// reaction_viewer.go implements the reaction details popup overlay.
// Opened with the view_reactions keybind (v), it fetches and displays
// which users reacted with each emoji on the selected message.
package chat

import (
	"fmt"

	"github.com/ayn2op/tview"
	"github.com/diamondburned/arikawa/v3/discord"
	"github.com/gdamore/tcell/v3"
)

const reactionViewerLayerName = "reactionViewer"

func (ml *messagesList) showReactionViewer() {
	msg, err := ml.selectedMessage()
	if err != nil || len(msg.Reactions) == 0 {
		return
	}

	channelID := msg.ChannelID

	var lines []tview.Line
	boldStyle := tcell.StyleDefault.Bold(true)
	dimStyle := tcell.StyleDefault.Dim(true)
	normalStyle := tcell.StyleDefault

	for i, r := range msg.Reactions {
		if i > 0 {
			// Blank separator line
			b := tview.NewLineBuilder()
			b.Write("", normalStyle)
			lines = append(lines, b.Finish()...)
		}

		// Emoji header: "👍 (3)"
		name := r.Emoji.Name
		if r.Emoji.ID.IsValid() && name != "" {
			name = ":" + name + ":"
		}

		b := tview.NewLineBuilder()
		b.Write(fmt.Sprintf("%s (%d)", name, r.Count), boldStyle)
		lines = append(lines, b.Finish()...)

		// Fetch users who reacted
		apiEmoji := discord.NewAPIEmoji(r.Emoji.ID, r.Emoji.Name)
		users, err := ml.chatView.state.Reactions(channelID, msg.ID, apiEmoji, 100)
		if err != nil {
			b = tview.NewLineBuilder()
			b.Write("  (could not load)", dimStyle)
			lines = append(lines, b.Finish()...)
			continue
		}

		for _, u := range users {
			b = tview.NewLineBuilder()
			b.Write("  "+u.DisplayOrUsername(), normalStyle)
			lines = append(lines, b.Finish()...)
		}
	}

	tv := tview.NewTextView().
		SetWrap(true).
		SetWordWrap(true).
		SetLines(lines)
	tv.SetTitle("Reactions")

	ml.chatView.showReactionViewerOverlay(tv)
}