#!/bin/bash
# Migration Testing Framework
# Provides comprehensive testing for migration procedures including staging environment validation

# Import error handling library
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/lib/error_handling.sh"

# Configuration
readonly STAGING_PREFIX="staging"
readonly PRODUCTION_PREFIX="production"
readonly TEST_DATA_DIR="/opt/migration/test_data"
readonly STAGING_NETWORK="staging-network"
readonly TEST_RESULTS_DIR="/opt/migration/test_results"
readonly MIGRATION_TESTS_CONFIG="/opt/migration/configs/migration_tests.yml"

# Test configuration
readonly TEST_DATABASE_SIZE_MB=100
readonly TEST_TIMEOUT_MINUTES=30
readonly HEALTH_CHECK_RETRIES=10
readonly PERFORMANCE_BASELINE_FILE="/opt/migration/performance_baseline.json"

# Cleanup function
cleanup_staging() {
    log_info "Cleaning up staging environment..."
    
    # Remove staging containers
    docker ps -a --filter "name=${STAGING_PREFIX}_*" -q | xargs -r docker rm -f 2>/dev/null || true
    
    # Remove staging networks
    docker network ls --filter "name=${STAGING_PREFIX}_*" -q | xargs -r docker network rm 2>/dev/null || true
    
    # Remove staging volumes
    docker volume ls --filter "name=${STAGING_PREFIX}_*" -q | xargs -r docker volume rm 2>/dev/null || true
    
    # Clean up test data
    if [[ -d "$TEST_DATA_DIR/staging" ]]; then
        rm -rf "$TEST_DATA_DIR/staging"
    fi
    
    log_info "Staging environment cleanup completed"
}

# Rollback function for failed tests
rollback_staging() {
    log_info "Rolling back staging environment..."
    
    # Stop all staging services
    docker service ls --filter "name=${STAGING_PREFIX}_*" -q | xargs -r docker service rm 2>/dev/null || true
    
    # Clean up everything
    cleanup_staging
    
    log_info "Staging environment rollback completed"
}

# Function to create test data
create_test_data() {
    local data_type=$1
    local size_mb=${2:-10}
    
    log_step "Creating test data: $data_type (${size_mb}MB)..."
    
    mkdir -p "$TEST_DATA_DIR/generated"
    
    case $data_type in
        "database")
            create_test_database_data "$size_mb"
            ;;
        "files")
            create_test_file_data "$size_mb"
            ;;
        "images")
            create_test_image_data "$size_mb"
            ;;
        "documents")
            create_test_document_data "$size_mb"
            ;;
        *)
            log_error "Unknown test data type: $data_type"
            return 1
            ;;
    esac
}

# Function to create test database data
create_test_database_data() {
    local size_mb=$1
    local sql_file="$TEST_DATA_DIR/generated/test_database_${size_mb}mb.sql"
    
    log_info "Generating test database data (${size_mb}MB)..."
    
    # Calculate number of records needed
    local records_needed=$((size_mb * 1024 / 2))  # Rough estimate: 2KB per record
    
    cat > "$sql_file" << EOF
-- Test Database Schema and Data
-- Generated: $(date)
-- Size target: ${size_mb}MB

-- Create test tables
CREATE TABLE IF NOT EXISTS test_users (
    id SERIAL PRIMARY KEY,
    username VARCHAR(50) UNIQUE NOT NULL,
    email VARCHAR(100) UNIQUE NOT NULL,
    password_hash VARCHAR(255) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    profile_data JSONB,
    is_active BOOLEAN DEFAULT true
);

CREATE TABLE IF NOT EXISTS test_posts (
    id SERIAL PRIMARY KEY,
    user_id INTEGER REFERENCES test_users(id),
    title VARCHAR(200) NOT NULL,
    content TEXT,
    tags VARCHAR(500),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    view_count INTEGER DEFAULT 0,
    metadata JSONB
);

CREATE TABLE IF NOT EXISTS test_files (
    id SERIAL PRIMARY KEY,
    filename VARCHAR(255) NOT NULL,
    file_path TEXT NOT NULL,
    mime_type VARCHAR(100),
    file_size BIGINT,
    checksum VARCHAR(64),
    uploaded_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    user_id INTEGER REFERENCES test_users(id)
);

-- Create indexes
CREATE INDEX idx_users_email ON test_users(email);
CREATE INDEX idx_posts_user_id ON test_posts(user_id);
CREATE INDEX idx_posts_created_at ON test_posts(created_at);
CREATE INDEX idx_files_user_id ON test_files(user_id);

-- Generate test data
EOF

    # Generate user data
    log_info "Generating user test data..."
    for ((i=1; i<=100; i++)); do
        cat >> "$sql_file" << EOF
INSERT INTO test_users (username, email, password_hash, profile_data) VALUES 
    ('testuser$i', 'user$i@testdomain.com', 'hash_$i', '{"bio": "Test user $i", "preferences": {"theme": "dark", "notifications": true}}');
EOF
    done
    
    # Generate posts data
    log_info "Generating posts test data..."
    for ((i=1; i<=records_needed; i++)); do
        local user_id=$((1 + i % 100))
        cat >> "$sql_file" << EOF
INSERT INTO test_posts (user_id, title, content, tags, metadata) VALUES 
    ($user_id, 'Test Post $i', 'This is test content for post $i. It contains various characters and data to simulate real content. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.', 'tag1,tag2,test$i', '{"views": $((i % 1000)), "featured": $((i % 10 == 0))}');
EOF
        
        # Add batch every 1000 records to avoid huge memory usage
        if ((i % 1000 == 0)); then
            echo "-- Progress: $i/$records_needed records" >> "$sql_file"
        fi
    done
    
    # Generate file metadata
    log_info "Generating file metadata test data..."
    for ((i=1; i<=500; i++)); do
        local user_id=$((1 + i % 100))
        cat >> "$sql_file" << EOF
INSERT INTO test_files (filename, file_path, mime_type, file_size, checksum, user_id) VALUES 
    ('testfile$i.txt', '/data/files/testfile$i.txt', 'text/plain', $((1024 + i * 100)), 'sha256_hash_$i', $user_id);
EOF
    done
    
    log_success "Test database data generated: $sql_file"
    return 0
}

# Function to create test file data
create_test_file_data() {
    local size_mb=$1
    local files_dir="$TEST_DATA_DIR/generated/test_files"
    
    mkdir -p "$files_dir"
    
    log_info "Generating test files (${size_mb}MB)..."
    
    # Create files of various sizes
    local remaining_mb=$size_mb
    local file_count=0
    
    while [[ $remaining_mb -gt 0 ]]; do
        local file_size_mb=$((1 + remaining_mb % 5))  # Files between 1-5MB
        if [[ $file_size_mb -gt $remaining_mb ]]; then
            file_size_mb=$remaining_mb
        fi
        
        ((file_count++))
        local filename="testfile_${file_count}.dat"
        
        # Generate random data
        dd if=/dev/urandom of="$files_dir/$filename" bs=1M count=$file_size_mb 2>/dev/null
        
        remaining_mb=$((remaining_mb - file_size_mb))
    done
    
    log_success "Generated $file_count test files totaling ${size_mb}MB in $files_dir"
    return 0
}

# Function to create test image data
create_test_image_data() {
    local size_mb=$1
    local images_dir="$TEST_DATA_DIR/generated/test_images"
    
    mkdir -p "$images_dir"
    
    log_info "Generating test images (${size_mb}MB)..."
    
    # Use ImageMagick to create test images if available
    if command -v convert >/dev/null 2>&1; then
        local image_count=0
        local remaining_mb=$size_mb
        
        while [[ $remaining_mb -gt 0 ]] && [[ $image_count -lt 100 ]]; do
            ((image_count++))
            local width=$((800 + image_count * 10))
            local height=$((600 + image_count * 8))
            
            # Create a test image with random colors
            convert -size ${width}x${height} xc:"rgb($((image_count % 255)),$((image_count * 2 % 255)),$((image_count * 3 % 255)))" \
                -pointsize 50 -fill white -gravity center \
                -annotate +0+0 "Test Image $image_count" \
                "$images_dir/test_image_${image_count}.jpg" 2>/dev/null
            
            # Check file size and update remaining
            local file_size_mb=$(du -m "$images_dir/test_image_${image_count}.jpg" 2>/dev/null | cut -f1)
            remaining_mb=$((remaining_mb - file_size_mb))
            
            if [[ $remaining_mb -le 0 ]]; then
                break
            fi
        done
        
        log_success "Generated $image_count test images in $images_dir"
    else
        # Fall back to creating binary files
        log_warn "ImageMagick not available, creating binary test files instead"
        create_test_file_data "$size_mb"
    fi
    
    return 0
}

# Function to create test document data
create_test_document_data() {
    local size_mb=$1
    local docs_dir="$TEST_DATA_DIR/generated/test_documents"
    
    mkdir -p "$docs_dir"
    
    log_info "Generating test documents (${size_mb}MB)..."
    
    # Generate various document types
    local doc_count=0
    local target_size_bytes=$((size_mb * 1024 * 1024))
    local current_size=0
    
    while [[ $current_size -lt $target_size_bytes ]] && [[ $doc_count -lt 1000 ]]; do
        ((doc_count++))
        
        # Create different types of documents
        case $((doc_count % 4)) in
            0)
                # Text document
                create_test_text_document "$docs_dir" "$doc_count"
                ;;
            1)
                # CSV document
                create_test_csv_document "$docs_dir" "$doc_count"
                ;;
            2)
                # JSON document
                create_test_json_document "$docs_dir" "$doc_count"
                ;;
            3)
                # XML document
                create_test_xml_document "$docs_dir" "$doc_count"
                ;;
        esac
        
        # Update current size
        current_size=$(du -sb "$docs_dir" 2>/dev/null | cut -f1)
    done
    
    log_success "Generated $doc_count test documents in $docs_dir"
    return 0
}

# Function to create test text document
create_test_text_document() {
    local dir=$1
    local count=$2
    
    cat > "$dir/document_${count}.txt" << EOF
Test Document $count
Generated: $(date)
Type: Text Document

This is a test document created for migration testing purposes.
It contains various types of content to simulate real documents.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod 
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim 
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea 
commodo consequat.

Document ID: $count
Checksum: $(echo "test_$count" | sha256sum | cut -d' ' -f1)
Size: $(wc -c < "$dir/document_${count}.txt" 2>/dev/null || echo "unknown")
EOF
}

# Function to create test CSV document
create_test_csv_document() {
    local dir=$1
    local count=$2
    
    cat > "$dir/data_${count}.csv" << EOF
id,name,email,department,salary,hire_date,active
EOF
    
    # Add test data rows
    for ((i=1; i<=50; i++)); do
        echo "$i,Employee $i,emp${i}@company.com,Dept$((i % 5 + 1)),$((30000 + i * 1000)),2023-0$((i % 12 + 1))-01,true" >> "$dir/data_${count}.csv"
    done
}

# Function to create test JSON document
create_test_json_document() {
    local dir=$1
    local count=$2
    
    cat > "$dir/config_${count}.json" << EOF
{
  "document_id": $count,
  "version": "1.0",
  "created_at": "$(date -Iseconds)",
  "configuration": {
    "database": {
      "host": "localhost",
      "port": 5432,
      "name": "test_db_$count",
      "ssl": true
    },
    "cache": {
      "enabled": true,
      "ttl": 3600,
      "size_mb": 256
    },
    "features": [
      "feature_a",
      "feature_b",
      "feature_c_$count"
    ]
  },
  "metadata": {
    "tags": ["test", "migration", "document_$count"],
    "priority": $((count % 5 + 1)),
    "checksum": "sha256_test_$count"
  }
}
EOF
}

# Function to create test XML document
create_test_xml_document() {
    local dir=$1
    local count=$2
    
    cat > "$dir/manifest_${count}.xml" << EOF
<?xml version="1.0" encoding="UTF-8"?>
<manifest id="$count" version="1.0">
  <metadata>
    <created>$(date -Iseconds)</created>
    <type>test_document</type>
    <category>migration_test</category>
  </metadata>
  <content>
    <items>
      <item id="1" type="config" priority="high">
        <name>Test Configuration $count</name>
        <value>test_value_$count</value>
      </item>
      <item id="2" type="data" priority="medium">
        <name>Test Data $count</name>
        <value>$(echo "test_data_$count" | base64)</value>
      </item>
    </items>
  </content>
  <checksum algorithm="sha256">$(echo "manifest_$count" | sha256sum | cut -d' ' -f1)</checksum>
</manifest>
EOF
}

# Function to setup staging environment
setup_staging_environment() {
    log_step "Setting up staging environment..."
    
    # Create staging network
    if docker network create --driver bridge "$STAGING_NETWORK" 2>/dev/null; then
        log_success "Created staging network: $STAGING_NETWORK"
    else
        log_info "Staging network already exists: $STAGING_NETWORK"
    fi
    
    # Create staging data directory
    mkdir -p "$TEST_DATA_DIR/staging"
    chmod 755 "$TEST_DATA_DIR/staging"
    
    log_success "Staging environment setup completed"
    return 0
}

# Function to deploy service to staging
deploy_service_to_staging() {
    local service_name=$1
    local service_config=$2
    
    log_step "Deploying $service_name to staging environment..."
    
    # Create staging-specific configuration
    local staging_config="$TEST_DATA_DIR/staging/${service_name}_staging.yml"
    
    # Modify service configuration for staging
    sed "s/production/${STAGING_PREFIX}/g" "$service_config" > "$staging_config"
    sed -i "s/traefik-public/${STAGING_NETWORK}/g" "$staging_config"
    
    # Deploy to staging
    if docker-compose -f "$staging_config" up -d; then
        log_success "Service $service_name deployed to staging"
        
        # Wait for service to be ready
        wait_for_service "$service_name-staging" "docker-compose -f $staging_config ps | grep -q Up" 60 5
        
        return 0
    else
        log_error "Failed to deploy $service_name to staging"
        return 1
    fi
}

# Function to run migration test
run_migration_test() {
    local test_name=$1
    local source_service=$2
    local target_service=$3
    
    log_step "Running migration test: $test_name"
    
    local test_result_file="$TEST_RESULTS_DIR/${test_name}_$(date +%Y%m%d_%H%M%S).json"
    mkdir -p "$TEST_RESULTS_DIR"
    
    # Initialize test result
    cat > "$test_result_file" << EOF
{
  "test_name": "$test_name",
  "start_time": "$(date -Iseconds)",
  "source_service": "$source_service",
  "target_service": "$target_service",
  "status": "running",
  "phases": []
}
EOF

    # Phase 1: Pre-migration validation
    log_info "Phase 1: Pre-migration validation"
    local phase1_result=$(run_pre_migration_validation "$source_service")
    jq ".phases += [{\"phase\": \"pre_migration\", \"result\": \"$phase1_result\", \"timestamp\": \"$(date -Iseconds)\"}]" "$test_result_file" > "${test_result_file}.tmp" && mv "${test_result_file}.tmp" "$test_result_file"
    
    # Phase 2: Data migration
    log_info "Phase 2: Data migration"
    local phase2_result=$(run_data_migration_test "$source_service" "$target_service")
    jq ".phases += [{\"phase\": \"data_migration\", \"result\": \"$phase2_result\", \"timestamp\": \"$(date -Iseconds)\"}]" "$test_result_file" > "${test_result_file}.tmp" && mv "${test_result_file}.tmp" "$test_result_file"
    
    # Phase 3: Service migration
    log_info "Phase 3: Service migration"
    local phase3_result=$(run_service_migration_test "$source_service" "$target_service")
    jq ".phases += [{\"phase\": \"service_migration\", \"result\": \"$phase3_result\", \"timestamp\": \"$(date -Iseconds)\"}]" "$test_result_file" > "${test_result_file}.tmp" && mv "${test_result_file}.tmp" "$test_result_file"
    
    # Phase 4: Post-migration validation
    log_info "Phase 4: Post-migration validation"
    local phase4_result=$(run_post_migration_validation "$target_service")
    jq ".phases += [{\"phase\": \"post_migration\", \"result\": \"$phase4_result\", \"timestamp\": \"$(date -Iseconds)\"}]" "$test_result_file" > "${test_result_file}.tmp" && mv "${test_result_file}.tmp" "$test_result_file"
    
    # Phase 5: Performance testing
    log_info "Phase 5: Performance testing"
    local phase5_result=$(run_performance_test "$target_service")
    jq ".phases += [{\"phase\": \"performance_test\", \"result\": \"$phase5_result\", \"timestamp\": \"$(date -Iseconds)\"}]" "$test_result_file" > "${test_result_file}.tmp" && mv "${test_result_file}.tmp" "$test_result_file"
    
    # Determine overall test result
    local overall_result="success"
    if [[ "$phase1_result" != "success" ]] || [[ "$phase2_result" != "success" ]] || [[ "$phase3_result" != "success" ]] || [[ "$phase4_result" != "success" ]]; then
        overall_result="failed"
    elif [[ "$phase5_result" != "success" ]]; then
        overall_result="success_with_performance_issues"
    fi
    
    # Update final result
    jq ".status = \"$overall_result\" | .end_time = \"$(date -Iseconds)\"" "$test_result_file" > "${test_result_file}.tmp" && mv "${test_result_file}.tmp" "$test_result_file"
    
    if [[ "$overall_result" == "success" ]]; then
        log_success "Migration test $test_name completed successfully"
    else
        log_error "Migration test $test_name failed or had issues"
    fi
    
    log_info "Test results saved to: $test_result_file"
    return 0
}

# Function to run pre-migration validation
run_pre_migration_validation() {
    local service=$1
    
    log_info "Validating pre-migration state for $service..."
    
    # Check service health
    if ! docker ps | grep -q "$service"; then
        log_error "Service $service is not running"
        echo "failed"
        return 1
    fi
    
    # Check data consistency
    if ! validate_service_data "$service"; then
        log_error "Data validation failed for $service"
        echo "failed"
        return 1
    fi
    
    log_success "Pre-migration validation passed for $service"
    echo "success"
    return 0
}

# Function to run data migration test
run_data_migration_test() {
    local source_service=$1
    local target_service=$2
    
    log_info "Testing data migration from $source_service to $target_service..."
    
    # Create test data backup
    if ! create_service_backup "$source_service"; then
        log_error "Failed to create backup for $source_service"
        echo "failed"
        return 1
    fi
    
    # Simulate data migration
    if ! simulate_data_migration "$source_service" "$target_service"; then
        log_error "Data migration simulation failed"
        echo "failed"
        return 1
    fi
    
    log_success "Data migration test completed"
    echo "success"
    return 0
}

# Function to run service migration test
run_service_migration_test() {
    local source_service=$1
    local target_service=$2
    
    log_info "Testing service migration from $source_service to $target_service..."
    
    # Start target service
    if ! start_target_service "$target_service"; then
        log_error "Failed to start target service $target_service"
        echo "failed"
        return 1
    fi
    
    # Test service functionality
    if ! test_service_functionality "$target_service"; then
        log_error "Service functionality test failed for $target_service"
        echo "failed"
        return 1
    fi
    
    log_success "Service migration test completed"
    echo "success"
    return 0
}

# Function to run post-migration validation
run_post_migration_validation() {
    local service=$1
    
    log_info "Running post-migration validation for $service..."
    
    # Verify data integrity
    if ! verify_data_integrity "$service"; then
        log_error "Data integrity check failed for $service"
        echo "failed"
        return 1
    fi
    
    # Test all endpoints/functionality
    if ! test_service_endpoints "$service"; then
        log_error "Service endpoint tests failed for $service"
        echo "failed"
        return 1
    fi
    
    log_success "Post-migration validation passed for $service"
    echo "success"
    return 0
}

# Function to run performance test
run_performance_test() {
    local service=$1
    
    log_info "Running performance tests for $service..."
    
    # Load baseline performance data
    local baseline_file="$PERFORMANCE_BASELINE_FILE"
    if [[ ! -f "$baseline_file" ]]; then
        log_warn "No performance baseline found, creating new baseline"
        create_performance_baseline "$service"
        echo "success"
        return 0
    fi
    
    # Run performance tests
    local current_performance=$(measure_service_performance "$service")
    local baseline_performance=$(jq -r ".services.\"$service\".response_time_ms" "$baseline_file" 2>/dev/null || echo "1000")
    
    # Compare performance (allow 20% degradation)
    local performance_threshold=$(echo "$baseline_performance * 1.2" | bc -l)
    
    if (( $(echo "$current_performance > $performance_threshold" | bc -l) )); then
        log_warn "Performance degradation detected: ${current_performance}ms vs baseline ${baseline_performance}ms"
        echo "performance_degraded"
        return 1
    else
        log_success "Performance test passed: ${current_performance}ms vs baseline ${baseline_performance}ms"
        echo "success"
        return 0
    fi
}

# Helper functions (simplified implementations)
validate_service_data() { return 0; }
create_service_backup() { return 0; }
simulate_data_migration() { return 0; }
start_target_service() { return 0; }
test_service_functionality() { return 0; }
verify_data_integrity() { return 0; }
test_service_endpoints() { return 0; }
create_performance_baseline() { return 0; }
measure_service_performance() { echo "500"; }

# Main execution function
main() {
    local action=${1:-"help"}
    
    case $action in
        "setup")
            setup_staging_environment
            ;;
        "create-test-data")
            local data_type=${2:-"database"}
            local size_mb=${3:-10}
            create_test_data "$data_type" "$size_mb"
            ;;
        "test-migration")
            local test_name=${2:-"default_test"}
            local source=${3:-"source_service"}
            local target=${4:-"target_service"}
            setup_staging_environment
            run_migration_test "$test_name" "$source" "$target"
            ;;
        "cleanup")
            cleanup_staging
            ;;
        "help"|*)
            cat << EOF
Migration Testing Framework

Usage: $0 <action> [options]

Actions:
  setup                           - Setup staging environment
  create-test-data <type> <size>  - Create test data (database|files|images|documents)
  test-migration <name> <src> <dst> - Run migration test
  cleanup                         - Clean up staging environment
  help                           - Show this help

Examples:
  $0 setup
  $0 create-test-data database 100
  $0 test-migration "immich_test" "immich_old" "immich_new"
  $0 cleanup
EOF
            ;;
    esac
}

# Register cleanup functions
register_cleanup cleanup_staging
register_rollback rollback_staging

# Execute main function
main "$@"