package lexers

import (

	. "github.com/alecthomas/chroma/v2" // nolint

)

// Svelte lexer.

var Svelte = Register(DelegatingLexer(HTML, MustNewLexer(

	&Config{

		Name:      "Svelte",

		Aliases:   []string{"svelte"},

		Filenames: []string{"*.svelte"},

		MimeTypes: []string{"application/x-svelte"},

		DotAll:    true,

	},

	svelteRules,

)))

func svelteRules() Rules {

	return Rules{

		"root": {

			// Let HTML handle the comments, including comments containing script and style tags

			{`<!--`, Other, Push("comment")},

			{

				// Highlight script and style tags based on lang attribute

				// and allow attributes besides lang

				`(<\s*(?:script|style).*?lang\s*=\s*['"])` +

					`(.+?)(['"].*?>)` +

					`(.+?)` +

					`(<\s*/\s*(?:script|style)\s*>)`,

				UsingByGroup(2, 4, Other, Other, Other, Other, Other),

				nil,

			},

			{

				// Make sure `{` is not inside script or style tags

				`(?<!<\s*(?:script|style)(?:(?!(?:script|style)\s*>).)*?)` +

					`{` +

					`(?!(?:(?!<\s*(?:script|style)).)*?(?:script|style)\s*>)`,

				Punctuation,

				Push("templates"),

			},

			// on:submit|preventDefault

			{`(?<=\s+on:\w+(?:\|\w+)*)\|(?=\w+)`, Operator, nil},

			{`.+?`, Other, nil},

		},

		"comment": {

			{`-->`, Other, Pop(1)},

			{`.+?`, Other, nil},

		},

		"templates": {

			{`}`, Punctuation, Pop(1)},

			// Let TypeScript handle strings and the curly braces inside them

			{`(?<!(?<!\\)\\)(['"` + "`])" + `.*?(?<!(?<!\\)\\)\1`, Using("TypeScript"), nil},

			// If there is another opening curly brace push to templates again

			{"{", Punctuation, Push("templates")},

			{`@(debug|html)\b`, Keyword, nil},

			{

				`(#await)(\s+)(\w+)(\s+)(then|catch)(\s+)(\w+)`,

				ByGroups(Keyword, Text, Using("TypeScript"), Text,

					Keyword, Text, Using("TypeScript"),

				),

				nil,

			},

			{`(#|/)(await|each|if|key)\b`, Keyword, nil},

			{`(:else)(\s+)(if)?\b`, ByGroups(Keyword, Text, Keyword), nil},

			{`:(catch|then)\b`, Keyword, nil},

			{`[^{}]+`, Using("TypeScript"), nil},

		},

	}

}