expr/module-register.go

// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.

// module-register.go
package expr

import (
	"fmt"
	"path/filepath"
)

type module struct {
	importFunc  func(ExprContext)
	description string
	imported    bool
}

func newModule(importFunc func(ExprContext), description string) *module {
	return &module{importFunc, description, false}
}

var moduleRegister map[string]*module

func registerImport(name string, importFunc func(ExprContext), description string) {
	if moduleRegister == nil {
		moduleRegister = make(map[string]*module)
	}
	if _, exists := moduleRegister[name]; exists {
		panic(fmt.Errorf("module %q already registered", name))
	}
	moduleRegister[name] = newModule(importFunc, description)
}

func ImportInContext(ctx ExprContext, name string) (exists bool) {
	var mod *module
	if mod, exists = moduleRegister[name]; exists {
		mod.importFunc(ctx)
		mod.imported = true
	}
	return
}

func ImportInContextByGlobPattern(ctx ExprContext, pattern string) (count int, err error) {
	var matched bool
	for name, mod := range moduleRegister {
		if matched, err = filepath.Match(pattern, name); err == nil {
			if matched {
				count++
				mod.importFunc(ctx)
				mod.imported = true
			}
		} else {
			break
		}
	}
	return
}

func IterateModules(op func(name, description string, imported bool) bool) {
	if op != nil {
		for name, mod := range moduleRegister {
			if !op(name, mod.description, mod.imported) {
				break
			}
		}
	}
}

// ----
func init() {
	if moduleRegister == nil {
		moduleRegister = make(map[string]*module)
	}
}