push_chunks.sh

#!/bin/bash

REPO_PATH=""
REMOTE_URL=""
SOURCE_BRANCH=""
TARGET_BRANCH=""
TEMP_BRANCH="temp"
CHUNK_SIZE=8000  # Number of commits per chunk

GREEN='\033[0;32m'
YELLOW='\033[1;33m'
RED='\033[0;31m'
NC='\033[0m'

print_status() {
    echo -e "${GREEN}[*] $1${NC}"
}

print_warning() {
    echo -e "${YELLOW}[!] $1${NC}"
}

print_error() {
    echo -e "${RED}[✗] $1${NC}"
}

cd "$REPO_PATH" || { print_error "Failed to change directory to $REPO_PATH"; exit 1; }
print_status "Working in repository: $(pwd)"

CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
if [ "$CURRENT_BRANCH" != "$SOURCE_BRANCH" ]; then
    print_warning "Current branch is $CURRENT_BRANCH, not $SOURCE_BRANCH"
    read -p "Switch to $SOURCE_BRANCH? (y/n) " -n 1 -r
    echo
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        git checkout "$SOURCE_BRANCH" || { print_error "Failed to checkout $SOURCE_BRANCH"; exit 1; }
    else
        print_error "Aborting as we're not on the correct branch"
        exit 1
    fi
fi

print_status "Creating temporary branch: $TEMP_BRANCH"
git branch -D "$TEMP_BRANCH" 2>/dev/null # Delete if exists
git checkout -b "$TEMP_BRANCH" || { print_error "Failed to create temporary branch"; exit 1; }

TOTAL_COMMITS=$(git rev-list --count HEAD)
print_status "Total commits in repository: $TOTAL_COMMITS"

print_status "Getting list of commits..."
COMMIT_LIST=$(git rev-list --reverse HEAD)
COMMIT_ARRAY=($COMMIT_LIST)

NUM_CHUNKS=$(( (TOTAL_COMMITS + CHUNK_SIZE - 1) / CHUNK_SIZE ))
print_status "Will push in approximately $NUM_CHUNKS chunks of up to $CHUNK_SIZE commits each"

read -p "Ready to begin chunked push? (y/n) " -n 1 -r
echo
if [[ ! $REPLY =~ ^[Yy]$ ]]; then
    print_error "Aborting chunked push"
    git checkout "$SOURCE_BRANCH"
    git branch -D "$TEMP_BRANCH"
    exit 1
fi

push_chunk_with_retry() {
    local chunk_commit=$1
    local chunk_num=$2
    local start_idx=$3
    local end_idx=$4
    
    git reset --hard "$chunk_commit" || { print_error "Failed to reset to commit $chunk_commit"; return 1; }
    
    while true; do
        print_status "Pushing chunk $chunk_num/$NUM_CHUNKS to remote..."
        if git push -f "$REMOTE_URL" "$TEMP_BRANCH:$TARGET_BRANCH"; then
            print_status "Successfully pushed chunk $chunk_num/$NUM_CHUNKS"
            return 0
        else
            print_error "Failed to push chunk $chunk_num/$NUM_CHUNKS"
            print_warning "Connection issue or remote error occurred"
            print_warning "Current position: commits $start_idx to $end_idx of $TOTAL_COMMITS"
            
            read -p "Retry this chunk? (y/n) " -n 1 -r
            echo
            if [[ ! $REPLY =~ ^[Yy]$ ]]; then
                print_error "Aborting chunk push at user request"
                return 1
            fi
            print_status "Retrying chunk $chunk_num/$NUM_CHUNKS..."
            sleep 2
        fi
    done
}

CURRENT_CHUNK=1
i=0
while [ $i -lt $TOTAL_COMMITS ]; do
    END_IDX=$((i + CHUNK_SIZE - 1))
    if [ $END_IDX -ge $TOTAL_COMMITS ]; then
        END_IDX=$((TOTAL_COMMITS - 1))
    fi
    
    CHUNK_COMMIT="${COMMIT_ARRAY[$END_IDX]}"
    
    print_status "Processing chunk $CURRENT_CHUNK/$NUM_CHUNKS (commits $i to $END_IDX)"
    
    if push_chunk_with_retry "$CHUNK_COMMIT" "$CURRENT_CHUNK" "$i" "$END_IDX"; then
        i=$((i + CHUNK_SIZE))
        CURRENT_CHUNK=$((CURRENT_CHUNK + 1))
    else
        print_warning "Failed to push chunk $CURRENT_CHUNK after retries"
        
        read -p "Try with half the chunk size? (y/n) " -n 1 -r
        echo
        if [[ $REPLY =~ ^[Yy]$ ]]; then
            CHUNK_SIZE=$((CHUNK_SIZE / 2))
            print_status "Adjusted chunk size to $CHUNK_SIZE"
            NUM_CHUNKS=$(( (TOTAL_COMMITS - i + CHUNK_SIZE - 1) / CHUNK_SIZE + CURRENT_CHUNK - 1 ))
            print_status "Will now push in approximately $NUM_CHUNKS total chunks"
        else
            print_error "Aborting chunked push at chunk $CURRENT_CHUNK"
            break
        fi
    fi
done

print_status "Returning to original branch: $SOURCE_BRANCH"
git checkout "$SOURCE_BRANCH" || { print_warning "Failed to checkout original branch"; }
git branch -D "$TEMP_BRANCH" || { print_warning "Failed to delete temporary branch"; }

if [ $i -ge $TOTAL_COMMITS ]; then
    print_status "Successfully pushed all chunks to $REMOTE_URL:$TARGET_BRANCH"
else
    print_warning "Push operation did not complete all chunks"
    print_warning "Pushed approximately $((i / CHUNK_SIZE)) chunks out of $NUM_CHUNKS"
    print_warning "Last successful commit was around commit $i of $TOTAL_COMMITS"
fi