#!/bin/bash
# =============================================================================
# GitLab CI/CD Configuration Validator
# =============================================================================
# Purpose: Validate .gitlab-ci.yml configuration and check prerequisites
# Usage: ./scripts/validate_gitlab_cicd.sh
# =============================================================================

set -euo pipefail

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m'

print_header() {
    echo -e "\n${CYAN}==============================================================================${NC}"
    echo -e "${CYAN}$1${NC}"
    echo -e "${CYAN}==============================================================================${NC}\n"
}

print_success() {
    echo -e "${GREEN}[✓]${NC} $1"
}

print_error() {
    echo -e "${RED}[✗]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[!]${NC} $1"
}

print_info() {
    echo -e "${BLUE}[i]${NC} $1"
}

# =============================================================================
# Validation Functions
# =============================================================================

validate_gitlab_ci_file() {
    print_header "1. Validating .gitlab-ci.yml Syntax"

    if [ ! -f .gitlab-ci.yml ]; then
        print_error ".gitlab-ci.yml not found in current directory"
        return 1
    fi
    print_success ".gitlab-ci.yml file exists"

    # Check if gitlab-ci-local is installed for local validation
    if command -v gitlab-ci-local &> /dev/null; then
        print_info "Validating syntax with gitlab-ci-local..."
        if gitlab-ci-local --list 2>&1 | grep -q "build:docker"; then
            print_success "Syntax validation passed"
        else
            print_error "Syntax validation failed"
            return 1
        fi
    else
        print_warning "gitlab-ci-local not installed (optional, for local validation)"
        print_info "Install: npm install -g gitlab-ci-local"
    fi

    # Check required stages
    print_info "Checking required stages..."
    for stage in "build" "test" "deploy"; do
        if grep -q "\- $stage" .gitlab-ci.yml; then
            print_success "Stage '$stage' defined"
        else
            print_error "Stage '$stage' missing"
            return 1
        fi
    done

    return 0
}

validate_docker_config() {
    print_header "2. Validating Docker Configuration"

    # Check Docker availability
    if ! command -v docker &> /dev/null; then
        print_error "Docker is not installed"
        return 1
    fi
    print_success "Docker installed: $(docker --version)"

    # Check Docker daemon
    if ! docker info &> /dev/null; then
        print_error "Docker daemon is not running"
        return 1
    fi
    print_success "Docker daemon running"

    # Check BuildKit support
    if docker buildx version &> /dev/null; then
        print_success "BuildKit available: $(docker buildx version | head -n1)"
    else
        print_warning "BuildKit not available (will use legacy builder)"
    fi

    # Check Dockerfile
    if [ -f Dockerfile.foxhunt-build ]; then
        print_success "Dockerfile.foxhunt-build exists"
    else
        print_error "Dockerfile.foxhunt-build not found"
        return 1
    fi

    return 0
}

validate_docker_hub_config() {
    print_header "3. Validating Docker Hub Configuration"

    # Check if Docker Hub credentials are set (for local testing)
    if [ -n "${DOCKER_HUB_USERNAME:-}" ] && [ -n "${DOCKER_HUB_PASSWORD:-}" ]; then
        print_success "Docker Hub credentials found in environment"

        # Test Docker Hub login
        print_info "Testing Docker Hub authentication..."
        if echo "$DOCKER_HUB_PASSWORD" | docker login -u "$DOCKER_HUB_USERNAME" --password-stdin docker.io &> /dev/null; then
            print_success "Docker Hub authentication successful"
        else
            print_error "Docker Hub authentication failed"
            return 1
        fi
    else
        print_warning "Docker Hub credentials not set in environment (OK for GitLab CI/CD)"
        print_info "For GitLab CI/CD, set these in: Settings → CI/CD → Variables"
        print_info "  - DOCKER_HUB_USERNAME (your Docker Hub username)"
        print_info "  - DOCKER_HUB_PASSWORD (Docker Hub access token, NOT password)"
    fi

    # Check Docker Hub repository
    print_info "Checking Docker Hub repository configuration..."
    REPO=$(grep "DOCKER_HUB_REPO:" .gitlab-ci.yml | awk '{print $2}')
    if [ -n "$REPO" ]; then
        print_success "Docker Hub repository: $REPO"
    else
        print_error "DOCKER_HUB_REPO not defined in .gitlab-ci.yml"
        return 1
    fi

    return 0
}

validate_build_artifacts() {
    print_header "4. Validating Build Artifacts"

    # Check if hyperopt binaries exist
    print_info "Checking for hyperopt binaries..."
    local binaries=(
        "hyperopt_mamba2_demo"
        "hyperopt_dqn_demo"
        "hyperopt_ppo_demo"
        "hyperopt_tft_demo"
    )

    local missing_count=0
    for binary in "${binaries[@]}"; do
        if [ -f "target/release/$binary" ]; then
            print_success "$binary exists ($(du -h "target/release/$binary" | cut -f1))"
        else
            print_warning "$binary not found (will be built in CI/CD)"
            ((missing_count++))
        fi
    done

    if [ $missing_count -eq ${#binaries[@]} ]; then
        print_warning "No hyperopt binaries found locally (expected for clean checkout)"
        print_info "Binaries will be built during Docker image build"
    fi

    return 0
}

validate_gitlab_runner() {
    print_header "5. Validating GitLab Runner Configuration"

    # Check if gitlab-runner is installed
    if command -v gitlab-runner &> /dev/null; then
        print_success "GitLab Runner installed: $(gitlab-runner --version | head -n1)"

        # Check registered runners
        print_info "Checking registered runners..."
        if gitlab-runner list 2>&1 | grep -q "Executor"; then
            print_success "GitLab Runner registered"
            gitlab-runner list 2>&1 | grep "Executor" | while read -r line; do
                print_info "  $line"
            done
        else
            print_warning "No GitLab Runners registered locally"
        fi
    else
        print_warning "GitLab Runner not installed locally (OK if using GitLab.com shared runners)"
        print_info "For self-hosted runner: https://docs.gitlab.com/runner/install/"
    fi

    # Check .gitlab-ci.yml for runner tags
    print_info "Checking runner tags in .gitlab-ci.yml..."
    if grep -q "tags:" .gitlab-ci.yml; then
        grep "tags:" .gitlab-ci.yml | while read -r line; do
            print_info "  $line"
        done
        print_success "Runner tags configured"
    else
        print_warning "No runner tags specified (will use any available runner)"
    fi

    return 0
}

validate_ci_variables() {
    print_header "6. Validating CI/CD Variables"

    print_info "Required GitLab CI/CD Variables (set in GitLab UI):"
    print_info "  - DOCKER_HUB_USERNAME (required)"
    print_info "  - DOCKER_HUB_PASSWORD (required, use access token)"

    print_info ""
    print_info "Optional CI/CD Variables:"
    print_info "  - SLACK_WEBHOOK_URL (for notifications)"
    print_info "  - DISCORD_WEBHOOK_URL (for notifications)"

    # Check if variables are referenced in .gitlab-ci.yml
    if grep -q "DOCKER_HUB_USERNAME" .gitlab-ci.yml && grep -q "DOCKER_HUB_PASSWORD" .gitlab-ci.yml; then
        print_success "Required variables referenced in .gitlab-ci.yml"
    else
        print_error "Required variables not referenced in .gitlab-ci.yml"
        return 1
    fi

    return 0
}

validate_deployment_config() {
    print_header "7. Validating Deployment Configuration"

    # Check deployment stages
    if grep -q "deploy:runpod:" .gitlab-ci.yml; then
        print_success "RunPod deployment stage configured"
    else
        print_warning "RunPod deployment stage not found"
    fi

    if grep -q "deploy:runpod-staging:" .gitlab-ci.yml; then
        print_success "Staging deployment stage configured"
    else
        print_warning "Staging deployment stage not found"
    fi

    # Check manual approval for production
    if grep -q "when: manual" .gitlab-ci.yml; then
        print_success "Manual approval configured for production deployment"
    else
        print_warning "No manual approval for production (all deployments automatic)"
    fi

    # Check environment configuration
    if grep -q "environment:" .gitlab-ci.yml; then
        print_success "Environment configuration present"
    else
        print_warning "No environment configuration"
    fi

    return 0
}

simulate_local_build() {
    print_header "8. Simulating Local Build (Optional)"

    read -p "Run local Docker build simulation? (y/N) " -n 1 -r
    echo
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        print_info "Skipping local build simulation"
        return 0
    fi

    print_info "Building Docker image locally (this may take 5-10 minutes)..."

    export DOCKER_BUILDKIT=1
    export GIT_COMMIT=$(git rev-parse --short HEAD 2>/dev/null || echo "unknown")
    export BUILD_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')

    if docker build \
        -f Dockerfile.foxhunt-build \
        -t jgrusewski/foxhunt:test-local \
        --build-arg GIT_COMMIT="$GIT_COMMIT" \
        --build-arg BUILD_DATE="$BUILD_DATE" \
        . 2>&1 | tail -20; then
        print_success "Local Docker build completed"

        # Validate binaries in image
        print_info "Validating binaries in image..."
        local binaries=(
            "hyperopt_mamba2_demo"
            "hyperopt_dqn_demo"
            "hyperopt_ppo_demo"
            "hyperopt_tft_demo"
        )

        for binary in "${binaries[@]}"; do
            if docker run --rm --entrypoint="" jgrusewski/foxhunt:test-local test -f "/usr/local/bin/$binary"; then
                print_success "$binary exists in image"
            else
                print_error "$binary missing in image"
                return 1
            fi
        done

        # Show image size
        local size=$(docker image inspect jgrusewski/foxhunt:test-local --format='{{.Size}}' | awk '{ sum=$1; hum[1024**3]="GB"; hum[1024**2]="MB"; hum[1024]="KB"; for (x=1024**3; x>=1024; x/=1024) { if (sum>=x) { printf "%.2f %s", sum/x, hum[x]; break } }}')
        print_info "Image size: $size"

    else
        print_error "Local Docker build failed"
        return 1
    fi

    return 0
}

# =============================================================================
# Main Execution
# =============================================================================

main() {
    print_header "GitLab CI/CD Configuration Validator"

    print_info "Current directory: $(pwd)"
    print_info "Git repository: $(git remote get-url origin 2>/dev/null || echo 'Not a git repository')"
    print_info "Git branch: $(git branch --show-current 2>/dev/null || echo 'Unknown')"
    print_info "Git commit: $(git rev-parse --short HEAD 2>/dev/null || echo 'Unknown')"

    local exit_code=0

    # Run all validations
    validate_gitlab_ci_file || exit_code=1
    validate_docker_config || exit_code=1
    validate_docker_hub_config || exit_code=1
    validate_build_artifacts || exit_code=1
    validate_gitlab_runner || exit_code=1
    validate_ci_variables || exit_code=1
    validate_deployment_config || exit_code=1

    # Optional: simulate local build
    if [ $exit_code -eq 0 ]; then
        simulate_local_build || exit_code=1
    fi

    # Final summary
    print_header "Validation Summary"

    if [ $exit_code -eq 0 ]; then
        print_success "All validations passed!"
        print_info ""
        print_info "Next steps:"
        print_info "  1. Set GitLab CI/CD variables in GitLab UI (if not already set)"
        print_info "     Settings → CI/CD → Variables"
        print_info "       - DOCKER_HUB_USERNAME"
        print_info "       - DOCKER_HUB_PASSWORD (Docker Hub access token)"
        print_info ""
        print_info "  2. Push to main branch to trigger pipeline:"
        print_info "     git push origin main"
        print_info ""
        print_info "  3. Monitor pipeline in GitLab:"
        print_info "     Project → CI/CD → Pipelines"
        print_info ""
        print_info "  4. Manual approval required for production deployment"
        print_info ""
    else
        print_error "Some validations failed"
        print_info ""
        print_info "Please fix the issues above before enabling GitLab CI/CD"
        print_info ""
    fi

    exit $exit_code
}

# Run main function
main "$@"