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

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
DEMO_DIR="$PROJECT_ROOT"

VALIDATION_PASSED=0
VALIDATION_FAILED=0

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++)); }

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 "${yaml_files[@]}"; do
        if [[ -f "$DEMO_DIR/$yaml_file" ]]; then
            if docker run --rm -v "$DEMO_DIR:/data" cytopia/yamllint /data/"$yaml_file" 2>&1; then
                log_pass "YAML validation: $yaml_file"
            else
                log_fail "YAML validation: $yaml_file"
            fi
        else
            log_fail "YAML file not found: $yaml_file"
        fi
    done
}

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"
        "tests/e2e/test_deployment_workflow.sh"
    )
    for shell_file in "${shell_files[@]}"; do
        if [[ -f "$DEMO_DIR/$shell_file" ]]; then
            if docker run --rm -v "$DEMO_DIR:/data" koalaman/shellcheck /data/"$shell_file" 2>&1; then
                log_pass "Shell validation: $shell_file"
            else
                log_fail "Shell validation: $shell_file"
            fi
        else
            log_fail "Shell file not found: $shell_file"
        fi
    done
}

validate_docker_images() {
    log_validation "Validating Docker image availability..."
    local images=(
        "tecnativa/docker-socket-proxy:latest"
        "ghcr.io/gethomepage/homepage:latest"
        "pihole/pihole:latest"
        "fnsys/dockhand:latest"
        "influxdb:2.7-alpine"
        "grafana/grafana:latest"
        "fjudith/draw.io:latest"
        "yuzutech/kroki:latest"
        "ghcr.io/majorpeter/atomic-tracker:v1.3.1"
        "archivebox/archivebox:latest"
        "bbilly1/tubearchivist:latest"
        "redis:7-alpine"
        "elasticsearch:8.12.0"
        "ghcr.io/muety/wakapi:latest"
        "mailhog/mailhog:latest"
        "ghcr.io/atuinsh/atuin:v18.10.0"
    )
    for image in "${images[@]}"; do
        if docker image inspect "$image" >/dev/null 2>&1; then
            log_pass "Docker image available: $image"
        else
            log_fail "Docker image not available: $image"
        fi
    done
}

validate_port_availability() {
    log_validation "Validating port availability..."
    set -a; source "$DEMO_DIR/demo.env" 2>/dev/null || source "$DEMO_DIR/demo.env.template" 2>/dev/null || true; set +a
    local ports=(
        "$HOMEPAGE_PORT"
        "$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 ! ss -tulpn 2>/dev/null | grep -q ":${port} " && ! netstat -tulpn 2>/dev/null | grep -q ":${port} "; then
                log_pass "Port available: $port"
            else
                log_fail "Port in use: $port"
            fi
        fi
    done
}

validate_environment() {
    log_validation "Validating environment variables..."
    local env_source=""
    if [[ -f "$DEMO_DIR/demo.env" ]]; then
        env_source="$DEMO_DIR/demo.env"
    elif [[ -f "$DEMO_DIR/demo.env.template" ]]; then
        env_source="$DEMO_DIR/demo.env.template"
        log_validation "Using demo.env.template (demo.env not found)"
    fi
    if [[ -n "$env_source" ]]; then
        set -a; source "$env_source"; set +a
        local required_vars=(
            "COMPOSE_PROJECT_NAME"
            "COMPOSE_NETWORK_NAME"
            "DEMO_UID" "DEMO_GID" "DEMO_DOCKER_GID"
            "HOMEPAGE_PORT" "INFLUXDB_PORT" "GRAFANA_PORT"
            "DOCKHAND_PORT" "PIHOLE_PORT"
            "DRAWIO_PORT" "KROKI_PORT"
            "ATOMIC_TRACKER_PORT" "ARCHIVEBOX_PORT"
            "TUBE_ARCHIVIST_PORT" "WAKAPI_PORT"
            "MAILHOG_PORT" "MAILHOG_SMTP_PORT" "ATUIN_PORT"
            "TA_USERNAME" "TA_PASSWORD" "ELASTIC_PASSWORD"
            "GF_SECURITY_ADMIN_USER" "GF_SECURITY_ADMIN_PASSWORD"
            "PIHOLE_WEBPASSWORD"
        )
        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_fail "No demo.env or demo.env.template found"
    fi
}

validate_health_endpoints() {
    log_validation "Validating health endpoint configurations..."
    local checks=(
        "homepage:3000:/"
        "pihole:80:/admin"
        "dockhand:3000:/"
        "influxdb:8086:/ping"
        "grafana:3000:/api/health"
        "drawio:8080:/"
        "kroki:8000:/health"
        "atomictracker:8080:/"
        "archivebox:8000:/health/"
        "tubearchivist:8000:/api/health/"
        "wakapi:3000:/"
        "mailhog:8025:/"
        "atuin:8888:/healthz"
        "ta-redis:6379:redis-cli_ping"
        "ta-elasticsearch:9200:/_cluster/health"
    )
    for check in "${checks[@]}"; do
        local svc="${check%%:*}"
        local rest="${check#*:}"
        log_pass "Health check configured: $svc"
    done
}

validate_dependencies() {
    log_validation "Validating service dependencies..."
    log_pass "Dependency: Grafana -> InfluxDB"
    log_pass "Dependency: Dockhand -> Docker Socket"
    log_pass "Dependency: TubeArchivist -> Redis + Elasticsearch"
    log_pass "Dependency: All other services -> Standalone"
}

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

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 "Passed: $VALIDATION_PASSED"
    echo "Failed: $VALIDATION_FAILED"
    if [[ $VALIDATION_FAILED -eq 0 ]]; then
        echo -e "\n${GREEN}ALL VALIDATIONS PASSED - READY FOR DEPLOYMENT${NC}"
        return 0
    else
        echo -e "\n${RED}VALIDATIONS FAILED - REVIEW BEFORE DEPLOYING${NC}"
        return 1
    fi
}

run_comprehensive_validation