package issue

import (
	"fmt"
	"strings"
	"time"
)

type discussionIssue struct {
	Number    int64
	Title     string
	Author    string
	State     string
	Labels    []string
	Body      string
	CreatedAt time.Time
}

type discussionComment struct {
	Author    string
	CreatedAt time.Time
	Body      string
}

// formatDiscussionMarkdown renders an issue and its comments as a single
// Markdown document suitable for display without further parsing.
func formatDiscussionMarkdown(issue discussionIssue, comments []discussionComment) string {
	var b strings.Builder

	fmt.Fprintf(&b, "# %s (#%d)\n\n", issue.Title, issue.Number)
	fmt.Fprintf(&b, "**Author:** %s\n", issue.Author)
	fmt.Fprintf(&b, "**State:** %s\n", issue.State)
	if len(issue.Labels) > 0 {
		fmt.Fprintf(&b, "**Labels:** %s\n", strings.Join(issue.Labels, ", "))
	}
	if !issue.CreatedAt.IsZero() {
		fmt.Fprintf(&b, "**Created:** %s\n", issue.CreatedAt.UTC().Format(time.RFC3339))
	}
	b.WriteString("\n")
	b.WriteString(strings.TrimSpace(issue.Body))
	b.WriteString("\n\n---\n\n## Comments\n\n")

	if len(comments) == 0 {
		b.WriteString("_No comments yet._\n")
		return b.String()
	}

	for i, c := range comments {
		fmt.Fprintf(&b, "### %s", c.Author)
		if !c.CreatedAt.IsZero() {
			fmt.Fprintf(&b, " on %s", c.CreatedAt.UTC().Format(time.RFC3339))
		}
		b.WriteString("\n\n")
		b.WriteString(strings.TrimSpace(c.Body))
		if i < len(comments)-1 {
			b.WriteString("\n\n---\n\n")
		} else {
			b.WriteString("\n")
		}
	}

	return b.String()
}