package web

import (
	"fmt"
	"io"
	"net/http"
	"strings"

	"github.com/owen/vibedns/internal/app"
	"github.com/owen/vibedns/internal/validate"
)

// recordInputFromForm assembles a record from either the type-specific editor
// (field_* inputs) or the advanced raw editor.
func recordInputFromForm(r *http.Request) app.RecordInput {
	enabled := formBool(r, "enabled")
	in := app.RecordInput{
		Name:    formString(r, "name"),
		Type:    formString(r, "type"),
		TTL:     formUint32Ptr(r, "ttl"),
		Enabled: &enabled,
		Comment: formString(r, "comment"),
	}

	if formBool(r, "advanced") {
		// The advanced editor supplies rdata verbatim, and may override the
		// record type with one that has no dedicated editor.
		in.Data = formString(r, "data")
		if t := formString(r, "field_rtype"); t != "" {
			in.Type = t
		}
		if d := formString(r, "field_rdata"); d != "" {
			in.Data = d
		}
		return in
	}

	fields := map[string]string{}
	for key, values := range r.Form {
		if !strings.HasPrefix(key, "field_") || len(values) == 0 {
			continue
		}
		fields[strings.TrimPrefix(key, "field_")] = values[0]
	}
	if len(fields) > 0 {
		in.Fields = fields
	} else {
		in.Data = formString(r, "data")
	}
	return in
}

func (s *Server) handleRecordCreate(w http.ResponseWriter, r *http.Request) error {
	zoneID, err := pathID(r, "id")
	if err != nil {
		return err
	}
	if err := parseForm(r); err != nil {
		return err
	}
	rec, err := s.app.CreateRecord(r.Context(), s.actor(r), zoneID, recordInputFromForm(r))
	if err != nil {
		return err
	}
	setFlash(w, r, "success", fmt.Sprintf("Added %s %s record.", rec.Name, rec.Type))
	s.redirectBack(w, r)
	return nil
}

func (s *Server) handleRecordUpdate(w http.ResponseWriter, r *http.Request) error {
	id, err := pathID(r, "id")
	if err != nil {
		return err
	}
	if err := parseForm(r); err != nil {
		return err
	}
	rec, err := s.app.UpdateRecord(r.Context(), s.actor(r), id, recordInputFromForm(r))
	if err != nil {
		return err
	}
	setFlash(w, r, "success", fmt.Sprintf("Saved %s %s record.", rec.Name, rec.Type))
	s.redirectBack(w, r)
	return nil
}

func (s *Server) handleRecordDelete(w http.ResponseWriter, r *http.Request) error {
	id, err := pathID(r, "id")
	if err != nil {
		return err
	}
	if err := parseForm(r); err != nil {
		return err
	}
	if err := s.app.DeleteRecord(r.Context(), s.actor(r), id); err != nil {
		return err
	}
	setFlash(w, r, "success", "Record deleted.")
	s.redirectBack(w, r)
	return nil
}

func (s *Server) handleRecordToggle(w http.ResponseWriter, r *http.Request) error {
	id, err := pathID(r, "id")
	if err != nil {
		return err
	}
	if err := parseForm(r); err != nil {
		return err
	}
	enabled := formBool(r, "enabled")
	if err := s.app.SetRecordEnabled(r.Context(), s.actor(r), id, enabled); err != nil {
		return err
	}
	state := "disabled"
	if enabled {
		state = "enabled"
	}
	setFlash(w, r, "success", "Record "+state+".")
	s.redirectBack(w, r)
	return nil
}

func (s *Server) handleRecordBulk(w http.ResponseWriter, r *http.Request) error {
	zoneID, err := pathID(r, "id")
	if err != nil {
		return err
	}
	if err := parseForm(r); err != nil {
		return err
	}
	ids := formInt64s(r, "record_id")
	action := app.BulkAction(formString(r, "action"))

	n, err := s.app.BulkRecords(r.Context(), s.actor(r), zoneID, ids, action)
	if err != nil {
		return err
	}
	verb := map[app.BulkAction]string{
		app.BulkDelete:  "deleted",
		app.BulkEnable:  "enabled",
		app.BulkDisable: "disabled",
	}[action]
	setFlash(w, r, "success", fmt.Sprintf("%d record%s %s.", n, plural(n), verb))
	s.redirectBack(w, r)
	return nil
}

func plural(n int) string {
	if n == 1 {
		return ""
	}
	return "s"
}

// recordFieldValues splits a stored record back into editor fields, so an
// existing record opens in its dedicated form rather than as raw rdata.
func recordFieldValues(rtype, data string) map[string]string {
	return validate.SplitRData(rtype, data)
}

// copyLimited copies at most n bytes, reporting an error past the limit.
func copyLimited(dst io.Writer, src io.Reader, n int64) (int64, error) {
	return io.Copy(dst, io.LimitReader(src, n))
}