package mdprint

func parseInline(text string) []Node {
	var nodes []Node
	runes := []rune(text)
	i := 0

	for i < len(runes) {
		rem := string(runes[i:])

		if len(rem) >= 2 && rem[:2] == "**" {
			end := findDelim(runes, i+2, "**")
			if end >= 0 {
				inner := string(runes[i+2 : end])
				nodes = append(nodes, Bold{Content: parseInline(inner)})
				i = end + 2
				continue
			}
			nodes = append(nodes, Text{Text: "**"})
			i += 2
			continue
		}

		if len(rem) >= 1 && rem[:1] == "*" {
			end := findDelim(runes, i+1, "*")
			if end >= 0 {
				inner := string(runes[i+1 : end])
				nodes = append(nodes, Italic{Content: parseInline(inner)})
				i = end + 1
				continue
			}
			nodes = append(nodes, Text{Text: "*"})
			i++
			continue
		}

		if len(rem) >= 1 && rem[:1] == "`" {
			end := findDelim(runes, i+1, "`")
			if end >= 0 {
				nodes = append(nodes, Code{Text: string(runes[i+1 : end])})
				i = end + 1
				continue
			}
			nodes = append(nodes, Text{Text: "`"})
			i++
			continue
		}

		if len(rem) >= 1 && rem[:1] == "[" {
			closeB := findDelim(runes, i+1, "]")
			if closeB >= 0 && closeB+1 < len(runes) && runes[closeB+1] == '(' {
				closeP := findDelim(runes, closeB+2, ")")
				if closeP >= 0 {
					linkText := string(runes[i+1 : closeB])
					url := string(runes[closeB+2 : closeP])
					nodes = append(nodes, Link{Content: parseInline(linkText), URL: url})
					i = closeP + 1
					continue
				}
			}
		}

		textStart := i
		for i < len(runes) {
			ch := string(runes[i])
			if ch == "*" || ch == "`" || ch == "[" {
				break
			}
			if ch == "\\" && i+1 < len(runes) {
				i += 2
				continue
			}
			i++
		}
		if i > textStart {
			nodes = append(nodes, Text{Text: string(runes[textStart:i])})
		}
	}

	return nodes
}

func findDelim(runes []rune, start int, delim string) int {
	for j := start; j < len(runes); j++ {
		rem := string(runes[j:])
		if len(rem) >= len(delim) && rem[:len(delim)] == delim {
			return j
		}
	}
	return -1
}