#!/bin/sh

# Configuration

DB_TYPE="${DB_TYPE:-pyscopg2}"  # Default to PostgreSQL
POSTGRES_DB="${POSTGRES_DB:-matrix}"
POSTGRES_USER="${POSTGRES_USER:-matrix}"
POSTGRES_PASSWORD="${POSTGRES_PASSWORD:-matrix}"
POSTGRES_HOST=matrixpostgres-db
DB_PORT="5432"

SYNAPSE_HOST="${SYNAPSE_SERVER_NAME:-localhost}"
SYNAPSE_PORT="${SYNAPSE_PORT:-8008}"
ADMIN_USERNAME="${ADMIN_USERNAME:-admin}"
ADMIN_PASSWORD="${ADMIN_PASSWORD:-changeme}"
HOMESERVER_URL="${HOMESERVER_URL:-http://$SYNAPSE_HOST:$SYNAPSE_PORT}"

prepare_postgres () {
    if [ -f "/data/homeserver.yaml" ]; then;
        DB_TYPE=$(yq  '.database.name' /data/homeserver.yaml 2>/dev/null )
        if [ "$DB_TYPE" != "psycopg2" ]; then
            echo "Preparing PostgreSQL database..."
            YAML='.server_name = "'$SYNAPSE_HOST'" |
            .database.name = "psycopg2" |
            .database.args.user = "'$POSTGRES_USER'" | 
            .database.args.password = "'$POSTGRES_PASSWORD'" |
            .database.args.database = "'$POSTGRES_DB'" |
            .database.args.host = "'$POSTGRES_HOST'" |
            .database.args.port = "'$DB_PORT'" |
            .database.args.cp_min = 5 |
            .database.args.cp_max = 10'
            yq eval "$YAML" /data/homeserver.yaml > /data/homeserver.yaml.tmp && mv /data/homeserver.yaml.tmp /data/homeserver.yaml
            exit 0
        fi
    fi
}

# Get registration shared secret from template.json
get_registration_secret() {
    if [ -f "/data/homeserver.yaml" ]; then
        SHARED_SECRET=$(yq  '.registration_shared_secret' /data/homeserver.yaml 2>/dev/null)
    fi
}

# Wait for Synapse to be ready
wait_for_synapse() {
    echo "Waiting for Synapse to be ready..."
    local max_attempts=30
    local attempt=1
    
    while [ $attempt -le $max_attempts ]; do
        if curl -s "$HOMESERVER_URL/_matrix/client/versions" >/dev/null 2>&1; then
            echo "Synapse is ready!"
            return 0
        fi
        echo "Attempt $attempt/$max_attempts - Synapse not ready yet..."
        sleep 2
        attempt=$((attempt + 1))
    done
    
    echo "Error: Synapse did not become ready within expected time"
    return 1
}

# Check if any admin users exist using admin API
check_admin_exists() {
    # Try to get a temporary admin token first
    local temp_token=$(get_admin_token)
    
    if [ -n "$temp_token" ]; then
        local response=$(curl -s -X GET \
            "$HOMESERVER_URL/_synapse/admin/v2/users?deactivated=false" \
            -H "Authorization: Bearer $temp_token" 2>/dev/null || echo "")
        
        if echo "$response" | grep -q '"admin": true'; then
            return 0  # Admin exists
        fi
    fi
    
    return 1  # No admin or couldn't check
}

# Get admin token (this requires an existing admin user)
get_admin_token() {
    # This function would need an existing admin to work
    # For initial setup, we'll rely on registration shared secret
    echo ""
}

# Register admin user using shared secret
register_admin_user() {
    local SHARED_SECRET=$1
    
    echo "Registering admin user: $ADMIN_USERNAME"
    
    # Generate registration MAC
    local nonce=$(date +%s)
    local username_lower=$(echo "$ADMIN_USERNAME" | tr '[:upper:]' '[:lower:]')
    
    # Calculate HMAC (simplified - in practice you'd want to use proper HMAC)
    local mac=$(echo -n "${nonce}${username_lower}${ADMIN_PASSWORD}admin" | openssl dgst -sha1 -hmac "$SHARED_SECRET" -binary | base64)
    
    # Register user
    local response=$(curl -s -X POST "$HOMESERVER_URL/_synapse/admin/v1/register" \
        -H "Content-Type: application/json" \
        -d "{
            \"nonce\": \"$nonce\",
            \"username\": \"$username_lower\",
            \"password\": \"$ADMIN_PASSWORD\",
            \"admin\": true,
            \"mac\": \"$mac\"
        }" 2>/dev/null)
    
    if echo "$response" | grep -q "access_token"; then
        echo "Admin user created successfully!"
        return 0
    else
        echo "Failed to create admin user. Response: $response"
        return 1
    fi
}

# Alternative method using registration endpoint
register_user_simple() {
    local SHARED_SECRET=$1
    
    echo "Attempting simple registration for: $ADMIN_USERNAME"
    
    # Try the simpler registration method
    local response=$(curl -s -X POST "$HOMESERVER_URL/_matrix/client/r0/admin/register" \
        -H "Content-Type: application/json" \
        -d "{
            \"username\": \"$ADMIN_USERNAME\",
            \"password\": \"$ADMIN_PASSWORD\",
            \"admin\": true,
            \"shared_secret\": \"$SHARED_SECRET\"
        }" 2>/dev/null)
    
    echo "Registration response: $response"
}

# Check if admin exists by trying to login
check_admin_by_login() {
    local response=$(curl -s -X POST "$HOMESERVER_URL/_matrix/client/r0/login" \
        -H "Content-Type: application/json" \
        -d "{
            \"type\": \"m.login.password\",
            \"user\": \"$ADMIN_USERNAME\",
            \"password\": \"$ADMIN_PASSWORD\"
        }" 2>/dev/null)
    
    if echo "$response" | grep -q "access_token"; then
        return 0  # User exists and password is correct
    fi
    return 1  # User doesn't exist or wrong password
}

# Main execution
main() {
    echo "Starting Synapse admin initialization..."
    
    if ! wait_for_synapse; then
        exit 1
    fi
    
    # Get registration shared secret
    local SHARED_SECRET=$(get_registration_secret)
    if [ -z "$SHARED_SECRET" ]; then
        echo "Error: Could not find registration_shared_secret"
        echo "Make sure template.json contains the encoded configuration"
        exit 1
    fi
    
    echo "Found registration shared secret"
    
    # Check if admin already exists by trying to login
    if check_admin_by_login; then
        echo "Admin user '$ADMIN_USERNAME' already exists and is accessible"
        exit 0
    fi
    
    echo "No accessible admin user found. Creating admin user..."
    
    # Try to register admin user
    if ! register_admin_user "$SHARED_SECRET"; then
        echo "Primary registration method failed, trying alternative..."
        register_user_simple "$SHARED_SECRET"
    fi
}

# Validate environment
if [ -z "$ADMIN_PASSWORD" ] || [ "$ADMIN_PASSWORD" = "changeme" ]; then
    echo "Warning: Please set a secure ADMIN_PASSWORD"
fi

prepare_postgres

main "$@"