added cool title."

# We want to push our changes. We pull first:
git pull

# In order to solve the conflict we first edit the conflict:
emacs social_network.py

# and then check the code is OK:
python social_network.py

# we stage the solution of the conflict and commit it:
git add social_network.py
git commit -m "Fixed conflicting titles."

# so that we can push (and pull first!):
git pull
git push