package mdprint

import (
	"fmt"
	"strings"

	"hub.gaomia.site/titor/YunShu/pkg/style"
)

func renderNode(node Node) string {
	switch n := node.(type) {
	case Heading:
		return renderHeading(n)
	case Paragraph:
		return renderParagraph(n)
	case CodeBlock:
		return renderCodeBlock(n)
	case Blockquote:
		return renderBlockquote(n)
	case List:
		return renderList(n)
	case Table:
		return renderTable(n)
	case ThematicBreak:
		return "\n" + style.Dim.Render("────────────────────────────") + "\n"
	case Text:
		return style.New().Render(n.Text)
	case Bold:
		return renderBold(n)
	case Italic:
		return renderItalic(n)
	case Code:
		return renderInlineCode(n)
	case Link:
		return renderLink(n)
	default:
		return fmt.Sprintf("%v", n)
	}
}

func renderInline(nodes []Node) string {
	var b strings.Builder
	for _, child := range nodes {
		b.WriteString(renderNode(child))
	}
	return b.String()
}

var headingConfig = []struct {
	symbol string
	style  *style.Style
}{
	{"▪ ", style.New().Bold().FgHex("#6B8E9B")},
	{"▪ ", style.New().Bold().FgHex("#89A894")},
	{"▪ ", style.New().Bold().FgHex("#A6C0B5")},
	{"▫ ", style.New().Bold().FgHex("#C3B1BD")},
	{"▫ ", style.New().Bold().FgHex("#7B8E8A")},
	{"",   style.New().Bold().Dim()},
}

func renderHeading(h Heading) string {
	cfg := headingConfig[0]
	if h.Level-1 < len(headingConfig) {
		cfg = headingConfig[h.Level-1]
	}
	suffix := ""
	if h.Level == 1 {
		suffix = "\n"
	}
	return "\n" + cfg.style.Render(cfg.symbol+renderInline(h.Content)) + suffix
}

func renderParagraph(p Paragraph) string {
	return renderInline(p.Content)
}

func renderCodeBlock(c CodeBlock) string {
	var b strings.Builder
	if c.Lang != "" {
		b.WriteString(style.Dim.Render(c.Lang + " ") + "\n")
	}
	for _, line := range strings.Split(c.Body, "\n") {
		b.WriteString("  " + style.New().Fg(style.ColorYellow).Render(line) + "\n")
	}
	return strings.TrimRight(b.String(), "\n")
}

func renderBlockquote(q Blockquote) string {
	var b strings.Builder
	for i, child := range q.Children {
		if i > 0 {
			b.WriteString("\n")
		}
		rendered := renderNode(child)
		for _, line := range strings.Split(rendered, "\n") {
			b.WriteString(style.Dim.Render("│ ") + line + "\n")
		}
	}
	return strings.TrimRight(b.String(), "\n")
}

func renderList(l List) string {
	var b strings.Builder
	for i, item := range l.Items {
		if i > 0 {
			b.WriteString("\n")
		}
		prefix := "-  "
		if l.Ordered {
			prefix = fmt.Sprintf("%d. ", i+1)
		}
		if item.Checked != nil {
			check := " "
			if *item.Checked {
				check = "x"
			}
			prefix = fmt.Sprintf("- [%s] ", check)
		}
		b.WriteString(style.Dim.Render(prefix) + renderInline(item.Content))
	}
	return b.String()
}

func renderTable(t Table) string {
	if len(t.Headers) == 0 {
		return ""
	}
	var b strings.Builder

	colWidths := make([]int, len(t.Headers))
	for i, h := range t.Headers {
		colWidths[i] = len(h)
	}
	for _, row := range t.Rows {
		for i, cell := range row {
			if i < len(colWidths) && len(cell) > colWidths[i] {
				colWidths[i] = len(cell)
			}
		}
	}

	renderRow := func(cells []string, isHeader bool) {
		b.WriteString("| ")
		for i, cell := range cells {
			if i > 0 {
				b.WriteString(" | ")
			}
			if i < len(colWidths) {
				cell = fmt.Sprintf("%-*s", colWidths[i], cell)
			}
			if isHeader {
				b.WriteString(style.Bold.Render(cell))
			} else {
				b.WriteString(cell)
			}
		}
		b.WriteString(" |")
	}

	renderRow(t.Headers, true)

	sep := "| "
	for i, w := range colWidths {
		if i > 0 {
			sep += " | "
		}
		sep += strings.Repeat("-", w)
	}
	sep += " |"
	b.WriteString("\n" + style.Dim.Render(sep))

	for _, row := range t.Rows {
		b.WriteString("\n")
		renderRow(row, false)
	}

	return b.String()
}

func renderBold(b Bold) string {
	return style.New().Bold().Render(renderInline(b.Content))
}

func renderItalic(i Italic) string {
	return style.New().Italic().Render(renderInline(i.Content))
}

func renderInlineCode(c Code) string {
	return style.New().Fg(style.ColorYellow).Render("`" + c.Text + "`")
}

func renderLink(l Link) string {
	text := renderInline(l.Content)
	url := l.URL
	if text == "" {
		text = url
		url = ""
	}
	styled := style.New().Underline().Fg(style.ColorBlue).Render(text)
	if url != "" {
		styled += style.Dim.Render(" (" + url + ")")
	}
	return styled
}