#!/bin/bash

# Git Configuration Automation Script with Directory Management
# -------------------------------------------------------------
# This enhanced script automates the process of applying Git configurations
# based on the current working directory, ensuring all repositories for a specific
# client use the correct Git user name and email settings. It is essential for maintaining
# consistent commit metadata across projects and minimizing the risk of commits being
# attributed to the wrong user. Additionally, it now includes functionality to detect
# when a project (repository) is deleted from or re-added to the client's directory,
# updating the configuration accordingly.
#
# How It Works:
# The script reads a JSON configuration file (`git-configs.json`) that contains mappings
# between directory paths and the corresponding Git configurations (user name and email),
# along with a list of subdirectories (`subDirs`) under each path. When executed, it
# checks the current directory against the configured paths and applies the matching Git
# configuration if found. If a repository is deleted or re-added, the script updates
# `subDirs` to reflect these changes, ensuring the Git configuration is accurate and current.
#
# JSON Configuration File Structure:
# The configuration file should be structured as follows, with each key being a path
# to a client's main directory, and each value being an object with `email`, `name`,
# and `subDirs` properties for Git configuration and directory tracking.
#
# Example:
# {
#   "/Users/username/Projects/ClientA": {
#     "email": "clienta@example.com",
#     "name": "Client A",
#     "subDirs": ["/Users/username/Projects/ClientA/Repo1", "/Users/username/Projects/ClientA/Repo2"]
#   },
#   "/Users/username/Projects/ClientB": {
#     "email": "clientb@example.com",
#     "name": "Client B",
#     "subDirs": ["/Users/username/Projects/ClientB/Repo1"]
#   }
# }
#
# Setup Instructions for Zsh Users:
# 1. Place the `git-configs.json` file in a directory accessible by this script.
# 2. Ensure this script is executable by running `chmod +x this_script_name.sh`.
# 3. To execute this script automatically in Zsh, open your `.zshrc` file in a text editor,
#    add a line to source this script when a new shell session starts, and use the `chpwd`
#    hook to execute this script after each directory change. Save the changes to `.zshrc`
#    and apply them by running `source ~/.zshrc` or by opening a new terminal window.
#
# Usage:
# Navigate to a project directory in your terminal, and the script will automatically apply
# the appropriate Git configuration based on the current directory's match in the
# `git-configs.json` file. It will also update the configuration if projects are deleted
# or re-added to the client's directory, ensuring accurate and up-to-date Git settings.
#
# Note: This script requires `jq` for JSON parsing. Ensure it is installed and available in
# your PATH.
#
# Following these setup and usage guidelines, teams can streamline their Git workflow,
# ensuring all commits are correctly attributed and consistent across projects for each client,
# and dynamically manage project directories within each client's configuration.

# Workflow Diagram:
# +----------------------------------+        +-------------------+        +---------------------+       +------------------------+
# | Manually add the folder and      |        | Verify if the     |  No    | Read the JSON       |       | Iterate over each      |
# | configuration in                 +------->+ current directory +------->+ configuration file  +------>+ configured directory   |
# | git-configs.json                 |        | is a Git repo     |        | (git-configs.json)  |       | in the JSON            |
# +----------------------------------+        +--------+----------+        +---------------------+       +------------+-----------+
#                                                   |                                                            |
#                                                  Yes                                                           |
#                                                   |                                                            |
#                                                   v                                                            v
#                                             +-----+------+       Configuration not exists /     +-------------------------+       +--------------------------------+
#                                             | End script |       already applied for this dir   | Apply Git configuration |       | Update JSON file with the      |
#                                             | execution  |<------------------------------------ + (name, email) and       +------>+ current directory added to     |
#                                             +------------+                                      | update `subDirs`        |       | `subDirs`                      |
#                                                                                                 +-------------------------+       +--------------------------------+


# Path to the JSON configuration file, located in the same directory as this script
CONFIG_FILE="$HOME/.config/git-configs.json"

# This script dynamically applies Git configurations based on the current directory.
# It reads settings from a JSON file, located in the same directory as the script.
# The JSON file contains key-value pairs where each key is a path to a directory
# (or parent directory of multiple repositories), and the value is an object
# containing 'email' and 'name' for Git configuration.

# JSON File Structure Example:
# {
#   "/Users/username/Projects/ClientA": {
#     "email": "clienta@example.com",
#     "name": "Client A",
#     "subDirs": ["/Users/username/Projects/ClientA/Repo1", "/Users/username/Projects/ClientA/Repo2"]
#   },
#   "/Users/username/Projects/ClientB": {
#     "email": "clientb@example.com",
#     "name": "Client B",
#     "subDirs": ["/Users/username/Projects/ClientB/Repo1"]
#   }
# }
# Each key in the JSON file represents a directory path for which the specified
# Git configuration (email and name) should be applied. This allows for different
# Git configurations to be automatically applied based on the current working directory.

# Function to apply Git configuration
apply_git_config() {
  local config_email=$(jq -r ".[\"$1\"].email" "$CONFIG_FILE")
  local config_name=$(jq -r ".[\"$1\"].name" "$CONFIG_FILE")
  local config_subdirs=$(jq -r ".[\"$1\"].subDirs[]" "$CONFIG_FILE")

  # Check if configuration exists for the path and has not been applied yet
  if [ "$config_email" != "null" ] && [ "$config_name" != "null" ] && [[ ! " $config_subdirs " =~ " $CURRENT_DIR " ]]; then
    git config user.email "$config_email"
    git config user.name "$config_name"
    
    # Update the 'subDirs' array in the JSON file
    jq --arg dir "$1" --arg subdir "$CURRENT_DIR" 'if .[$dir].subDirs == null then .[$dir].subDirs = [$subdir] else if (.[$dir].subDirs | index($subdir)) == null then .[$dir].subDirs += [$subdir] else . end end' "$CONFIG_FILE" > temp.$$ && mv temp.$$ "$CONFIG_FILE"
  fi
}

# Check if the current directory is a Git repository
if git rev-parse --is-inside-work-tree > /dev/null 2>&1; then
  # Iterate through the directories defined in the JSON file and apply configuration if the current directory matches or is a subdirectory
  CURRENT_DIR=$(pwd)
  for KEY in $(jq -r 'keys[]' "$CONFIG_FILE"); do
    if [[ "$CURRENT_DIR" == "$KEY"* ]]; then
      apply_git_config "$KEY"
      break
    fi
  done
fi