review

#!/bin/bash
# Review git diffs by sending them to Claude Code for analysis
# Usage: review [options] <branch1> [branch2]
#        review --pr <number>

set -e

show_help() {
    cat << 'EOF'
Usage: review [options] <branch1> [branch2]
       review --pr <number>

Review git diffs by sending them to Claude Code for analysis.

Modes:
  review branch1 branch2    Show changes from branch1 to branch2
  review branch1             Show changes from branch1 to current branch
  review --pr 123            Review GitHub PR #123

The script collects:
  - The diff between branches
  - List of all changed files

This context is formatted and piped to Claude Code for review.
Claude Code will read any files it needs for additional context.

Examples:
  review main feature-branch
  review develop
  review --pr 456

Options:
  --pr <number>     Review a specific GitHub PR (requires gh CLI)
  --help, -h, help  Show this help message
EOF
}

# Check for help flag
if [[ "$1" == "help" || "$1" == "--help" || "$1" == "-h" ]]; then
    show_help
    exit 0
fi

# Validate we're in a git repository
if ! git rev-parse --is-inside-work-tree > /dev/null 2>&1; then
    echo "Error: Not inside a Git repository." >&2
    exit 1
fi

# List all changed files
list_changed_files() {
    local branch1="$1"
    local branch2="$2"

    git diff --name-status "$branch1..$branch2" 2>/dev/null || echo "No files changed"
}

# Generate the review output
generate_review_output() {
    local branch1="$1"
    local branch2="$2"
    local diff_output
    local changed_files

    diff_output=$(git diff "$branch1..$branch2" 2>/dev/null || echo "No diff available")
    changed_files=$(list_changed_files "$branch1" "$branch2")

    cat << EOF
=== PROMPT ===
Review these code changes

=== DIFF ===
$diff_output

=== CHANGED FILES ===
$changed_files
EOF
}

# Parse arguments and determine mode
if [[ "$1" == "--pr" ]]; then
    # PR mode
    pr_number="${2:?Error: PR number required. Usage: review --pr <number>}"

    # Validate PR number is numeric
    if ! [[ "$pr_number" =~ ^[0-9]+$ ]]; then
        echo "Error: PR number must be numeric: $pr_number" >&2
        exit 1
    fi

    # Check if gh CLI is installed
    if ! command -v gh >/dev/null 2>&1; then
        echo "Error: 'gh' CLI not found. Install it from https://cli.github.com" >&2
        exit 1
    fi

    # Validate PR exists
    if ! gh pr view "$pr_number" >/dev/null 2>&1; then
        echo "Error: PR #$pr_number not found or not accessible" >&2
        exit 1
    fi

    # Get PR branch information
    pr_branch=$(gh pr view "$pr_number" --json headRefName -q .headRefName)
    base_branch=$(gh pr view "$pr_number" --json baseRefName -q .baseRefName)

    # Fetch PR branch if not local
    git fetch origin "$pr_branch:$pr_branch" 2>/dev/null || true

    echo "Reviewing PR #$pr_number: $pr_branch -> $base_branch"
    generate_review_output "$base_branch" "$pr_branch" | claude code

elif [ $# -eq 2 ]; then
    # Two branch mode
    branch1="$1"
    branch2="$2"

    # Validate branches exist
    if ! git rev-parse --verify "$branch1" >/dev/null 2>&1; then
        echo "Error: Branch '$branch1' does not exist" >&2
        exit 1
    fi

    if ! git rev-parse --verify "$branch2" >/dev/null 2>&1; then
        echo "Error: Branch '$branch2' does not exist" >&2
        exit 1
    fi

    echo "Reviewing changes from $branch1 to $branch2"
    generate_review_output "$branch1" "$branch2" | claude code

elif [ $# -eq 1 ]; then
    # One branch mode - compare provided branch to current HEAD
    branch1="$1"
    branch2="HEAD"

    # Validate branch exists
    if ! git rev-parse --verify "$branch1" >/dev/null 2>&1; then
        echo "Error: Branch '$branch1' does not exist" >&2
        exit 1
    fi

    echo "Reviewing changes from $branch1 to current branch"
    generate_review_output "$branch1" "$branch2" | claude code

else
    # Invalid arguments
    echo "Error: Invalid arguments" >&2
    echo "" >&2
    show_help
    exit 1
fi