#!/bin/bash

# Function to escape special characters for Mermaid
escape_for_mermaid() {
    echo "$1" | sed 's/[^a-zA-Z0-9]/_/g'
}

# Output file
output_file="branches_diagram.mmd"

# Start the Mermaid diagram
{
echo "%%{init: { 'theme': 'base' } }%%"
echo "gitGraph"

# Set master as the main branch
main_branch="master"

# Start with the main branch
echo "    commit id: \"Initial commit\""
echo "    branch $main_branch"
echo "    checkout $main_branch"

# Keep track of declared branches
declared_branches=("$main_branch")

# Function to check if a branch is declared
is_branch_declared() {
    local branch=$1
    for declared_branch in "${declared_branches[@]}"; do
        if [[ "$declared_branch" == "$branch" ]]; then
            return 0
        fi
    done
    return 1
}

# Function to find the base branch
find_base_branch() {
    local branch=$1
    local base=$(git merge-base --fork-point "$branch" "$main_branch" || echo "$main_branch")
    if [[ -z "$base" ]]; then
        echo "$main_branch"
    else
        echo "$base"
    fi
}

# Function to declare a branch if not already declared
declare_branch() {
    local branch=$1
    if ! is_branch_declared "$branch"; then
        echo "    branch $(escape_for_mermaid "$branch")"
        declared_branches+=("$branch")
    fi
}

# Function to recursively process merged branches
process_merged_branches() {
    local branch=$1
    local merged_branches=$(git branch --merged "$branch" | grep -v "\* $branch" | grep -v "$main_branch")
    if [ -n "$merged_branches" ]; then
        for merged_branch in $merged_branches; do
            declare_branch "$merged_branch"
            echo "    checkout $(escape_for_mermaid "$branch")"
            echo "    merge $(escape_for_mermaid "$merged_branch")"
            process_merged_branches "$merged_branch"
        done
    fi
}

# Process each branch
for branch in $(git for-each-ref --sort=committerdate --format='%(refname:short)' refs/heads/); do
    base_branch=$(find_base_branch "$branch")
    declare_branch "$branch"
    echo "    checkout $(escape_for_mermaid "$branch")"
    echo "    commit id: \"$(git log -1 --pretty=format:%s "$branch")\""
    process_merged_branches "$branch"
done

# Check for branches not yet merged into master
not_merged=$(git branch --no-merged "$main_branch")
if [ -n "$not_merged" ]; then
    echo "    commit id: \"Branches not yet merged into master:\""
    for branch in $not_merged; do
        echo "    commit id: \"$branch\" - merged into: $(git branch --merged "$branch" | grep -v "\* $branch" | grep -v "$main_branch" | tr '\n' ' ')"
    done
fi

} > $output_file

echo "Mermaid diagram saved to $output_file"