package internal

import (
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"net/http"
	"strconv"
	"time"

	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
	"github.com/go-chi/cors"
)

type adminHandler struct {
	Cache
	Storage
	*RuleEngine
	h http.Handler
}

func NewAdminHandler(c Cache, s Storage, re *RuleEngine) http.Handler {
	handler := chi.NewRouter()

	a := &adminHandler{
		Cache:      c,
		Storage:    s,
		RuleEngine: re,
		h:          handler,
	}

	handler.Use(middleware.RequestID)
	handler.Use(middleware.RealIP)
	handler.Use(middleware.Logger)
	handler.Use(middleware.AllowContentType("application/json; utf-8"))
	handler.Use(middleware.Timeout(time.Second * 10))

	handler.Use(cors.Handler(cors.Options{
		AllowedOrigins:   []string{"http://*", "https://*"},
		AllowedMethods:   []string{"GET", "PUT", "DELETE", "POST", "OPTIONS"},
		AllowedHeaders:   []string{"Content-Type", "Accept"},
		AllowCredentials: false,
		MaxAge:           300,
	}))

	handler.Use(middleware.Recoverer)

	handler.Route("/api/v1", func(r chi.Router) {
		r.Get("/metrics/log", RestHandler(a.getLog).ToHF())
		r.Get("/metrics/stats", RestHandler(a.getStats).ToHF())
		// r.Delete("/cache/purgeall", RestHandler(a.purgeAll).ToHF())
		// r.Delete("/cache/purge", a.purgeKey)
		// r.Get("/cache", a.getCacheContents)
		// r.Put("/rules", a.createRule)
		// r.Get("/rules", a.getRules)
		// r.Delete("/rules/{id}", a.deleteRole)
		// r.Put("/rules/lists", a.addRulelist)
		// r.Get("/rules/lists", a.getRuleLists)
		// r.Delete("/rules/lists/{id}", a.deleteRuleList)
		// r.Post("/rules/lists/reload", a.reloadRuleLists)
	})

	return a

}

func (a *adminHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	a.h.ServeHTTP(w, r)
}

func (a *adminHandler) getStats(r *http.Request) (*RestResponse, error) {
	q := r.URL.Query()
	startFilter := q.Get("start")
	endFilter := q.Get("end")
	key := q.Get("key")
	intervalSecondsStr := q.Get("interval")

	var err error
	start := time.Now().UTC().Add(time.Hour * -86400)
	end := time.Now().UTC()

	if startFilter != "" {
		if start, err = time.Parse(ISO8601, startFilter); err != nil {
			return nil, err
		}
	}

	if endFilter != "" {
		if end, err = time.Parse(ISO8601, endFilter); err != nil {
			return nil, err
		}
	}

	lai := LogAggregateInput{
		Start:  start,
		End:    end,
		Column: key,
	}

	if intervalSecondsStr != "" {
		if lai.IntervalSeconds, err = strconv.Atoi(intervalSecondsStr); err != nil {
			return nil, errors.New("interval query param must be a valid whole number")
		}
	}

	la, err := a.Storage.GetLogAggregate(lai)
	if err != nil {
		return nil, err
	}

	return &RestResponse{
		Status: http.StatusOK,
		Payload: struct {
			Success bool        `json:"success"`
			Payload interface{} `json:"payload"`
		}{
			Success: true,
			Payload: la,
		},
	}, nil

}

func (a *adminHandler) getLog(r *http.Request) (*RestResponse, error) {
	q := r.URL.Query()
	startFilter := q.Get("start")
	endFilter := q.Get("end")
	// filter := q.Get("filter")
	pageStr := q.Get("page")

	var err error
	var page int
	start := time.Now().UTC().Add(time.Hour * -86400)
	end := time.Now().UTC()

	if startFilter != "" {
		if start, err = time.Parse(ISO8601, startFilter); err != nil {
			return nil, err
		}
	}

	if endFilter != "" {
		if end, err = time.Parse(ISO8601, endFilter); err != nil {
			return nil, err
		}
	}

	if pageStr != "" {
		page, _ = strconv.Atoi(pageStr)
	}

	ql, err := a.Storage.GetLog(GetLogInput{
		Start: start,
		End:   end,
		Limit: 250,
		Page:  page,
	})

	if err != nil {
		return nil, err
	}

	return &RestResponse{
		Status: http.StatusOK,
		Payload: struct {
			Success bool        `json:"success"`
			Payload interface{} `json:"payload"`
		}{
			Success: true,
			Payload: ql,
		},
	}, nil

}

type RestResponse struct {
	Status  int
	Headers http.Header
	Payload struct {
		Success bool        `json:"success"`
		Payload interface{} `json:"payload"`
	}
}

func (rr *RestResponse) Write(w http.ResponseWriter) error {
	if rr.Status != 0 && rr.Status != 200 {
		w.WriteHeader(rr.Status)
	}

	for k, v := range rr.Headers {
		for _, ve := range v {
			w.Header().Add(k, ve)
		}
	}

	e := json.NewEncoder(w)
	e.SetIndent("\n", "\t")

	if err := e.Encode(rr.Payload); err != nil {
		return fmt.Errorf("could not serialize struct for http response: %w", err)
	}

	return nil
}

type RestHandler func(request *http.Request) (*RestResponse, error)

func (rh RestHandler) ToHF() http.HandlerFunc {
	return func(rw http.ResponseWriter, r *http.Request) { rh.ServeHTTP(rw, r) }
}

func (rh RestHandler) Error(e error) *RestResponse {
	return &RestResponse{
		Status: http.StatusInternalServerError,
		Payload: struct {
			Success bool        `json:"success"`
			Payload interface{} `json:"payload"`
		}{
			Success: false,
			Payload: e.Error(),
		},
	}
}

func (r RestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	response, err := r(req)
	if err != nil {
		response = r.Error(err)
	}

	if err := response.Write(w); err != nil {
		log.Printf("Error occurred handling rest response: %v", err)
	}
}