package page

import (
	"bytes"
	"encoding/json"
	"errors"
	"io/fs"
	"net/http"
)

// RenderJSON is analogous to Render, though it renders the page,
// as a JSON key "content", optionally from the YAML it'll include
// additional keys in the json if specified under the 'pageJson' key.
// E.g.
//
//	---
//	title: Some page
//	description: Some page desc
//	jsonvars:
//	  - includeMeInJSON
//	vars:
//	  notIncluded: some value
//	  includeMeInJSON:
//	    some: arbitrary
//	    data: to
//	    send: down
//	|--
//	My page content, wee!
func RenderJSON(w http.ResponseWriter, r *http.Request, //nolint:funlen
	path string, vars map[string]interface{}, statusCode int) {
	// Sepcifically use the specified path for the page
	p := NewPage(path)

	if vars != nil {
		p.Vars = vars
	}

	out := map[string]interface{}{}
	buf := &bytes.Buffer{}

	err := p.Render(buf)
	if err != nil {
		if errors.Is(err, fs.ErrNotExist) {
			renderJSONErr(w, "Not found", http.StatusNotFound)

			return
		}

		logErr(r, "rendering JSON encountered", err)
		renderJSONErr(w, "Internal server error",
			http.StatusInternalServerError)

		return
	}

	if r.URL.Query().Get("content") == "1" {
		out["Content"] = buf.String()
	}

	if r.URL.Query().Get("markdown") == "1" {
		p.setRenderingMarkdownOnly()
		// Tossing the error, since it would've been revealed above
		md, _ := p.GetMarkdown()
		out["Markdown"] = md
	}

	// Make a "set" of keys
	keys := map[string]struct{}{}
	for _, k := range p.JSONVars {
		keys[k] = struct{}{}
	}

	// And chuck the keys specified into the output
	for k, v := range p.Vars {
		_, ok := keys[k]
		if ok {
			out[k] = v
		}
	}

	w.WriteHeader(statusCode)

	enc := json.NewEncoder(w)
	enc.SetIndent("", "  ")
	enc.SetEscapeHTML(false)

	err = enc.Encode(out)
	if err != nil {
		logErr(r, "while writing to buf", err)

		return
	}

	logReq(r, statusCode)
}

func renderJSONErr(w http.ResponseWriter, msg string, statusCode int) {
	enc := json.NewEncoder(w)
	w.WriteHeader(statusCode)

	_ = enc.Encode(&struct {
		StatusCode int
		Msg        string
	}{
		StatusCode: statusCode,
		Msg:        msg,
	})
}