split-branch.sh

#!/bin/bash

# Check if an argument is provided
if [ "$#" -ne 1 ]; then
    echo "Usage: $0 <number_of_branches>"
    exit 1
fi

# Number of branches to create
NUM_BRANCHES=$1

# Current branch name
CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)

# Master branch name
MASTER_BRANCH="master"

# Get the list of changed files compared to master
CHANGED_FILES=$(git diff --name-only $MASTER_BRANCH...$CURRENT_BRANCH)

# Count the number of changed files
NUM_FILES=$(echo "$CHANGED_FILES" | wc -l)

# Calculate number of files per branch
FILES_PER_BRANCH=$(( (NUM_FILES + NUM_BRANCHES - 1) / NUM_BRANCHES ))

# Check out the master branch
git checkout $MASTER_BRANCH

# Create branches and cherry-pick changes
for i in $(seq 1 $NUM_BRANCHES); do
    NEW_BRANCH="${CURRENT_BRANCH}-${i}"
    git checkout -b $NEW_BRANCH $MASTER_BRANCH

    # Calculate file range for this branch
    START=$(( (i - 1) * FILES_PER_BRANCH + 1 ))
    END=$(( i * FILES_PER_BRANCH ))

    # Get the subset of files for this branch
    FILES_TO_ADD=$(echo "$CHANGED_FILES" | sed -n "${START},${END}p")

    # Add and commit the files
    if [ ! -z "$FILES_TO_ADD" ]; then
        git checkout $CURRENT_BRANCH -- $FILES_TO_ADD
        git add $FILES_TO_ADD
        git commit -m "Added changes for $NEW_BRANCH from $CURRENT_BRANCH"
        git push origin HEAD:refs/for/master
    fi

    # Go back to master for next iteration
    git checkout $MASTER_BRANCH
done

# Go back to the original branch
git checkout $CURRENT_BRANCH

echo "Created $NUM_BRANCHES branches off $MASTER_BRANCH with distributed changes from $CURRENT_BRANCH."