package config

import (
	"errors"
	"fmt"
	"runtime"
	"strconv"
	"strings"

	luajit "git.sharkk.net/Sky/LuaJIT-to-Go"
)

// Config represents a configuration loaded from a Lua file
type Config struct {
	// Server settings
	Server struct {
		Port        int
		Debug       bool
		LogLevel    string
		HTTPLogging bool
	}

	// Runner settings
	Runner struct {
		PoolSize int
	}

	// Directory paths
	Dirs struct {
		Routes   string
		Static   string
		FS       string
		Data     string
		Override string
		Libs     []string
	}

	// Raw values map for custom values
	values map[string]any
}

// New creates a new configuration with default values
func New() *Config {
	config := &Config{
		// Initialize values map
		values: make(map[string]any),
	}

	// Server defaults
	config.Server.Port = 3117
	config.Server.Debug = false
	config.Server.LogLevel = "info"
	config.Server.HTTPLogging = false

	// Runner defaults
	config.Runner.PoolSize = runtime.GOMAXPROCS(0)

	// Dirs defaults
	config.Dirs.Routes = "./routes"
	config.Dirs.Static = "./static"
	config.Dirs.FS = "./fs"
	config.Dirs.Data = "./data"
	config.Dirs.Override = "./override"
	config.Dirs.Libs = []string{"./libs"}

	return config
}

// Load loads configuration from a Lua file
func Load(filePath string) (*Config, error) {
	// Create Lua state
	state := luajit.New(true)
	if state == nil {
		return nil, errors.New("failed to create Lua state")
	}
	defer state.Close()
	defer state.Cleanup()

	// Create config with default values
	config := New()

	// Execute the config file
	if err := state.DoFile(filePath); err != nil {
		return nil, fmt.Errorf("failed to load config file: %w", err)
	}

	// Store values directly to the config
	config.values = make(map[string]any)

	// Extract top-level tables
	tables := []string{"server", "runner", "dirs"}
	for _, table := range tables {
		state.GetGlobal(table)
		if state.IsTable(-1) {
			tableMap, err := state.ToTable(-1)
			if err == nil {
				config.values[table] = tableMap
			}
		}
		state.Pop(1)
	}

	// Apply configuration values
	applyConfig(config, config.values)

	return config, nil
}

// applyConfig applies configuration values from the globals map
func applyConfig(config *Config, values map[string]any) {
	// Apply server settings
	if serverTable, ok := values["server"].(map[string]any); ok {
		if v, ok := serverTable["port"].(float64); ok {
			config.Server.Port = int(v)
		}
		if v, ok := serverTable["debug"].(bool); ok {
			config.Server.Debug = v
		}
		if v, ok := serverTable["log_level"].(string); ok {
			config.Server.LogLevel = v
		}
		if v, ok := serverTable["http_logging"].(bool); ok {
			config.Server.HTTPLogging = v
		}
	}

	// Apply runner settings
	if runnerTable, ok := values["runner"].(map[string]any); ok {
		if v, ok := runnerTable["pool_size"].(float64); ok {
			config.Runner.PoolSize = int(v)
		}
	}

	// Apply dirs settings
	if dirsTable, ok := values["dirs"].(map[string]any); ok {
		if v, ok := dirsTable["routes"].(string); ok {
			config.Dirs.Routes = v
		}
		if v, ok := dirsTable["static"].(string); ok {
			config.Dirs.Static = v
		}
		if v, ok := dirsTable["fs"].(string); ok {
			config.Dirs.FS = v
		}
		if v, ok := dirsTable["data"].(string); ok {
			config.Dirs.Data = v
		}
		if v, ok := dirsTable["override"].(string); ok {
			config.Dirs.Override = v
		}

		// Handle libs array
		if libs, ok := dirsTable["libs"]; ok {
			if libsArray := extractStringArray(libs); len(libsArray) > 0 {
				config.Dirs.Libs = libsArray
			}
		}
	}
}

// extractStringArray extracts a string array from a Lua table
func extractStringArray(value any) []string {
	// Direct array case
	if arr, ok := value.([]any); ok {
		result := make([]string, 0, len(arr))
		for _, v := range arr {
			if str, ok := v.(string); ok {
				result = append(result, str)
			}
		}
		return result
	}

	// Map with numeric keys case
	if tableMap, ok := value.(map[string]any); ok {
		result := make([]string, 0, len(tableMap))
		for _, v := range tableMap {
			if str, ok := v.(string); ok {
				result = append(result, str)
			}
		}
		return result
	}

	return nil
}

// GetCustomValue returns any custom configuration value by key
// Key can be a dotted path like "server.port"
func (c *Config) GetCustomValue(key string) any {
	parts := strings.Split(key, ".")

	if len(parts) == 1 {
		return c.values[key]
	}

	current := c.values
	for _, part := range parts[:len(parts)-1] {
		next, ok := current[part].(map[string]any)
		if !ok {
			return nil
		}
		current = next
	}

	return current[parts[len(parts)-1]]
}

// GetCustomString returns a custom string configuration value
func (c *Config) GetCustomString(key string, defaultValue string) string {
	value := c.GetCustomValue(key)
	if value == nil {
		return defaultValue
	}

	// Convert to string
	switch v := value.(type) {
	case string:
		return v
	case float64:
		return fmt.Sprintf("%g", v)
	case int:
		return strconv.Itoa(v)
	case bool:
		if v {
			return "true"
		}
		return "false"
	default:
		return defaultValue
	}
}

// GetCustomInt returns a custom integer configuration value
func (c *Config) GetCustomInt(key string, defaultValue int) int {
	value := c.GetCustomValue(key)
	if value == nil {
		return defaultValue
	}

	// Convert to int
	switch v := value.(type) {
	case int:
		return v
	case float64:
		return int(v)
	case string:
		if i, err := strconv.Atoi(v); err == nil {
			return i
		}
	case bool:
		if v {
			return 1
		}
		return 0
	default:
		return defaultValue
	}

	return defaultValue
}

// GetCustomBool returns a custom boolean configuration value
func (c *Config) GetCustomBool(key string, defaultValue bool) bool {
	value := c.GetCustomValue(key)
	if value == nil {
		return defaultValue
	}

	// Convert to bool
	switch v := value.(type) {
	case bool:
		return v
	case string:
		switch v {
		case "true", "yes", "1":
			return true
		case "false", "no", "0", "":
			return false
		}
	case int:
		return v != 0
	case float64:
		return v != 0
	default:
		return defaultValue
	}

	return defaultValue
}