package server

import (
	"encoding/json"
	"net/http"
	"strconv"
	"time"

	"status/db"
)

func writeJSON(w http.ResponseWriter, a interface{}) {
	bytes, err := json.Marshal(a)
	if err != nil {
		http.Error(w, "500 Internal Server Error", http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	_, err = w.Write(bytes)
	if err != nil {
		http.Error(w, "500 Internal Server Error", http.StatusInternalServerError)
	}
}

func allStatus(w http.ResponseWriter, req *http.Request) {
	status := getStatus()
	writeJSON(w, status)
}

func dayHistory(w http.ResponseWriter, req *http.Request) {
	keys, ok := req.URL.Query()["service_name"]
	if !ok || len(keys) == 0 || len(keys[0]) < 1 {
		http.Error(w, "`service_name` not provided", http.StatusBadRequest)
		return
	}
	if len(keys) >= 2 {
		http.Error(w, "Only one `service_name` allowed", http.StatusBadRequest)
		return
	}
	service_name := keys[0]
	if !validTarget[service_name] {
		http.Error(w, "Invalid `service_name` requested", http.StatusBadRequest)
		return
	}
	keys, ok = req.URL.Query()["interval"]
	var interval = 5
	if len(keys) >= 2 {
		http.Error(w, "Only one `interval` allowed", http.StatusBadRequest)
		return
	}
	if ok && len(keys) == 1 && len(keys[0]) >= 1 {
		var err error
		interval, err = strconv.Atoi(keys[0])
		if err != nil || interval < 1 || interval > 1440 {
			http.Error(w, "Invalid `interval` provided. Must be integer in [1, 1440]", http.StatusBadRequest)
			return
		}
	}
	if service_name == "all" {
		service_name = ""
	}
	entries := db.GetFromDB(service_name, time.Now().Add(time.Duration(-24)*time.Hour), time.Now())
	if interval == 1 {
		writeJSON(w, entries)
		return
	}
	filteredEntries := make([]db.PingEntry, 0, len(entries)/interval)
	for i := 0; i < len(entries); i += interval {
		filteredEntries = append(filteredEntries, entries[i])
	}
	writeJSON(w, filteredEntries)
}

func weekHistory(w http.ResponseWriter, req *http.Request) {
	history(w, req, 7)
}

func monthHistory(w http.ResponseWriter, req *http.Request) {
	history(w, req, 31)
}

func yearHistory(w http.ResponseWriter, req *http.Request) {
	history(w, req, 366)
}

func history(w http.ResponseWriter, req *http.Request, dayCount int) {
	keys, ok := req.URL.Query()["service_name"]
	if !ok || len(keys) == 0 || len(keys[0]) < 1 {
		http.Error(w, "`service_name` not provided", http.StatusBadRequest)
		return
	}
	if len(keys) >= 2 {
		http.Error(w, "Only one `service_name` allowed", http.StatusBadRequest)
		return
	}
	if !validTarget[keys[0]] {
		http.Error(w, "Invalid `service_name` requested", http.StatusBadRequest)
		return
	}
	entries := getHistoryDay(keys[0], dayCount)
	writeJSON(w, entries)
}