#!/bin/bash
# ------------------------------------------------------------------
# Author: ChatGPT
# Generated on: $(date '+%Y-%m-%d')
#
# This script recursively creates or updates a table-of-contents README
# file in each non-hidden directory. The file is named "Folder Name - README.md".
#
# Each README includes:
#   - An author/date header.
#   - A header with the folder's name.
#   - An alphabetically sorted list of immediate subdirectories, with links
#     to that subdirectory’s own README.
#   - An alphabetically sorted list of immediate files (excluding the generated README).
#   - A "Summary" section with a short description generated by an LLM (using llama3.2:latest).
#
# Hidden directories (or any directory under a hidden parent such as .git) are skipped.
#
# The script only updates a README if the static content (header, subdirectories and files)
# changes. The LLM summary output is excluded from the diff check.
#
# Progress is printed as "[x/y] Updated: {dir}" or "[x/y] No change: {dir}".
# ------------------------------------------------------------------

# Set the base directory (change "." if necessary)
base_dir="."

# Build an array of directories to process.
dirs=()
while IFS= read -r -d '' dir; do
    # Skip directories that are hidden or inside a hidden parent (like .git)
    if [[ "$(basename "$dir")" == .* ]] || [[ "$dir" == *"/.git"* ]]; then
        continue
    fi
    dirs+=( "$dir" )
done < <(find "$base_dir" -type d -print0)

total=${#dirs[@]}
count=0

for dir in "${dirs[@]}"; do
    count=$((count+1))
    
    # For the top-level directory, use the actual name from $PWD; otherwise, use the directory's basename.
    if [ "$dir" = "$base_dir" ]; then
        base=$(basename "$PWD")
    else
        base=$(basename "$dir")
    fi

    # Define the path for the README file: "Folder Name - README.md"
    readme="$dir/${base} - README.md"

    # Create a temporary file to hold the new static content.
    tmp_static=$(mktemp)
    {
      echo "Generated by ChatGPT on $(date '+%Y-%m-%d')"
      echo ""
      echo "# Table of Contents for ${base}"
      echo ""
    } > "$tmp_static"

    #########################
    # Process Subdirectories
    #########################
    subdirs=()
    while IFS= read -r -d '' subdir; do
        sub_basename=$(basename "$subdir")
        if [ -n "$sub_basename" ]; then
            subdirs+=( "$sub_basename" )
        fi
    done < <(find "$dir" -mindepth 1 -maxdepth 1 -type d ! -name '.*' -print0)
    
    if [ ${#subdirs[@]} -gt 0 ]; then
        mapfile -t sorted_subdirs < <(printf "%s\n" "${subdirs[@]}" | sort)
        echo "## Subdirectories" >> "$tmp_static"
        for sub in "${sorted_subdirs[@]}"; do
            # Link format: [[Subfolder/Subfolder - README]]
            line="- [[${sub}/${sub} - README]]"
            printf "%s\n" "$line" >> "$tmp_static"
        done
        echo "" >> "$tmp_static"
    fi

    #################
    # Process Files
    #################
    files=()
    while IFS= read -r -d '' file; do
        fbase=$(basename "$file")
        if [ -n "$fbase" ]; then
            files+=( "$fbase" )
        fi
    done < <(find "$dir" -mindepth 1 -maxdepth 1 -type f ! -path "$readme" -print0)
    
    if [ ${#files[@]} -gt 0 ]; then
        mapfile -t sorted_files < <(printf "%s\n" "${files[@]}" | sort)
        echo "## Files" >> "$tmp_static"
        for f in "${sorted_files[@]}"; do
            line="- [[${f}]]"
            printf "%s\n" "$line" >> "$tmp_static"
        done
        echo "" >> "$tmp_static"
    fi

    # Determine if the static content has changed.
    static_changed=1
    if [ -f "$readme" ]; then
        # Extract the static portion from the existing README (everything before "## Summary")
        existing_static=$(sed '/^## Summary/ q' "$readme")
        new_static=$(cat "$tmp_static")
        if [ "$existing_static" = "$new_static" ]; then
            static_changed=0
        fi
    fi

    if [ $static_changed -eq 0 ]; then
        echo "[$count/$total] No change: $dir"
        rm "$tmp_static"
        continue
    fi

    #################
    # Query LLM for Summary
    #################
    prompt="Based on the following table of contents, provide a short summary description of what this directory is about:
$(cat "$tmp_static")"
    # Query the model using the Ollama CLI with the llama3.2:latest model.
    summary=$(ollama run llama3.2 "$prompt")
    
    # Build the full new content: static portion + summary section.
    {
      cat "$tmp_static"
      echo "## Summary"
      echo "$summary"
      echo ""
    } > "$readme"

    rm "$tmp_static"
    echo "[$count/$total] Updated: $dir"
done