// Copyright or © or Copr. happyDNS (2020)
//
// contact@happydns.org
//
// This software is a computer program whose purpose is to provide a modern
// interface to interact with DNS systems.
//
// This software is governed by the CeCILL license under French law and abiding
// by the rules of distribution of free software.  You can use, modify and/or
// redistribute the software under the terms of the CeCILL license as
// circulated by CEA, CNRS and INRIA at the following URL
// "http://www.cecill.info".
//
// As a counterpart to the access to the source code and rights to copy, modify
// and redistribute granted by the license, users are provided only with a
// limited warranty and the software's author, the holder of the economic
// rights, and the successive licensors have only limited liability.
//
// In this respect, the user's attention is drawn to the risks associated with
// loading, using, modifying and/or developing or reproducing the software by
// the user in light of its specific status of free software, that may mean
// that it is complicated to manipulate, and that also therefore means that it
// is reserved for developers and experienced professionals having in-depth
// computer knowledge. Users are therefore encouraged to load and test the
// software's suitability as regards their requirements in conditions enabling
// the security of their systems and/or data to be ensured and, more generally,
// to use and operate it in the same conditions as regards security.
//
// The fact that you are presently reading this means that you have had
// knowledge of the CeCILL license and that you accept its terms.

package api

import (
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"

	"github.com/miekg/dns"

	"git.happydns.org/happydns/config"
	"git.happydns.org/happydns/model"
	"git.happydns.org/happydns/storage"
)

func init() {
	router.GET("/api/domains", apiAuthHandler(getDomains))
	router.POST("/api/domains", apiAuthHandler(addDomain))

	router.DELETE("/api/domains/:domain", apiAuthHandler(domainHandler(delDomain)))
	router.GET("/api/domains/:domain", apiAuthHandler(domainHandler(getDomain)))

	router.GET("/api/domains/:domain/rr", apiAuthHandler(domainHandler(axfrDomain)))
	router.POST("/api/domains/:domain/rr", apiAuthHandler(domainHandler(addRR)))
	router.DELETE("/api/domains/:domain/rr", apiAuthHandler(domainHandler(delRR)))
}

func getDomains(_ *config.Options, req *RequestResources, body io.Reader) Response {
	if domains, err := storage.MainStore.GetDomains(req.User); err != nil {
		return APIErrorResponse{
			err: err,
		}
	} else if len(domains) > 0 {
		return APIResponse{
			response: domains,
		}
	} else {
		return APIResponse{
			response: []happydns.Domain{},
		}
	}
}

func addDomain(_ *config.Options, req *RequestResources, body io.Reader) Response {
	var uz happydns.Domain
	err := json.NewDecoder(body).Decode(&uz)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	if len(uz.DomainName) <= 2 {
		return APIErrorResponse{
			err: errors.New("The given domain is invalid."),
		}
	}

	uz.DomainName = dns.Fqdn(uz.DomainName)

	if _, ok := dns.IsDomainName(uz.DomainName); !ok {
		return APIErrorResponse{
			err: fmt.Errorf("%q is not a valid domain name.", uz.DomainName),
		}
	}

	source, err := storage.MainStore.GetSource(req.User, uz.IdSource)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	if storage.MainStore.DomainExists(uz.DomainName) {
		return APIErrorResponse{
			err: errors.New("This domain has already been imported."),
		}

	} else if err := source.DomainExists(uz.DomainName); err != nil {
		return APIErrorResponse{
			err: err,
		}
	} else if err := storage.MainStore.CreateDomain(req.User, &uz); err != nil {
		return APIErrorResponse{
			err: err,
		}
	} else {
		return APIResponse{
			response: uz,
		}
	}
}

func delDomain(_ *config.Options, req *RequestResources, body io.Reader) Response {
	if err := storage.MainStore.DeleteDomain(req.Domain); err != nil {
		return APIErrorResponse{
			err: err,
		}
	} else {
		return APIResponse{
			response: true,
		}
	}
}

func domainHandler(f func(*config.Options, *RequestResources, io.Reader) Response) func(*config.Options, *RequestResources, io.Reader) Response {
	return func(opts *config.Options, req *RequestResources, body io.Reader) Response {
		var err error
		if req.Domain, err = storage.MainStore.GetDomainByDN(req.User, req.Ps.ByName("domain")); err != nil {
			return APIErrorResponse{
				status: http.StatusNotFound,
				err:    errors.New("Domain not found"),
			}
		} else {
			return f(opts, req, body)
		}
	}
}

type apiDomain struct {
	Id          int64               `json:"id"`
	IdUser      int64               `json:"id_owner"`
	IdSource    int64               `json:"id_source"`
	DomainName  string              `json:"domain"`
	ZoneHistory []happydns.ZoneMeta `json:"zone_history"`
}

func getDomain(_ *config.Options, req *RequestResources, body io.Reader) Response {
	ret := &apiDomain{
		Id:          req.Domain.Id,
		IdUser:      req.Domain.IdUser,
		IdSource:    req.Domain.IdSource,
		DomainName:  req.Domain.DomainName,
		ZoneHistory: []happydns.ZoneMeta{},
	}

	for _, zm := range req.Domain.ZoneHistory {
		zoneMeta, err := storage.MainStore.GetZoneMeta(zm)

		if err != nil {
			return APIErrorResponse{
				err: err,
			}
		}

		ret.ZoneHistory = append(ret.ZoneHistory, *zoneMeta)
	}

	return APIResponse{
		response: ret,
	}
}

func axfrDomain(opts *config.Options, req *RequestResources, body io.Reader) Response {
	source, err := storage.MainStore.GetSource(req.User, req.Domain.IdSource)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	rrs, err := source.ImportZone(req.Domain)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	var ret []serviceRecord
	for _, rr := range rrs {
		ret = append(ret, serviceRecord{
			String: rr.String(),
			Fields: &rr,
		})
	}

	return APIResponse{
		response: ret,
	}
}

type uploadedRR struct {
	RR string `json:"string"`
}

func addRR(opts *config.Options, req *RequestResources, body io.Reader) Response {
	var urr uploadedRR
	err := json.NewDecoder(body).Decode(&urr)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	rr, err := dns.NewRR(fmt.Sprintf("$ORIGIN %s\n$TTL %d\n%s", req.Domain.DomainName, 3600, urr.RR))
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	source, err := storage.MainStore.GetSource(req.User, req.Domain.IdSource)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	err = source.AddRR(req.Domain, rr)
	if err != nil {
		return APIErrorResponse{
			status: http.StatusInternalServerError,
			err:    err,
		}
	}

	return APIResponse{
		response: serviceRecord{
			String: rr.String(),
			Fields: &rr,
		},
	}
}

func delRR(opts *config.Options, req *RequestResources, body io.Reader) Response {
	var urr uploadedRR
	err := json.NewDecoder(body).Decode(&urr)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	rr, err := dns.NewRR(urr.RR)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	source, err := storage.MainStore.GetSource(req.User, req.Domain.IdSource)
	if err != nil {
		return APIErrorResponse{
			err: err,
		}
	}

	err = source.DeleteRR(req.Domain, rr)
	if err != nil {
		return APIErrorResponse{
			status: http.StatusInternalServerError,
			err:    err,
		}
	}

	return APIResponse{
		response: true,
	}
}