// Copyright 2019 The Hugo Authors. 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 markup_config

import (
	"github.com/gohugoio/hugo/config"
	"github.com/gohugoio/hugo/docshelper"
	"github.com/gohugoio/hugo/markup/blackfriday/blackfriday_config"
	"github.com/gohugoio/hugo/markup/goldmark/goldmark_config"
	"github.com/gohugoio/hugo/markup/highlight"
	"github.com/gohugoio/hugo/markup/tableofcontents"
	"github.com/gohugoio/hugo/parser"
	"github.com/mitchellh/mapstructure"
)

type Config struct {
	// Default markdown handler for md/markdown extensions.
	// Default is "goldmark".
	// Before Hugo 0.60 this was "blackfriday".
	DefaultMarkdownHandler string

	Highlight       highlight.Config
	TableOfContents tableofcontents.Config

	// Content renderers
	Goldmark    goldmark_config.Config
	BlackFriday blackfriday_config.Config
}

func Decode(cfg config.Provider) (conf Config, err error) {
	conf = Default

	m := cfg.GetStringMap("markup")
	if m == nil {
		return
	}

	err = mapstructure.WeakDecode(m, &conf)
	if err != nil {
		return
	}

	if err = applyLegacyConfig(cfg, &conf); err != nil {
		return
	}

	if err = highlight.ApplyLegacyConfig(cfg, &conf.Highlight); err != nil {
		return
	}

	return
}

func applyLegacyConfig(cfg config.Provider, conf *Config) error {
	if bm := cfg.GetStringMap("blackfriday"); bm != nil {
		// Legacy top level blackfriday config.
		err := mapstructure.WeakDecode(bm, &conf.BlackFriday)
		if err != nil {
			return err
		}
	}

	if conf.BlackFriday.FootnoteAnchorPrefix == "" {
		conf.BlackFriday.FootnoteAnchorPrefix = cfg.GetString("footnoteAnchorPrefix")
	}

	if conf.BlackFriday.FootnoteReturnLinkContents == "" {
		conf.BlackFriday.FootnoteReturnLinkContents = cfg.GetString("footnoteReturnLinkContents")
	}

	return nil

}

var Default = Config{
	DefaultMarkdownHandler: "goldmark",

	TableOfContents: tableofcontents.DefaultConfig,
	Highlight:       highlight.DefaultConfig,

	Goldmark:    goldmark_config.Default,
	BlackFriday: blackfriday_config.Default,
}

func init() {
	docsProvider := func() map[string]interface{} {
		docs := make(map[string]interface{})
		docs["markup"] = parser.LowerCaseCamelJSONMarshaller{Value: Default}
		return docs

	}
	// TODO(bep) merge maps
	docshelper.AddDocProvider("config", docsProvider)
}
