context.go

// SPDX-FileCopyrightText: 2026 Comcast Cable Communications Management, LLC
// SPDX-License-Identifier: Apache-2.0

package sallust

import (
	"context"

	"go.uber.org/zap"
)

// contextKey is the internal key type used to access a zap.Logger
// within a context.Context instance
type contextKey struct{}

// defaultLogger is used when no logger exists in the context
var defaultLogger *zap.Logger = zap.NewNop()

// Default returns the default zap.Logger used when no logger is
// found in a context.
func Default() *zap.Logger {
	return defaultLogger
}

// With places a zap.Logger into the context.  If the given logger is nil,
// this function returns the parent as-is.  Since the Get functions return
// a nop logger when there is no logger in the context, a nil logger
// can be safely ignored.
//
// See: https://pkg.go.dev/go.uber.org/zap?tab=doc#Logger
func With(parent context.Context, logger *zap.Logger) context.Context {
	if logger != nil {
		return context.WithValue(parent, contextKey{}, logger)
	}

	return parent
}

// Get returns the zap.Logger from the given context.  If no zap.Logger
// exists, this function returns Default().
//
// See: https://pkg.go.dev/go.uber.org/zap?tab=doc#Logger
// See: https://pkg.go.dev/go.uber.org/zap?tab=doc#NewNop
func Get(ctx context.Context) *zap.Logger {
	if l, ok := ctx.Value(contextKey{}).(*zap.Logger); ok {
		return l
	}

	return Default()
}

// GetDefault attempts to find a zap.Logger in the given context.  If none is
// found, the given default is returned.  If the given default is nil, then
// Default() is returned instead.
//
// See: https://pkg.go.dev/go.uber.org/zap?tab=doc#Logger
func GetDefault(ctx context.Context, def *zap.Logger) *zap.Logger {
	if l, ok := ctx.Value(contextKey{}).(*zap.Logger); ok {
		return l
	}

	if def != nil {
		return def
	}

	return Default()
}