// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package driver

import (
	"embed"
	"fmt"
	"html/template"
	"os"

	"github.com/google/pprof/third_party/d3flamegraph"
)

//go:embed html
var embeddedFiles embed.FS

// addTemplates adds a set of template definitions to templates.
func addTemplates(templates *template.Template) {
	// Load specified file.
	loadFile := func(fname string) string {
		data, err := embeddedFiles.ReadFile(fname)
		if err != nil {
			fmt.Fprintf(os.Stderr, "internal/driver: embedded file %q not found\n",
				fname)
			os.Exit(1)
		}
		return string(data)
	}
	loadCSS := func(fname string) string {
		return `<style type="text/css">` + "\n" + loadFile(fname) + `</style>` + "\n"
	}
	loadJS := func(fname string) string {
		return `<script>` + "\n" + loadFile(fname) + `</script>` + "\n"
	}

	// Define a named template with specified contents.
	def := func(name, contents string) {
		sub := template.New(name)
		template.Must(sub.Parse(contents))
		template.Must(templates.AddParseTree(name, sub.Tree))
	}

	// Pre-packaged third-party files.
	def("d3flamegraphscript", d3flamegraph.JSSource)
	def("d3flamegraphcss", d3flamegraph.CSSSource)

	// Embeded files.
	def("css", loadCSS("html/common.css"))
	def("header", loadFile("html/header.html"))
	def("graph", loadFile("html/graph.html"))
	def("script", loadJS("html/common.js"))
	def("top", loadFile("html/top.html"))
	def("sourcelisting", loadFile("html/source.html"))
	def("plaintext", loadFile("html/plaintext.html"))
	def("flamegraph", loadFile("html/flamegraph.html"))
}