package config

import (
	"bytes"
	"fmt"
	"log/slog"
	"os/exec"
	"path/filepath"
	"strings"

	"github.com/wild-cloud/wild-central/internal/network"
	"github.com/wild-cloud/wild-central/internal/storage"
)

// YQ provides a wrapper around the yq command-line tool
type YQ struct {
	yqPath string
}

// NewYQ creates a new YQ wrapper
func NewYQ() *YQ {
	path, err := exec.LookPath("yq")
	if err != nil {
		path = "yq"
	}
	return &YQ{yqPath: path}
}

// Get retrieves a value from a YAML file using a yq expression
func (y *YQ) Get(filePath, expression string) (string, error) {
	cmd := exec.Command(y.yqPath, expression, filePath)
	var stdout, stderr bytes.Buffer
	cmd.Stdout = &stdout
	cmd.Stderr = &stderr
	if err := cmd.Run(); err != nil {
		return "", fmt.Errorf("yq get failed: %w, stderr: %s", err, stderr.String())
	}
	return strings.TrimSpace(stdout.String()), nil
}

// Set sets a value in a YAML file using a yq expression
func (y *YQ) Set(filePath, expression, value string) error {
	if !strings.HasPrefix(expression, ".") {
		expression = "." + expression
	}
	quotedValue := fmt.Sprintf(`"%s"`, strings.ReplaceAll(value, `"`, `\"`))
	setExpr := fmt.Sprintf("%s = %s", expression, quotedValue)
	cmd := exec.Command(y.yqPath, "-i", setExpr, filePath)
	var stderr bytes.Buffer
	cmd.Stderr = &stderr
	if err := cmd.Run(); err != nil {
		return fmt.Errorf("yq set failed: %w, stderr: %s", err, stderr.String())
	}
	return nil
}

// Delete removes a key from a YAML file
func (y *YQ) Delete(filePath, expression string) error {
	delExpr := fmt.Sprintf("del(%s)", expression)
	cmd := exec.Command(y.yqPath, "-i", delExpr, filePath)
	var stderr bytes.Buffer
	cmd.Stderr = &stderr
	if err := cmd.Run(); err != nil {
		return fmt.Errorf("yq delete failed: %w, stderr: %s", err, stderr.String())
	}
	return nil
}

// Validate checks if a YAML file is valid
func (y *YQ) Validate(filePath string) error {
	cmd := exec.Command(y.yqPath, "eval", ".", filePath)
	var stderr bytes.Buffer
	cmd.Stderr = &stderr
	if err := cmd.Run(); err != nil {
		return fmt.Errorf("yaml validation failed: %w, stderr: %s", err, stderr.String())
	}
	return nil
}

// Manager handles configuration file operations with idempotency
type Manager struct {
	yq *YQ
}

// NewManager creates a new config manager
func NewManager() *Manager {
	return &Manager{
		yq: NewYQ(),
	}
}

// EnsureGlobalConfig ensures a global config file exists with proper structure
func (m *Manager) EnsureGlobalConfig(dataDir string) error {
	configPath := filepath.Join(dataDir, "config.yaml")

	// Check if config already exists
	if storage.FileExists(configPath) {
		// Validate existing config
		if err := m.yq.Validate(configPath); err != nil {
			return fmt.Errorf("invalid config file: %w", err)
		}
		return nil
	}

	// Create config structure with detected defaults
	initialConfig := &GlobalConfig{}

	// Detect network configuration
	netInfo, err := network.DetectNetworkInfo()
	if err != nil {
		slog.Info("network detection failed, using defaults", "component", "config", "error", err)
	} else {
		// Set detected values
		initialConfig.Cloud.Router.IP = netInfo.Gateway
		slog.Info("detected network", "component", "config", "gateway", netInfo.Gateway, "interface", netInfo.PrimaryInterface)
	}

	// Ensure data directory exists
	if err := storage.EnsureDir(dataDir, 0755); err != nil {
		return err
	}

	// Save config using the model's save function
	return SaveGlobalConfig(initialConfig, configPath)
}

// EnsureInstanceConfig ensures an instance config file exists with proper structure
func (m *Manager) EnsureInstanceConfig(name string, dataDir string) error {
	configPath := filepath.Join(dataDir, "instances", name, "config", "instance.yaml")

	// Check if config already exists
	if storage.FileExists(configPath) {
		// Validate existing config
		if err := m.yq.Validate(configPath); err != nil {
			return fmt.Errorf("invalid config file: %w", err)
		}
		return nil
	}

	// Ensure config directory exists
	if err := storage.EnsureDir(filepath.Join(dataDir, "instances", name, "config"), 0755); err != nil {
		return err
	}

	initialConfig := &InstanceConfig{}
	initialConfig.Cluster.Name = name
	initialConfig.Cluster.Nodes.Active = make(map[string]NodeConfig)
	initialConfig.Apps = make(map[string]any)
	return SaveCloudConfig(initialConfig, configPath)
}

// GetConfigValue retrieves a value from a config file
func (m *Manager) GetConfigValue(configPath, key string) (string, error) {
	if !storage.FileExists(configPath) {
		return "", fmt.Errorf("config file not found: %s", configPath)
	}

	value, err := m.yq.Get(configPath, fmt.Sprintf(".%s", key))
	if err != nil {
		return "", fmt.Errorf("getting config value %s: %w", key, err)
	}

	return value, nil
}

// SetConfigValue sets a value in a config file
func (m *Manager) SetConfigValue(configPath, key, value string) error {
	if !storage.FileExists(configPath) {
		return fmt.Errorf("config file not found: %s", configPath)
	}

	// Acquire lock before modifying
	lockPath := configPath + ".lock"
	return storage.WithLock(lockPath, func() error {
		return m.yq.Set(configPath, fmt.Sprintf(".%s", key), value)
	})
}

// EnsureConfigValue sets a value only if it's not already set (idempotent)
func (m *Manager) EnsureConfigValue(configPath, key, value string) error {
	if !storage.FileExists(configPath) {
		return fmt.Errorf("config file not found: %s", configPath)
	}

	// Check if value already set
	currentValue, err := m.GetConfigValue(configPath, key)
	if err == nil && currentValue != "" && currentValue != "null" {
		// Value already set, skip
		return nil
	}

	// Set the value
	return m.SetConfigValue(configPath, key, value)
}

// ValidateConfig validates a config file
func (m *Manager) ValidateConfig(configPath string) error {
	if !storage.FileExists(configPath) {
		return fmt.Errorf("config file not found: %s", configPath)
	}

	return m.yq.Validate(configPath)
}

// CopyConfig copies a config file to a new location
func (m *Manager) CopyConfig(srcPath, dstPath string) error {
	if !storage.FileExists(srcPath) {
		return fmt.Errorf("source config file not found: %s", srcPath)
	}

	// Read source
	content, err := storage.ReadFile(srcPath)
	if err != nil {
		return err
	}

	// Ensure destination directory exists
	if err := storage.EnsureDir(filepath.Dir(dstPath), 0755); err != nil {
		return err
	}

	// Write destination
	return storage.WriteFile(dstPath, content, 0644)
}

// GetInstanceConfigPath returns the path to an instance's config file
func GetInstanceConfigPath(dataDir, instanceName string) string {
	return filepath.Join(dataDir, "instances", instanceName, "config", "instance.yaml")
}

// GetInstanceSecretsPath returns the path to an instance's secrets file
func GetInstanceSecretsPath(dataDir, instanceName string) string {
	return filepath.Join(dataDir, "instances", instanceName, "config", "secrets.yaml")
}

// GetInstancePath returns the path to an instance directory
func GetInstancePath(dataDir, instanceName string) string {
	return filepath.Join(dataDir, "instances", instanceName)
}