package components

import (
	"fmt"

	"github.com/maxence-charriere/go-app/v9/pkg/app"
	"github.com/mlctrez/goapp-mdc/pkg/base"
	"go.mills.io/saltyim/internal/pwa/storage"
	"go.yarn.social/lextwt"
)

type ChatBox struct {
	app.Compo
	base.JsUtil
	// User is who we're conversing with
	User     string
	messages []string
}

func (c *ChatBox) OnMount(ctx app.Context) {
	ctx.Handle("chatbox", c.actionHandler)
	if c.User != "" {
		c.messages = storage.ConversationsLocalStorage(ctx, c.User).Read()
	}
	ctx.Defer(func(context app.Context) {
		c.Update()
		c.scrollChatPane(ctx)
	})
}

// actionHandler receives messages intended to update this component
func (c *ChatBox) actionHandler(ctx app.Context, action app.Action) {
	c.User = action.Tags.Get("user")
	c.messages = storage.ConversationsLocalStorage(ctx, c.User).Read()
	c.Update()
}

func (c *ChatBox) UpdateMessages(ctx app.Context) {
	if c.User == "" {
		return
	}
	ctx.NewAction("chatbox", app.T("user", c.User))
	c.scrollChatPane(ctx)
}

func (c *ChatBox) Render() app.UI {
	return app.Div().ID("chatbox").Body(c.body())
}

func (c *ChatBox) body() app.UI {
	if c.User == "" {
		return app.P().Text("no user selected to chat with")
	}
	if len(c.messages) == 0 {
		return app.P().Text(fmt.Sprintf("no messages for user = %q", c.User))
	} else {
		return app.Range(c.messages).Slice(func(i int) app.UI {
			s, err := lextwt.ParseSalty(c.messages[i])
			if err != nil {
				app.P().Class("chat-paragraph").Text(c.messages[i])
			}
			switch sc := s.(type) {
			case *lextwt.SaltyText:
				self := !(sc.User.String() == c.User)
				return &ChatMessage{Self: self, Message: sc}
			default:
				return nil
			}
		})
	}
}

func (c *ChatBox) OnResize(ctx app.Context) {
	c.scrollChatPane(ctx)
}

func (c *ChatBox) scrollChatPane(ctx app.Context) {
	ctx.Defer(func(context app.Context) {
		chatBoxDiv := c.JsUtil.JsValueAtPath("chatbox")
		chatBoxDiv.Set("scrollTop", chatBoxDiv.Get("scrollHeight"))
	})
}