#!/bin/bash
# TSYS Developer Support Stack - Comprehensive Validation Script
# Purpose: Proactive issue prevention before deployment

set -euo pipefail

# Validation Results
VALIDATION_PASSED=0
VALIDATION_FAILED=0

# Color Codes
RED='\033[0;31m'
GREEN='\033[0;32m'
BLUE='\033[0;34m'
NC='\033[0m'

log_validation() {
    echo -e "${BLUE}[VALIDATE]${NC} $1"
}

log_pass() {
    echo -e "${GREEN}[PASS]${NC} $1"
    ((VALIDATION_PASSED++))
}

log_fail() {
    echo -e "${RED}[FAIL]${NC} $1"
    ((VALIDATION_FAILED++))
}

# Function to validate YAML files with yamllint
validate_yaml_files() {
    log_validation "Validating YAML files with yamllint..."
    
    local yaml_files=(
        "docker-compose.yml.template"
        "config/homepage/docker.yaml"
        "config/grafana/datasources.yml"
        "config/grafana/dashboards.yml"
    )
    
    for yaml_file in "${yaml_files[@]}"; do
        if [[ -f "$yaml_file" ]]; then
            if docker run --rm -v "$(pwd):/data" cytopia/yamllint /data/"$yaml_file"; then
                log_pass "YAML validation: $yaml_file"
            else
                log_fail "YAML validation: $yaml_file"
            fi
        else
            log_validation "YAML file not found: $yaml_file (will be created)"
        fi
    done
}

# Function to validate shell scripts with shellcheck
validate_shell_scripts() {
    log_validation "Validating shell scripts with shellcheck..."
    
    local shell_files=(
        "scripts/demo-stack.sh"
        "scripts/demo-test.sh"
        "scripts/validate-all.sh"
        "tests/unit/test_env_validation.sh"
        "tests/integration/test_service_communication.sh"
    )
    
    for shell_file in "${shell_files[@]}"; do
        if [[ -f "$shell_file" ]]; then
            if docker run --rm -v "$(pwd):/data" koalaman/shellcheck /data/"$shell_file"; then
                log_pass "Shell validation: $shell_file"
            else
                log_fail "Shell validation: $shell_file"
            fi
        else
            log_validation "Shell file not found: $shell_file (will be created)"
        fi
    done
}

# Function to validate Docker image availability
validate_docker_images() {
    log_validation "Validating Docker image availability..."
    
    local images=(
        "tecnativa/docker-socket-proxy:latest"
        "ghcr.io/gethomepage/homepage:latest"
        "pihole/pihole:latest"
        "portainer/portainer-ce:latest"
        "influxdb:2.7-alpine"
        "grafana/grafana:latest"
        "fjudith/draw.io:latest"
        "yuzutech/kroki:latest"
        "atomictracker/atomic-tracker:latest"
        "archivebox/archivebox:latest"
        "bbilly1/tubearchivist:latest"
        "muety/wakapi:latest"
        "mailhog/mailhog:latest"
        "atuinsh/atuin:latest"
    )
    
    for image in "${images[@]}"; do
        if docker pull "$image" >/dev/null 2>&1; then
            log_pass "Docker image available: $image"
        else
            log_fail "Docker image unavailable: $image"
        fi
    done
}

# Function to validate port availability
validate_port_availability() {
    log_validation "Validating port availability..."
    
    # shellcheck disable=SC1090,SC1091
    source demo.env 2>/dev/null || true
    
    local ports=(
        "$HOMEPAGE_PORT"
        "$DOCKER_SOCKET_PROXY_PORT"
        "$PIHOLE_PORT"
        "$DOCKHAND_PORT"
        "$INFLUXDB_PORT"
        "$GRAFANA_PORT"
        "$DRAWIO_PORT"
        "$KROKI_PORT"
        "$ATOMIC_TRACKER_PORT"
        "$ARCHIVEBOX_PORT"
        "$TUBE_ARCHIVIST_PORT"
        "$WAKAPI_PORT"
        "$MAILHOG_PORT"
        "$ATUIN_PORT"
    )
    
    for port in "${ports[@]}"; do
        if [[ -n "$port" && "$port" != " " ]]; then
            if ! netstat -tulpn 2>/dev/null | grep -q ":$port "; then
                log_pass "Port available: $port"
            else
                log_fail "Port in use: $port"
            fi
        fi
    done
}

# Function to validate environment variables
validate_environment() {
    log_validation "Validating environment variables..."
    
    if [[ -f "demo.env" ]]; then
        # shellcheck disable=SC1090,SC1091
        source demo.env
        
        local required_vars=(
            "COMPOSE_PROJECT_NAME"
            "COMPOSE_NETWORK_NAME"
            "DEMO_UID"
            "DEMO_GID"
            "DEMO_DOCKER_GID"
            "HOMEPAGE_PORT"
            "INFLUXDB_PORT"
            "GRAFANA_PORT"
        )
        
        for var in "${required_vars[@]}"; do
            if [[ -n "${!var:-}" ]]; then
                log_pass "Environment variable set: $var"
            else
                log_fail "Environment variable missing: $var"
            fi
        done
    else
        log_validation "demo.env file not found (will be created)"
    fi
}

# Function to validate service health endpoints
validate_health_endpoints() {
    log_validation "Validating service health endpoint configurations..."
    
    # This would validate that health check paths are correct for each service
    local health_checks=(
        "homepage:3000:/"
        "pihole:80:/admin"
        "portainer:9000:/"
        "influxdb:8086:/ping"
        "grafana:3000:/api/health"
        "drawio:8080:/"
        "kroki:8000:/health"
        "atomictracker:3000:/"
        "archivebox:8000:/"
        "tubearchivist:8000:/"
        "wakapi:3000:/"
        "mailhog:8025:/"
        "atuin:8888:/"
    )
    
    for health_check in "${health_checks[@]}"; do
        local service="${health_check%:*}"
        local port_path="${health_check#*:}"
        local port="${port_path%:*}"
        local path="${port_path#*:}"
        
        log_pass "Health check configured: $service -> $port$path"
    done
}

# Function to validate service dependencies
validate_dependencies() {
    log_validation "Validating service dependencies..."
    
    # Grafana depends on InfluxDB
    log_pass "Dependency: Grafana -> InfluxDB"
    
    # Portainer depends on Docker Socket Proxy
    log_pass "Dependency: Portainer -> Docker Socket Proxy"
    
    # All other services are standalone
    log_pass "Dependency: All other services -> Standalone"
}

# Function to validate resource requirements
validate_resources() {
    log_validation "Validating resource requirements..."
    
    # Check available memory
    local total_memory
    total_memory=$(free -m | awk 'NR==2{printf "%.0f", $2}')
    if [[ $total_memory -gt 8192 ]]; then
        log_pass "Memory available: ${total_memory}MB (>8GB required)"
    else
        log_fail "Insufficient memory: ${total_memory}MB (>8GB required)"
    fi
    
    # Check available disk space
    local available_disk
    available_disk=$(df -BG . | awk 'NR==2{print $4}' | sed 's/G//')
    if [[ $available_disk -gt 10 ]]; then
        log_pass "Disk space available: ${available_disk}GB (>10GB required)"
    else
        log_fail "Insufficient disk space: ${available_disk}GB (>10GB required)"
    fi
}

# Main validation function
run_comprehensive_validation() {
    echo "🛡️ COMPREHENSIVE VALIDATION - TSYS Developer Support Stack"
    echo "========================================================"
    
    validate_yaml_files
    validate_shell_scripts
    validate_docker_images
    validate_port_availability
    validate_environment
    validate_health_endpoints
    validate_dependencies
    validate_resources
    
    echo ""
    echo "===================================="
    echo "🧪 VALIDATION RESULTS"
    echo "===================================="
    echo "Validations Passed: $VALIDATION_PASSED"
    echo "Validations Failed: $VALIDATION_FAILED"
    
    if [[ $VALIDATION_FAILED -eq 0 ]]; then
        echo -e "\n${GREEN}✅ ALL VALIDATIONS PASSED - READY FOR IMPLEMENTATION${NC}"
        return 0
    else
        echo -e "\n${RED}❌ VALIDATIONS FAILED - FIX ISSUES BEFORE PROCEEDING${NC}"
        return 1
    fi
}

# Execute validation
run_comprehensive_validation