#!/bin/bash

# Environment validation script
# Validates all .env files for consistency and completeness

set -e

print_header() {
    echo "🔍 Environment Configuration Validation"
    echo "======================================"
    echo ""
}

print_section() {
    echo ""
    echo "📋 $1"
    echo "$(printf '%*s' ${#1} '' | tr ' ' '-')"
}

print_success() {
    echo "✅ $1"
}

print_warning() {
    echo "⚠️  $1"
}

print_error() {
    echo "❌ $1"
}

# Required variables for each environment
CORE_VARS=(
    "COUCHDB_USER"
    "COUCHDB_PASSWORD"
    "VITE_COUCHDB_URL"
    "VITE_COUCHDB_USER"
    "VITE_COUCHDB_PASSWORD"
    "APP_BASE_URL"
    "MAILGUN_API_KEY"
    "MAILGUN_DOMAIN"
    "MAILGUN_FROM_EMAIL"
)

K8S_VARS=(
    "INGRESS_HOST"
)

OPTIONAL_VARS=(
    "NODE_ENV"
    "VITE_GOOGLE_CLIENT_ID"
    "VITE_GITHUB_CLIENT_ID"
)

validate_file() {
    local file="$1"
    local file_type="$2"

    print_section "Validating $file ($file_type)"

    if [[ ! -f "$file" ]]; then
        print_error "File not found: $file"
        return 1
    fi

    local missing_vars=()
    local found_vars=()

    # Check core variables
    for var in "${CORE_VARS[@]}"; do
        if grep -q "^${var}=" "$file" || grep -q "^#.*${var}=" "$file"; then
            found_vars+=("$var")
        else
            missing_vars+=("$var")
        fi
    done

    # Check K8s variables for relevant files
    if [[ "$file_type" != "template" ]]; then
        for var in "${K8S_VARS[@]}"; do
            if grep -q "^${var}=" "$file" || grep -q "^#.*${var}=" "$file"; then
                found_vars+=("$var")
            else
                missing_vars+=("$var")
            fi
        done
    fi

    # Report results
    print_success "Found ${#found_vars[@]} variables"

    if [[ ${#missing_vars[@]} -gt 0 ]]; then
        print_warning "Missing variables:"
        for var in "${missing_vars[@]}"; do
            echo "  - $var"
        done
    fi

    # Check for old VITE_MAILGUN variables
    if grep -q "VITE_MAILGUN" "$file"; then
        print_error "Found deprecated VITE_MAILGUN variables (should be MAILGUN_*)"
    fi

    # Check variable format
    local malformed_vars=()
    while IFS= read -r line; do
        if [[ "$line" =~ ^[A-Z_]+=.* ]]; then
            local var_name="${line%%=*}"
            if [[ ! "$var_name" =~ ^[A-Z_][A-Z0-9_]*$ ]]; then
                malformed_vars+=("$var_name")
            fi
        fi
    done < "$file"

    if [[ ${#malformed_vars[@]} -gt 0 ]]; then
        print_warning "Malformed variable names:"
        for var in "${malformed_vars[@]}"; do
            echo "  - $var"
        done
    fi

    echo ""
}

validate_consistency() {
    print_section "Cross-file Consistency Check"

    # Extract variable names from each file
    local example_vars=()
    local env_vars=()
    local prod_vars=()

    if [[ -f ".env.example" ]]; then
        while IFS= read -r line; do
            if [[ "$line" =~ ^[A-Z_]+=.* ]]; then
                example_vars+=("${line%%=*}")
            fi
        done < ".env.example"
    fi

    if [[ -f ".env" ]]; then
        while IFS= read -r line; do
            if [[ "$line" =~ ^[A-Z_]+=.* ]]; then
                env_vars+=("${line%%=*}")
            fi
        done < ".env"
    fi

    if [[ -f ".env.production" ]]; then
        while IFS= read -r line; do
            if [[ "$line" =~ ^[A-Z_]+=.* ]]; then
                prod_vars+=("${line%%=*}")
            fi
        done < ".env.production"
    fi

    # Check if .env and .env.production have all variables from .env.example
    local missing_in_env=()
    local missing_in_prod=()

    for var in "${example_vars[@]}"; do
        if [[ ! " ${env_vars[@]} " =~ " ${var} " ]]; then
            missing_in_env+=("$var")
        fi
        if [[ ! " ${prod_vars[@]} " =~ " ${var} " ]]; then
            missing_in_prod+=("$var")
        fi
    done

    if [[ ${#missing_in_env[@]} -eq 0 ]]; then
        print_success ".env has all variables from .env.example"
    else
        print_warning ".env missing variables from .env.example:"
        for var in "${missing_in_env[@]}"; do
            echo "  - $var"
        done
    fi

    if [[ ${#missing_in_prod[@]} -eq 0 ]]; then
        print_success ".env.production has all variables from .env.example"
    else
        print_warning ".env.production missing variables from .env.example:"
        for var in "${missing_in_prod[@]}"; do
            echo "  - $var"
        done
    fi

    echo ""
}

validate_k8s_template() {
    print_section "Kubernetes Template Validation"

    local template_file="k8s/ingress.yaml.template"

    if [[ ! -f "$template_file" ]]; then
        print_error "Template file not found: $template_file"
        return 1
    fi

    # Check for template variables
    local template_vars=()
    while IFS= read -r line; do
        if [[ "$line" =~ \$\{([A-Z_][A-Z0-9_]*)\} ]]; then
            local var_name="${BASH_REMATCH[1]}"
            if [[ ! " ${template_vars[@]} " =~ " ${var_name} " ]]; then
                template_vars+=("$var_name")
            fi
        fi
    done < "$template_file"

    print_success "Found ${#template_vars[@]} template variables:"
    for var in "${template_vars[@]}"; do
        echo "  - \${$var}"
    done

    # Check if template variables are defined in env files
    for var in "${template_vars[@]}"; do
        local found_in_files=()

        if grep -q "^${var}=" ".env.example" 2>/dev/null; then
            found_in_files+=(".env.example")
        fi
        if grep -q "^${var}=" ".env" 2>/dev/null; then
            found_in_files+=(".env")
        fi
        if grep -q "^${var}=" ".env.production" 2>/dev/null; then
            found_in_files+=(".env.production")
        fi

        if [[ ${#found_in_files[@]} -gt 0 ]]; then
            print_success "$var defined in: ${found_in_files[*]}"
        else
            print_error "$var not defined in any environment file"
        fi
    done

    echo ""
}

main() {
    print_header

    # Validate individual files
    if [[ -f ".env.example" ]]; then
        validate_file ".env.example" "template"
    fi

    if [[ -f ".env" ]]; then
        validate_file ".env" "development"
    fi

    if [[ -f ".env.production" ]]; then
        validate_file ".env.production" "production"
    fi

    # Cross-file validation
    validate_consistency

    # Kubernetes template validation
    validate_k8s_template

    print_section "Summary"
    print_success "Environment validation complete!"
    echo ""
    echo "💡 Tips:"
    echo "   - Copy .env.example to .env for local development"
    echo "   - Use .env.production for production deployments"
    echo "   - Run './deploy-k8s.sh --dry-run' to test Kubernetes deployment"
    echo "   - All Mailgun variables use server-side naming (no VITE_ prefix)"
    echo ""
}

main "$@"