package config

import (
	"reflect"
	"regexp"
	"strings"
)

// EnvVar represents an environment variable with its documentation
type EnvVar struct {
	Name        string
	Description string
	Default     string
	HasDefault  bool
	Required    bool
}

// extractEnvVars parses a struct's field comments to extract environment variable documentation
func extractEnvVars(structType reflect.Type, fieldIndex int) *EnvVar {
	field := structType.Field(fieldIndex)
	tag := field.Tag.Get("comment")
	if tag == "" {
		// Try to get the comment from the struct field's tag or use reflection
		// For now, we'll parse it manually from the comment string
		return nil
	}

	comment := tag
	if !strings.HasPrefix(comment, "ENV ") {
		return nil
	}

	// Remove "ENV " prefix
	comment = strings.TrimPrefix(comment, "ENV ")

	// Extract name and description
	parts := strings.SplitN(comment, ":", 2)
	if len(parts) != 2 {
		return nil
	}

	name := strings.TrimSpace(parts[0])
	desc := strings.TrimSpace(parts[1])

	// Check for default value in description
	defaultRegex := regexp.MustCompile(`\(default:\s*([^)]+)\)`)
	matches := defaultRegex.FindStringSubmatch(desc)

	envVar := &EnvVar{
		Name:        name,
		Description: desc,
	}

	if len(matches) > 1 {
		envVar.Default = matches[1]
		envVar.HasDefault = true
		// Remove the default notation from description
		envVar.Description = strings.TrimSpace(defaultRegex.ReplaceAllString(desc, ""))
	}

	return envVar
}

// GetAllEnvVars returns a list of all environment variables used in the config
func GetAllEnvVars() []EnvVar {
	var envVars []EnvVar

	// Manually define all env vars based on the config structs
	// This is more reliable than reflection for extracting comments

	// DBConfig
	envVars = append(envVars, []EnvVar{
		{Name: "DB_USER", Description: "Database user for authentication", HasDefault: false, Required: true},
		{Name: "DB_PASSWORD", Description: "Database password for authentication", HasDefault: false, Required: true},
		{Name: "DB_HOST", Description: "Database host address", HasDefault: false, Required: true},
		{Name: "DB_PORT", Description: "Database port", Default: "5432", HasDefault: true, Required: false},
		{Name: "DB_NAME", Description: "Database name to connect to", HasDefault: false, Required: true},
		{Name: "DB_SSL", Description: "SSL mode for connection", Default: "disable", HasDefault: true, Required: false},
	}...)

	// HWSConfig
	envVars = append(envVars, []EnvVar{
		{Name: "HWS_HOST", Description: "Host to listen on", Default: "127.0.0.1", HasDefault: true, Required: false},
		{Name: "HWS_PORT", Description: "Port to listen on", Default: "3000", HasDefault: true, Required: false},
		{Name: "HWS_TRUSTED_HOST", Description: "Domain/Hostname to accept as trusted", Default: "same as Host", HasDefault: true, Required: false},
		{Name: "HWS_SSL", Description: "Flag for SSL Mode", Default: "false", HasDefault: true, Required: false},
		{Name: "HWS_GZIP", Description: "Flag for GZIP compression on requests", Default: "false", HasDefault: true, Required: false},
		{Name: "HWS_READ_HEADER_TIMEOUT", Description: "Timeout for reading request headers in seconds", Default: "2", HasDefault: true, Required: false},
		{Name: "HWS_WRITE_TIMEOUT", Description: "Timeout for writing requests in seconds", Default: "10", HasDefault: true, Required: false},
		{Name: "HWS_IDLE_TIMEOUT", Description: "Timeout for idle connections in seconds", Default: "120", HasDefault: true, Required: false},
	}...)

	// HWSAUTHConfig
	envVars = append(envVars, []EnvVar{
		{Name: "HWSAUTH_SECRET_KEY", Description: "Secret key for signing tokens", HasDefault: false, Required: true},
		{Name: "HWSAUTH_ACCESS_TOKEN_EXPIRY", Description: "Access token expiry in minutes", Default: "5", HasDefault: true, Required: false},
		{Name: "HWSAUTH_REFRESH_TOKEN_EXPIRY", Description: "Refresh token expiry in minutes", Default: "1440", HasDefault: true, Required: false},
		{Name: "HWSAUTH_TOKEN_FRESH_TIME", Description: "Time for tokens to stay fresh in minutes", Default: "5", HasDefault: true, Required: false},
	}...)

	// TMDBConfig
	envVars = append(envVars, []EnvVar{
		{Name: "TMDB_TOKEN", Description: "API token for TMDB", HasDefault: false, Required: true},
	}...)

	// HLOGConfig
	envVars = append(envVars, []EnvVar{
		{Name: "LOG_LEVEL", Description: "Log level for global logging", Default: "info", HasDefault: true, Required: false},
		{Name: "LOG_OUTPUT", Description: "Output method for the logger (file, console, or both)", Default: "console", HasDefault: true, Required: false},
		{Name: "LOG_DIR", Description: "Path to create log files", HasDefault: false, Required: false},
	}...)

	return envVars
}