package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/charmbracelet/glamour"
)

// renderMarkdown renders markdown text to styled terminal output at the given width.
func renderMarkdown(text string, width int) string {
	if width < 20 {
		width = 20
	}
	r, err := glamour.NewTermRenderer(
		glamour.WithStandardStyle("dracula"),
		glamour.WithWordWrap(width),
	)
	if err != nil {
		return text
	}
	out, err := r.Render(text)
	if err != nil {
		return text
	}
	// Glamour adds leading/trailing newlines — trim them
	return strings.Trim(out, "\n")
}

// renderEvent converts an Event into display lines for the viewport.
func renderEvent(e *Event, agentColorIdx int, showTokens bool, width int) []string {
	timeStr := dimStyle.Render(e.parsed.time.Format("15:04:05"))
	agentTag := agentStyle(agentColorIdx).Render(e.AgentID[:min(7, len(e.AgentID))])

	// Max width for detail text (account for timestamp + agent + icon + padding)
	detailWidth := width - 30
	if detailWidth < 40 {
		detailWidth = 40
	}

	switch e.Type {
	case "user":
		return renderUserEvent(e, timeStr, agentTag, agentColorIdx, detailWidth)
	case "assistant":
		return renderAssistantEvent(e, timeStr, agentTag, agentColorIdx, showTokens, detailWidth)
	case "progress":
		// Hidden by default — could add toggle later
		return nil
	}
	return nil
}

func renderUserEvent(e *Event, timeStr, agentTag string, colorIdx int, detailWidth int) []string {
	var msg messageEnvelope
	if err := json.Unmarshal(e.Message, &msg); err != nil {
		return nil
	}

	// Continuation line prefix: spaces to align under the detail text
	contPrefix := "  " + strings.Repeat(" ", 8+2+7+2+8) + " "

	// Try as string first (teammate message or user text)
	var contentStr string
	if err := json.Unmarshal(msg.Content, &contentStr); err == nil {
		if strings.Contains(contentStr, "<teammate-message") {
			summary := extractTeammateSummary(contentStr)
			wrapped := wrapText(summary, detailWidth, contPrefix)
			lines := []string{
				fmt.Sprintf("  %s  %s  %s %s",
					timeStr, agentTag,
					taskStyle.Render("← TASK:"),
					wrapped[0]),
			}
			for _, cont := range wrapped[1:] {
				lines = append(lines, contPrefix+cont)
			}
			return lines
		}
		wrapped := wrapText(contentStr, detailWidth, contPrefix)
		lines := []string{
			fmt.Sprintf("  %s  %s  %s %s",
				timeStr, agentTag,
				taskStyle.Render("← user:"),
				wrapped[0]),
		}
		for _, cont := range wrapped[1:] {
			lines = append(lines, contPrefix+cont)
		}
		return lines
	}

	// Tool results — skip, they're noise
	return nil
}

func renderAssistantEvent(e *Event, timeStr, agentTag string, colorIdx int, showTokens bool, detailWidth int) []string {
	var msg messageEnvelope
	if err := json.Unmarshal(e.Message, &msg); err != nil {
		return nil
	}

	var blocks []contentBlock
	if err := json.Unmarshal(msg.Content, &blocks); err != nil {
		return nil
	}

	// Continuation line prefix: spaces to align under the detail text
	contPrefix := "  " + strings.Repeat(" ", 8+2+7+2+4) + " "

	var lines []string
	for _, b := range blocks {
		switch b.Type {
		case "text":
			text := strings.TrimSpace(b.Text)
			if text == "" {
				continue
			}

			// Render markdown with glamour
			rendered := renderMarkdown(text, detailWidth)
			mdLines := strings.Split(rendered, "\n")

			// First line gets the header (timestamp + agent + icon)
			header := fmt.Sprintf("  %s  %s  %s ",
				timeStr, agentTag,
				textStyle.Render("▪"))
			if len(mdLines) > 0 {
				lines = append(lines, header+mdLines[0])
			}
			for _, ml := range mdLines[1:] {
				lines = append(lines, contPrefix+ml)
			}

		case "tool_use":
			icon := toolIcon(b.Name)
			detail := getToolDetail(b.Name, b.Input)
			detailStr := ""
			var contLines []string
			if detail != "" {
				toolDetailWidth := detailWidth - len(b.Name) - 5
				wrapped := wrapText(detail, toolDetailWidth, contPrefix)
				detailStr = " " + dimStyle.Render(wrapped[0])
				for _, cont := range wrapped[1:] {
					contLines = append(contLines, contPrefix+dimStyle.Render(cont))
				}
			}
			lines = append(lines, fmt.Sprintf("  %s  %s  %s%s",
				timeStr, agentTag,
				toolStyle.Render(icon+" "+b.Name),
				detailStr))
			lines = append(lines, contLines...)
		}
	}

	// Token usage
	if showTokens && msg.Usage != nil && msg.Usage.OutputTokens > 0 {
		parts := []string{}
		if msg.Usage.OutputTokens > 0 {
			parts = append(parts, fmt.Sprintf("out:%d", msg.Usage.OutputTokens))
		}
		if msg.Usage.CacheReadInputTokens > 0 {
			parts = append(parts, fmt.Sprintf("cache_r:%d", msg.Usage.CacheReadInputTokens))
		}
		if msg.Usage.CacheCreationInputTokens > 0 {
			parts = append(parts, fmt.Sprintf("cache_w:%d", msg.Usage.CacheCreationInputTokens))
		}
		if len(parts) > 0 {
			lines = append(lines, fmt.Sprintf("  %s  %s     %s",
				dimStyle.Render("        "),
				agentStyle(colorIdx).Render(e.AgentID[:min(7, len(e.AgentID))]),
				dimStyle.Render("tokens: "+strings.Join(parts, " | "))))
		}
	}

	return lines
}