#!/bin/bash

# Configuration
USER_FILE="${HOME:?HOME not set}/.qtx_branch_last_user"
VALID_TYPES=("feature" "hotfix" "refactor" "improvement" "doc" "fix")

# Trap for clean Ctrl+C handling
trap 'echo ""; echo "Cancelled."; exit 130' INT TERM

# Check dependencies
if ! command -v git &> /dev/null; then
    echo "Error: 'git' command not found" >&2
    exit 1
fi

# Check we're in project root
if [[ ! -f "Makefile" ]]; then
    echo "Error: Makefile not found. Run this script from project root." >&2
    exit 1
fi

echo "=== Make Branch Helper ==="
echo ""

# Load last user safely using shell built-in
LAST_USER=""
if [[ -f "$USER_FILE" && -r "$USER_FILE" && ! -L "$USER_FILE" ]]; then
    # Use shell built-in instead of cat, only read first line
    LAST_USER=$(head -n 1 "$USER_FILE" 2>/dev/null || true)
fi

if [[ -n "$LAST_USER" ]]; then
    echo "Last user found: $LAST_USER"
fi

# Select branch type
echo ""
echo "Select branch type:"
select TYPE in "${VALID_TYPES[@]}"; do
    if [[ -n "$TYPE" ]]; then
        echo "Selected type: $TYPE"
        break
    else
        echo "Invalid selection. Please try again."
    fi
done

# Get user with validation
echo ""
while true; do
    read -r -p "Enter user (alphanumeric, _, or -) [${LAST_USER:-none}]: " USER
    USER="${USER:-$LAST_USER}"

    if [[ -z "$USER" ]]; then
        echo "Error: user is required (e.g., jdoe, fsmith)" >&2
        continue
    fi

    if [[ ! "$USER" =~ ^[a-zA-Z0-9_-]+$ ]]; then
        echo "Error: user must be alphanumeric with optional _ or - (e.g., jdoe, f_smith)" >&2
        continue
    fi

    break
done

# Save user preference securely with umask
if [[ -n "$HOME" ]]; then
    # Remove if it's a symlink (prevent symlink attacks)
    [[ -L "$USER_FILE" ]] && rm -f "$USER_FILE"

    # Create with restricted permissions (600)
    (umask 077 && echo "$USER" > "$USER_FILE")
fi

# Get issue number with numeric validation
echo ""
while true; do
    read -r -p "Enter issue number (numeric only): " ISSUE

    if [[ -z "$ISSUE" ]]; then
        echo "Error: issue number is required (e.g., 123, 456)" >&2
        continue
    fi

    if [[ ! "$ISSUE" =~ ^[0-9]+$ ]]; then
        echo "Error: issue number must be numeric only (e.g., 39, 123)" >&2
        continue
    fi

    break
done

# Get summary with validation
echo ""
while true; do
    read -r -p "Enter summary (max 100 chars): " SUMMARY

    # Trim leading/trailing whitespace
    SUMMARY=$(echo "$SUMMARY" | xargs)

    if [[ -z "$SUMMARY" ]]; then
        echo "Error: summary is required (e.g., 'add new endpoint', 'fix login bug')" >&2
        continue
    fi

    if [[ ${#SUMMARY} -gt 100 ]]; then
        echo "Error: summary too long (${#SUMMARY} chars, max 100)" >&2
        continue
    fi

    # Basic validation - allow common characters
    if [[ ! "$SUMMARY" =~ ^[a-zA-Z0-9\ _\-]+$ ]]; then
        echo "Warning: summary contains special characters. Use only letters, numbers, spaces, hyphens, and underscores." >&2
        read -r -p "Continue anyway? (y/N): " CONFIRM
        if [[ ! "$CONFIRM" =~ ^[Yy]$ ]]; then
            continue
        fi
    fi

    break
done

# Get ISSUE_PREFIX from Makefile.common (default to SKL if not found)
ISSUE_PREFIX="SKL"
if [[ -f "Makefile.common" ]]; then
    # Extract ISSUE_PREFIX from Makefile.common
    PREFIX_LINE=$(grep "^ISSUE_PREFIX" Makefile.common 2>/dev/null || true)
    if [[ -n "$PREFIX_LINE" ]]; then
        ISSUE_PREFIX=$(echo "$PREFIX_LINE" | cut -d'=' -f2 | tr -d ' ')
    fi
fi

# Build branch name: type/user/PREFIX-number/summary_with_underscores
BRANCH_NAME="$TYPE/$USER/$ISSUE_PREFIX-$ISSUE/${SUMMARY// /_}"

# Show summary and execute
echo ""
echo "Creating branch:"
echo "  Type:    $TYPE"
echo "  User:    $USER"
echo "  Issue:   $ISSUE_PREFIX-$ISSUE"
echo "  Summary: $SUMMARY"
echo "  Branch:  $BRANCH_NAME"
echo ""

# Create the git branch
if git checkout -b "$BRANCH_NAME"; then
    echo ""
    echo "✓ Branch '$BRANCH_NAME' created and checked out successfully"
    exit 0
else
    echo "" >&2
    echo "✗ Failed to create branch '$BRANCH_NAME'" >&2
    exit 1
fi