gitin

#!/usr/bin/env bash

# This script automates git add, commit, and push by generating commit messages
# using the Gemini API from Google Cloud's Generative AI models.
# you will need to create ~/.env file with GEMINI_API_KEY variable set.


# Configuration 
# Stop the script if any command fails
set -e

# Check for Dependencies 
if ! command -v jq &> /dev/null; then
    echo "Error: 'jq' is not installed." >&2
    echo "Please install it to parse the API response (e.g., 'brew install jq' or 'apt install jq')." >&2
    exit 1
fi

if ! command -v curl &> /dev/null; then
    echo "Error: 'curl' is not installed." >&2
    echo "Please install it to make the API call (e.g., 'apt install curl')." >&2
    exit 1
fi

if ! command -v git &> /dev/null; then
    echo "Error: 'git' is not installed." >&2
    echo "Please install it to manage git repositories (e.g., 'apt install git')." >&2
    exit 1
fi

# Load API Key
ENV_FILE="$HOME/.env"

if [ ! -f "$ENV_FILE" ]; then
    echo "Error: API key file not found at $ENV_FILE" >&2
    exit 1
fi

# Load the .env file
export $(grep -v '^#' "$ENV_FILE" | xargs)

if [ -z "$GEMINI_API_KEY" ]; then
    echo "Error: GEMINI_API_KEY is not set in $ENV_FILE" >&2
    exit 1
fi

# Check if there are any changes at all
if [ -z "$(git status --porcelain)" ]; then
    echo "No changes to commit. Exiting."
    exit 0
fi

# Find Latest "Pro" Model
echo "Fetching latest model to use..."
LIST_MODELS_URL="https://generativelanguage.googleapis.com/v1beta/models?key=${GEMINI_API_KEY}"

# Make the API call to list models
MODEL_RESPONSE=$(curl -s -X GET "$LIST_MODELS_URL")

# Parse the response to find the latest "pro" model that supports generateContent
MODEL_NAME=$(echo "$MODEL_RESPONSE" | jq -r '
    .models |
    map(
        select(
            (.name | (contains("pro") and (contains("flash") | not))) and
            (.supportedGenerationMethods | index("generateContent"))
        )
    ) |
    map(.name) |
    sort |
    reverse |
    .[0]
')

# Check if we successfully found a model
if [ -z "$MODEL_NAME" ] || [ "$MODEL_NAME" == "null" ]; then
    echo "Error: Could not find a suitable 'pro' model." >&2
    echo "API Response: $MODEL_RESPONSE" >&2
    exit 1
fi


# Run Git add
echo "Changes detected. Running 'git add .'..."
git add .

# Get the diff of *staged* files
DIFF_OUTPUT=$(git diff --staged)

# Check if `git add` actually staged anything (it might not, e.g., if all changes are .gitignored)
if [ -z "$DIFF_OUTPUT" ]; then
    echo "No staged changes to commit. Exiting."
    exit 0
fi

echo "Staged changes detected. Generating commit message..."

# Prepare Gemini API Payload

# Define the prompt as a shell variable
PROMPT_TEXT="As a senior code developer, analyze the following git diff. Create a single, concise commit message in the imperative mood (e.g., 'Fix bug' not 'Fixed bug'). The message must be under 72 characters. Focus on the *what* and *why* of the change. Do not include file names or any prefix like 'Commit:'.

Diff:
---
"

# Use jq --arg to safely pass the prompt and diff variables
JSON_PAYLOAD=$(jq -n \
                  --arg prompt "$PROMPT_TEXT" \
                  --arg diff "$DIFF_OUTPUT" \
                  '{
                    "contents": [
                      {
                        "parts": [
                          {"text": $prompt},
                          {"text": $diff}
                        ]
                      }
                    ],
                    "generationConfig": {
                      "temperature": 0.3
                    }
                  }')

# Call Gemini API
# Construct the API URL using the dynamically found MODEL_NAME
API_URL="https://generativelanguage.googleapis.com/v1beta/${MODEL_NAME}:generateContent?key=${GEMINI_API_KEY}"

API_RESPONSE=$(curl -s -X POST \
     -H "Content-Type: application/json" \
     -d "$JSON_PAYLOAD" \
     "$API_URL")

# Parse Response and Commit 
# Parse the text from the response, remove surrounding quotes, and trim whitespace
COMMIT_MSG=$(echo "$API_RESPONSE" | jq -r '.candidates[0].content.parts[0].text' | sed -e 's/^[ \t"]*//' -e 's/[ \t"]*$//')

# Handle API errors (e.g., if 'candidates' is null or text is empty)
if [ -z "$COMMIT_MSG" ] || [ "$COMMIT_MSG" == "null" ]; then
    echo "Error: Failed to generate commit message from Gemini." >&2
    # ShellCheck (SC2086) Fix: Quote the variable
    echo "API Response: $API_RESPONSE" >&2
    exit 1
fi

echo "---"
echo "Generated Commit: $COMMIT_MSG"
echo "---"

# --- 8. Git Commit and Push ---
echo "Committing..."
git commit -m "$COMMIT_MSG"

echo "Pushing to remote..."
git push

echo "✅ Changes committed and pushed successfully."