package context

import (
	stdlib_context "context"
	"fmt"
	"sync"
	"time"

	lib "git.sr.ht/~cco/go-scopes"
)

type Context = lib.Context
type ContextState = lib.ContextState
type Services = lib.Services

type context struct {
	cfg      lib.Config
	parent   Context
	children []Context
	state    ContextState
	mailbox  chan lib.Message
}

func (ctx *context) Config() lib.Config {
	return ctx.cfg
}

func (ctx *context) Name() string {
	return ctx.cfg.Name()
}

func (ctx *context) Parent() lib.Context {
	return ctx.parent
}

func (ctx *context) Services() Services {
	return ctx.parent.Services()
}

func (ctx *context) ChildContext(cfg lib.Config) Context {
	cctx := makeCtx(cfg, ctx)
	ctx.children = append(ctx.children, cctx)
	name := cfg.Name()
	if name == "" {
		cfg.SetName(fmt.Sprintf("%s.%d", ctx.Name(), len(ctx.children)))
	} else {
		ctx.Services()[name] = cctx
	}
	return cctx
}

func (ctx *context) State() ContextState {
	return ctx.state
}

func (ctx *context) WithState(state ContextState) Context {
	ctx.state = state
	return ctx
}

func (ctx *context) Mailbox() chan lib.Message {
	return ctx.mailbox
}

func (ctx *context) WaitGroup() *sync.WaitGroup {
	return ctx.parent.WaitGroup()
}

func (ctx *context) Done() <-chan struct{} {
	return ctx.parent.Done()
}

func (ctx *context) Send(msg lib.Message) {
	ctx.Mailbox() <- msg
}

func (ctx *context) Stop() {
	// ctx.Warn("Only application-level service can be stopped
}

func makeCtx(cfg lib.Config, parent Context) *context {
	return &context{
		cfg:     cfg,
		parent:  parent,
		mailbox: make(chan lib.Message, 10),
	}
}

// interface Addressable

func (ctx *context) Cell() Context {
	return ctx
}

func (ctx *context) Address() lib.Address {
	return nil
}

// implement interface context.Context from standard library

func (ctx *context) Deadline() (deadline time.Time, ok bool) {
	return time.Time{}, false
}

func (ctx *context) Err() error {
	select {
	case _, ok := <-ctx.Done():
		if !ok {
			return stdlib_context.Canceled
		}
	default:
		return nil
	}
	return nil
}

func (ctx *context) Value(key interface{}) interface{} {
	return nil
}