#!/usr/bin/env bash
# Pre-startup Validator Prerequisites Check
# Validates all required files and configurations before starting Besu

set -euo pipefail

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

log_error() { echo -e "${RED}[ERROR]${NC} $1" >&2; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $1"; }
log_info() { echo -e "${GREEN}[INFO]${NC} $1"; }

check_file() {
    local file=$1
    local description=$2
    
    if [ -f "$file" ]; then
        log_info "$description: OK ($file)"
        return 0
    else
        log_error "$description: MISSING ($file)"
        return 1
    fi
}

fix_missing_file() {
    local file=$1
    local description=$2
    local fallback=$3
    
    if [ ! -f "$file" ]; then
        log_warn "Fixing missing $description..."
        
        if [ -f "$fallback" ]; then
            mkdir -p "$(dirname "$file")"
            ln -sf "$fallback" "$file"
            log_info "Created symlink: $file -> $fallback"
        else
            log_error "Cannot fix: $description missing and no fallback"
            return 1
        fi
    fi
}

main() {
    local errors=0
    
    # Check genesis file
    if ! check_file "/genesis/genesis.json" "Genesis file"; then
        fix_missing_file "/genesis/genesis.json" "genesis file" "/etc/besu/genesis.json" || ((errors++))
    fi
    
    # Check static-nodes file
    if ! check_file "/genesis/static-nodes.json" "Static nodes file"; then
        fix_missing_file "/genesis/static-nodes.json" "static-nodes file" "/etc/besu/static-nodes.json" || {
            # Create empty file if no fallback
            mkdir -p /genesis
            echo "[]" > /genesis/static-nodes.json
            log_info "Created empty static-nodes.json"
        }
    fi
    
    # Check permissions file
    if ! check_file "/permissions/permissions-accounts.toml" "Permissions file"; then
        fix_missing_file "/permissions/permissions-accounts.toml" "permissions file" "/etc/besu/permissions-accounts.toml" || {
            # Create proper empty file
            mkdir -p /permissions
            cat > /permissions/permissions-accounts.toml <<EOF
# Permissions Accounts Configuration
# Empty allowlist - all accounts allowed
accounts-allowlist=[]
EOF
            log_info "Created empty permissions-accounts.toml"
        }
    fi
    
    # Validate TOML format
    if [ -f "/permissions/permissions-accounts.toml" ]; then
        if ! grep -q "accounts-allowlist" /permissions/permissions-accounts.toml; then
            log_warn "Fixing invalid permissions file format..."
            cat > /permissions/permissions-accounts.toml <<EOF
# Permissions Accounts Configuration
# Empty allowlist - all accounts allowed
accounts-allowlist=[]
EOF
            log_info "Fixed permissions file format"
        fi
    fi
    
    if [ "$errors" -gt 0 ]; then
        log_error "Prerequisites check failed with $errors error(s)"
        exit 1
    fi
    
    log_info "All prerequisites satisfied"
    exit 0
}

main "$@"