package server

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

	"github.com/go-chi/chi/v5"

	"git.wntrmute.dev/mc/mcns/internal/db"
)

type createZoneRequest struct {
	Name       string `json:"name"`
	PrimaryNS  string `json:"primary_ns"`
	AdminEmail string `json:"admin_email"`
	Refresh    int    `json:"refresh"`
	Retry      int    `json:"retry"`
	Expire     int    `json:"expire"`
	MinimumTTL int    `json:"minimum_ttl"`
}

func listZonesHandler(database *db.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, _ *http.Request) {
		zones, err := database.ListZones()
		if err != nil {
			writeError(w, http.StatusInternalServerError, "failed to list zones")
			return
		}
		if zones == nil {
			zones = []db.Zone{}
		}
		writeJSON(w, http.StatusOK, map[string]any{"zones": zones})
	}
}

func getZoneHandler(database *db.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		name := chi.URLParam(r, "zone")
		zone, err := database.GetZone(name)
		if errors.Is(err, db.ErrNotFound) {
			writeError(w, http.StatusNotFound, "zone not found")
			return
		}
		if err != nil {
			writeError(w, http.StatusInternalServerError, "failed to get zone")
			return
		}
		writeJSON(w, http.StatusOK, zone)
	}
}

func createZoneHandler(database *db.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req createZoneRequest
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			writeError(w, http.StatusBadRequest, "invalid request body")
			return
		}

		if req.Name == "" {
			writeError(w, http.StatusBadRequest, "name is required")
			return
		}
		if req.PrimaryNS == "" {
			writeError(w, http.StatusBadRequest, "primary_ns is required")
			return
		}
		if req.AdminEmail == "" {
			writeError(w, http.StatusBadRequest, "admin_email is required")
			return
		}

		// Apply defaults for SOA params.
		req.Refresh, req.Retry, req.Expire, req.MinimumTTL = db.ApplySOADefaults(req.Refresh, req.Retry, req.Expire, req.MinimumTTL)

		zone, err := database.CreateZone(req.Name, req.PrimaryNS, req.AdminEmail, req.Refresh, req.Retry, req.Expire, req.MinimumTTL)
		if errors.Is(err, db.ErrConflict) {
			writeError(w, http.StatusConflict, err.Error())
			return
		}
		if err != nil {
			writeError(w, http.StatusInternalServerError, "failed to create zone")
			return
		}

		writeJSON(w, http.StatusCreated, zone)
	}
}

func updateZoneHandler(database *db.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		name := chi.URLParam(r, "zone")

		var req createZoneRequest
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			writeError(w, http.StatusBadRequest, "invalid request body")
			return
		}

		if req.PrimaryNS == "" {
			writeError(w, http.StatusBadRequest, "primary_ns is required")
			return
		}
		if req.AdminEmail == "" {
			writeError(w, http.StatusBadRequest, "admin_email is required")
			return
		}
		req.Refresh, req.Retry, req.Expire, req.MinimumTTL = db.ApplySOADefaults(req.Refresh, req.Retry, req.Expire, req.MinimumTTL)

		zone, err := database.UpdateZone(name, req.PrimaryNS, req.AdminEmail, req.Refresh, req.Retry, req.Expire, req.MinimumTTL)
		if errors.Is(err, db.ErrNotFound) {
			writeError(w, http.StatusNotFound, "zone not found")
			return
		}
		if err != nil {
			writeError(w, http.StatusInternalServerError, "failed to update zone")
			return
		}

		writeJSON(w, http.StatusOK, zone)
	}
}

func deleteZoneHandler(database *db.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		name := chi.URLParam(r, "zone")

		err := database.DeleteZone(name)
		if errors.Is(err, db.ErrNotFound) {
			writeError(w, http.StatusNotFound, "zone not found")
			return
		}
		if err != nil {
			writeError(w, http.StatusInternalServerError, "failed to delete zone")
			return
		}

		w.WriteHeader(http.StatusNoContent)
	}
}