// SPDX-License-Identifier: AGPL-3.0-or-later

//go:build ignore

// chroma-css writes internal/adapters/web/static/css/56-chroma.css: the
// chroma token classes mapped to the --syn-* custom properties of the design
// tokens (the Despair hues, dark and light). Colours are not in the file, so
// the theme follows the colour scheme; only bold and italic come from chroma
// (its "bw" style, as in the mockup).
//
//	go run scripts/chroma-css.go > internal/adapters/web/static/css/56-chroma.css
package main

import (
	"fmt"
	"os"
	"sort"
	"strings"

	"github.com/alecthomas/chroma/v2"
	"github.com/alecthomas/chroma/v2/formatters/html"
	"github.com/alecthomas/chroma/v2/styles"
)

// synVar maps a token type to the name of a --syn-* property, "" for none.
func synVar(t chroma.TokenType) string {
	switch {
	case t == chroma.KeywordType, t == chroma.NameClass, t == chroma.NameBuiltin, t == chroma.NameBuiltinPseudo,
		t == chroma.NameException, t == chroma.NameNamespace:
		return "type"
	case t.InCategory(chroma.Keyword):
		return "keyword"
	case t.InSubCategory(chroma.LiteralString):
		return "string"
	case t.InCategory(chroma.Comment):
		return "comment"
	case t.InSubCategory(chroma.LiteralNumber):
		return "number"
	case t.InSubCategory(chroma.NameFunction), t == chroma.NameDecorator:
		return "func"
	case t.InCategory(chroma.Punctuation), t.InCategory(chroma.Operator):
		return "punct"
	}
	return ""
}

func main() {
	// Learn the classes chroma emits, so that every one is covered.
	var learned strings.Builder
	if err := html.New(html.WithClasses(true)).WriteCSS(&learned, styles.Get("bw")); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	types := map[string]chroma.TokenType{}
	for t, c := range chroma.StandardTypes {
		if c != "" && t > 0 {
			types[c] = t
		}
	}
	bw := styles.Get("bw")
	var classes []string
	for _, l := range strings.Split(learned.String(), "\n") {
		i := strings.Index(l, ".chroma .")
		if i < 0 {
			continue
		}
		c := l[i+len(".chroma ."):]
		c = c[:strings.IndexAny(c, " {")]
		if t, ok := types[c]; ok && synVar(t) != "" {
			classes = append(classes, c)
		}
	}
	sort.Strings(classes)

	fmt.Println("/* Syntax colours of the code view. Generated by scripts/chroma-css.go from")
	fmt.Println("   chroma's token classes; the colours are the --syn-* properties of")
	fmt.Println("   00-tokens.css (the Despair hues, dark and light), none is defined here. */")
	fmt.Println("@layer components {")
	fmt.Println("  .chroma { color: var(--syn-plain); }")
	for _, c := range classes {
		t := types[c]
		decl := "color: var(--syn-" + synVar(t) + ")"
		e := bw.Get(t)
		if e.Bold == chroma.Yes {
			decl += "; font-weight: bold"
		}
		if e.Italic == chroma.Yes {
			decl += "; font-style: italic"
		}
		fmt.Printf("  .chroma .%s { %s }\n", c, decl)
	}
	fmt.Println("  .chroma .line { display: block; }")
	fmt.Println(`
  /* an invisible character in code, shown instead of applied (Trojan Source) */
  .chroma .ctl {
    color: var(--red); font-weight: bold; font-style: normal; font-size: var(--fs-s);
    outline: 1px solid var(--red); outline-offset: -1px; padding: 0 .25ch;
  }
  .img-view { margin-top: var(--lh); & img { max-width: 100%; height: auto; } }
}`)
}