package config

import (
	"os"
	"path/filepath"
)

const (
	defaultWorkspaceRoot  = "/workspace"
	defaultDataDirName    = "data"
	defaultDatabaseFile   = "go-crm.db"
	defaultWhatsAppStore  = "whatsapp.db"
	defaultHTTPEndpoint   = "http://localhost:8080"
	defaultInternalSecret = "internal-secret"
)

// WorkspaceRoot returns the path to the shared workspace. CRM_WORKSPACE_PATH overrides it.
// When no override is provided, we try to detect the workspace by walking up from the current
// working directory and looking for the typical monorepo layout. If that fails, we fall back
// to `../..` relative to the current directory and ultimately to `/workspace`.
func WorkspaceRoot() string {
	if v := os.Getenv("CRM_WORKSPACE_PATH"); v != "" {
		return filepath.Clean(v)
	}
	if candidate := detectWorkspaceRoot(); candidate != "" {
		return candidate
	}
	if fallback := fallbackWorkspaceRoot(); fallback != "" {
		return fallback
	}
	return defaultWorkspaceRoot
}

func detectWorkspaceRoot() string {
	wd, err := os.Getwd()
	if err != nil {
		return ""
	}
	for dir := wd; ; {
		if hasDir(dir, "data") && hasDir(dir, "apps") {
			return filepath.Clean(dir)
		}
		parent := filepath.Dir(dir)
		if parent == dir {
			break
		}
		dir = parent
	}
	return ""
}

func fallbackWorkspaceRoot() string {
	wd, err := os.Getwd()
	if err != nil {
		return ""
	}
	return filepath.Clean(filepath.Join(wd, "..", ".."))
}

func hasDir(dir, name string) bool {
	info, err := os.Stat(filepath.Join(dir, name))
	return err == nil && info.IsDir()
}

// DataDir returns the directory that stores SQLite files and related state. CRM_DATA_DIR overrides it.
// If a local ".dev-data" directory exists (for junior-friendly dev), it is preferred.
func DataDir() string {
	if v := os.Getenv("CRM_DATA_DIR"); v != "" {
		return filepath.Clean(v)
	}
	// prefer local .dev-data directory if present
	if cwd, err := os.Getwd(); err == nil {
		if info, err := os.Stat(filepath.Join(cwd, ".dev-data")); err == nil && info.IsDir() {
			return filepath.Join(cwd, ".dev-data")
		}
	}
	return filepath.Join(WorkspaceRoot(), defaultDataDirName)
}

// DatabasePath returns the path to the Go CRM SQLite database. CRM_DATABASE_PATH overrides it.
func DatabasePath() string {
	if v := os.Getenv("CRM_DATABASE_PATH"); v != "" {
		return filepath.Clean(v)
	}
	return filepath.Join(DataDir(), defaultDatabaseFile)
}

// WhatsAppStorePath returns the path where the Whatsmeow session DB is stored. CRM_WHATSAPP_STORE_PATH overrides it.
func WhatsAppStorePath() string {
	if v := os.Getenv("CRM_WHATSAPP_STORE_PATH"); v != "" {
		return filepath.Clean(v)
	}
	return filepath.Join(DataDir(), defaultWhatsAppStore)
}

// HTTPServerEndpoint returns the HTTP endpoint used when WhatsApp events need to call back to the Go server.
func HTTPServerEndpoint() string {
	if v := os.Getenv("CRM_HTTP_ENDPOINT"); v != "" {
		return v
	}
	return defaultHTTPEndpoint
}

// InternalSecret returns the internal secret required by the WhatsApp connector.
func InternalSecret() string {
	if v := os.Getenv("CRM_INTERNAL_SECRET"); v != "" {
		return v
	}
	return defaultInternalSecret
}