#!/bin/bash
set -euo pipefail

# Color definitions
BOLD='\033[1m'
RED='\033[31m'
BLUE='\033[34m'
GREEN='\033[32m'
YELLOW='\033[33m'
RESET='\033[0m'

if [[ $# -ne 1 ]]; then
    echo -e "${BOLD}${RED}Error${RESET}${RED}: No commit hash provided.${RESET}"
    echo "Usage: $0 <commit-hash>"
    exit 1
fi

COMMIT="$1"
START_BRANCH="$(git branch --show-current)"

if [[ -z "$START_BRANCH" ]]; then
    echo -e "${BOLD}${RED}Error${RESET}${RED}: Detached HEAD is not supported.${RESET}"
    exit 1
fi

if ! git rev-parse --verify --quiet "${COMMIT}^{commit}" >/dev/null; then
    echo -e "${BOLD}${RED}Error${RESET}${RED}: Commit '$COMMIT' not found.${RESET}"
    exit 1
fi

COMMIT="$(git rev-parse --short "$COMMIT")"
COMMIT_MSG="$(git log -1 --pretty=format:%s "$COMMIT")"
PARENT_COUNT="$(git rev-list --parents -n 1 "$COMMIT" | wc -w | tr -d ' ')"

if [[ "$PARENT_COUNT" -gt 2 ]]; then
    echo -e "${BOLD}${RED}Error${RESET}${RED}: Merge commits are not supported.${RESET}"
    exit 1
fi

if [[ -n "$(git status --porcelain)" ]]; then
    echo -e "${BOLD}${RED}Error${RESET}${RED}: Working tree is not clean.${RESET}"
    echo "Commit, stash, or discard local changes before replicating a commit."
    exit 1
fi

restore_branch() {
    git switch --quiet "$START_BRANCH"
}

handle_error() {
    echo -e "${BOLD}${RED}Error${RESET}${RED}: Replication failed on branch '$(git branch --show-current)'.${RESET}"

    if [[ -f "$(git rev-parse --git-path CHERRY_PICK_HEAD 2>/dev/null || true)" ]]; then
        git cherry-pick --abort >/dev/null 2>&1 || true
    fi

    restore_branch
    exit 1
}

trap handle_error ERR

echo -e "${BLUE}Propagating commit ${BOLD}'${COMMIT}: ${COMMIT_MSG}'${RESET}${BLUE} from '${START_BRANCH}' to local branches.${RESET}"

while IFS= read -r BRANCH; do
    if [[ "$BRANCH" == "$START_BRANCH" ]]; then
        continue
    fi

    git switch --quiet "$BRANCH"

    if git merge-base --is-ancestor "$COMMIT" HEAD; then
        echo -e "${YELLOW}Skipping ${BRANCH}: commit is already present.${RESET}"
        continue
    fi

    echo -e "${BLUE}Cherry-picking ${COMMIT} onto ${BRANCH}.${RESET}"
    if ! git cherry-pick "$COMMIT"; then
        if git diff --quiet && git diff --cached --quiet; then
            echo -e "${YELLOW}Skipping ${BRANCH}: commit is already applied as an equivalent patch.${RESET}"
            git cherry-pick --skip
            continue
        fi

        false
    fi

    echo -e "${GREEN}Commit successfully cherry-picked to ${BRANCH}.${RESET}"
    git push
    echo -e "${GREEN}Branch ${BRANCH} successfully pushed.${RESET}"

done < <(git for-each-ref --format='%(refname:short)' refs/heads)

restore_branch

echo -e "${GREEN}Done. Returned to '${START_BRANCH}'.${RESET}"