#! /usr/bin/env bash

#################################################################################
#
# Extract Github Wiki commits to transfer to another repo and keep commit history
#
#################################################################################

# Clone the two repositories to combine:
git clone https://github.com/docker-mailserver/docker-mailserver --single-branch
git clone https://github.com/docker-mailserver/docker-mailserver.wiki



#########################################################################################################################################
#
# `git-filter-repo` rewrites history to accomodate for any changes (file rename and location): https://github.com/newren/git-filter-repo
#
# May not be needed as commits of these changes without internal file content changes can usually be tracked by Git (`git log --follow`).
# Git continues to improve it's tracking over the years, eg: In 2021 with Git 2.31 (https://stackoverflow.com/a/36615639/11681500)
# Only Github's history view doesn't present history related to such changes. This is mostly an attempt to improve UX for contributors.
#
#########################################################################################################################################

# `git-filter-repo` commands will be run from this repo:
cd docker-mailserver.wiki

# No value in having mixed casing, rename all filenames to be lowercase:
git filter-repo --filename-callback 'return filename.lower()'

# These are Github Wiki specific, not required for porting:
# Similar to `rm _footer.md _sidebar.md` but doesn't require a commit, removes files from history entirely
git filter-repo --invert-paths --path '_footer.md' --path '_sidebar.md'

# Files are matched and relocated to directory hierarchy matching `_sidebar.md`:
# Many filenames are also modified for convenience
git filter-repo --paths-from-file ../rename-hierarchy.txt

# Migrate the content from top-level to a subdirectory:
# Equivalent to `--path-rename :docs/content/`
git filter-repo --to-subdirectory-filter docs/content/



#####################################################
#
# Copy over the commits while retaining their history
#
#####################################################

# Switch to the primary repo, create a branch for PR, add the local wiki repo as a remote:
cd ../docker-mailserver
git checkout -b docs/migrate-docs
git remote add wiki-local ../docker-mailserver.wiki

# Transfer the files (with commit history intact) from the `wiki-local` remote to the primary repo:
# `--allow-unrelated-histories` carries over the commit history
git fetch wiki-local
git merge --allow-unrelated-histories wiki-local/master

# Github Wiki uses flat hierarchy structure for files.
# This uses `--paths-from-file` to rename/relocate files
# Note `git-filter-repo` docs state you should filter paths before renaming them (didn't seem required here): https://github.com/newren/git-filter-repo/issues/96#issuecomment-786320550

home.md==>index.md

# Configuration
setup.sh.md==>config/setup.sh.md

regex:configure-(accounts|aliases)\.md$==>config/user-management/\1.md

regex:configure-(dkim|dmarc|spf|autodiscover)\.md$==>config/best-practices/\1.md

regex:configure-(ssl|fail2ban)\.md$==>config/security/\1.md
understanding-the-ports.md==>config/security/understanding-the-ports.md

faq-and-tips.md==>faq.md
regex:(debugging|faq)\.md$==>config/troubleshooting/\1.md

configure-pop3.md==>config/pop3.md


# Advanced
list-of-optional-config-files-&-directories.md==>advanced/optional-config.md
update-and-cleanup.md==>advanced/maintenance/update-and-cleanup.md

regex:override-default-(.*)-configuration\.md==>advanced/override-defaults/\1.md

configure-ldap.md==>advanced/auth-ldap.md

regex:.*(sieve|fetchmail).*\.md==>advanced/mail-\1.md
regex:configure-(aws-ses|relay-hosts)\.md==>advanced/mail-forwarding/\1.md

regex:.*(full-text-search|kubernetes|ipv6)\.md==>advanced/\1.md


# Tutorials

installation-examples.md==>tutorials/installation-examples.md


# Use Cases

forward-only-mailserver-with-ldap-authentication.md==>uses-cases/forward-only-mailserver-with-ldap-authentication.md