package page

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

// 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,
	path string, vars map[string]interface{}, statusCode int) {
	u := getURLPath(r)

	u = filepath.Join(".", u)

	// 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, r, "Not found", http.StatusNotFound)

			return
		}

		Logger.Printf("%s %s path: %s rendering encountered: %s",
			r.RemoteAddr,
			r.Method,
			u,
			err)
		renderJsonErr(w, r, "Internal server error",
			http.StatusInternalServerError)

		return
	}

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

	if r.URL.Query().Get("markdown") == "1" {
		// 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 {
		Logger.Printf("%s %s %d %s: while writing buf: %s",
			r.RemoteAddr,
			r.Method,
			statusCode,
			u,
			err)

		return
	}

	Logger.Printf("%s %s %d %s", r.RemoteAddr, r.Method, statusCode, u)
}

func renderJsonErr(w http.ResponseWriter, r *http.Request, msg string,
	statusCode int) {
	enc := json.NewEncoder(w)
	w.WriteHeader(statusCode)
	_ = enc.Encode(&struct {
		Status string
	}{
		Status: msg,
	})
}