package main

import (
	"encoding/csv"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"strconv"
	"strings"
)

type coordsResponse []struct {
	Name    string  `json:"name"`
	Lat     float64 `json:"lat"`
	Lon     float64 `json:"lon"`
	Country string  `json:"country"`
	State   string  `json:"state"`
}

type Coords struct {
	Name    string  `json:"name"`
	Lat     float64 `json:"lat"`
	Lon     float64 `json:"lon"`
	Country string  `json:"country"`
	State   string  `json:"state"`
}

type Rain struct {
	Hour float64 `json:"1h"`
}
type Snow struct {
	Hour float64 `json:"1h"`
}

type WeatherResponse struct {
	Lat            float64 `json:"lat"`
	Lon            float64 `json:"lon"`
	Timezone       string  `json:"timezone"`
	TimezoneOffset int     `json:"timezone_offset"`
	Current        struct {
		Dt         int64   `json:"dt"`
		Sunrise    int     `json:"sunrise"`
		Sunset     int     `json:"sunset"`
		Temp       float64 `json:"temp"`
		FeelsLike  float64 `json:"feels_like"`
		Pressure   int     `json:"pressure"`
		Humidity   int     `json:"humidity"`
		DewPoint   float64 `json:"dew_point"`
		Uvi        float64 `json:"uvi"`
		Clouds     int     `json:"clouds"`
		Visibility int     `json:"visibility"`
		WindSpeed  float64 `json:"wind_speed"`
		WindDeg    int     `json:"wind_deg"`
		Rain       *Rain   `json:"rain,omitempty"`
		Snow       *Snow   `json:"snow,omitempty"`
		Weather    []struct {
			ID          int    `json:"id"`
			Main        string `json:"main"`
			Description string `json:"description"`
			Icon        string `json:"icon"`
		} `json:"weather"`
	} `json:"current"`
	Minutely []struct {
		Dt            int64   `json:"dt"`
		Precipitation float64 `json:"precipitation"`
	} `json:"minutely"`
	Hourly []struct {
		Dt         int64   `json:"dt"`
		Temp       float64 `json:"temp"`
		FeelsLike  float64 `json:"feels_like"`
		Pressure   int     `json:"pressure"`
		Humidity   int     `json:"humidity"`
		DewPoint   float64 `json:"dew_point"`
		Uvi        float64 `json:"uvi"`
		Clouds     int     `json:"clouds"`
		Visibility int     `json:"visibility,omitempty"`
		WindSpeed  float64 `json:"wind_speed"`
		WindDeg    int     `json:"wind_deg"`
		WindGust   float64 `json:"wind_gust"`
		Weather    []struct {
			ID          int    `json:"id"`
			Main        string `json:"main"`
			Description string `json:"description"`
			Icon        string `json:"icon"`
		} `json:"weather"`
		Pop  float64 `json:"pop"`
		Rain *Rain   `json:"rain,omitempty"`
		Snow *Snow   `json:"snow,omitempty"`
	} `json:"hourly"`
	Daily []struct {
		Dt        int64   `json:"dt"`
		Sunrise   int     `json:"sunrise"`
		Sunset    int     `json:"sunset"`
		Moonrise  int     `json:"moonrise"`
		Moonset   int     `json:"moonset"`
		MoonPhase float64 `json:"moon_phase"`
		Summary   string  `json:"summary"`
		Temp      struct {
			Day   float64 `json:"day"`
			Min   float64 `json:"min"`
			Max   float64 `json:"max"`
			Night float64 `json:"night"`
			Eve   float64 `json:"eve"`
			Morn  float64 `json:"morn"`
		} `json:"temp"`
		FeelsLike struct {
			Day   float64 `json:"day"`
			Night float64 `json:"night"`
			Eve   float64 `json:"eve"`
			Morn  float64 `json:"morn"`
		} `json:"feels_like"`
		Pressure  int     `json:"pressure"`
		Humidity  int     `json:"humidity"`
		DewPoint  float64 `json:"dew_point"`
		WindSpeed float64 `json:"wind_speed"`
		WindDeg   int     `json:"wind_deg"`
		WindGust  float64 `json:"wind_gust"`
		Weather   []struct {
			ID          int    `json:"id"`
			Main        string `json:"main"`
			Description string `json:"description"`
			Icon        string `json:"icon"`
		} `json:"weather"`
		Clouds int     `json:"clouds"`
		Pop    float64 `json:"pop"`
		Rain   float64 `json:"rain,omitempty"`
		Uvi    float64 `json:"uvi"`
	} `json:"daily"`
}

func GetWeather() (WeatherResponse, Coords) {
    	home, err := os.UserHomeDir()
    	if err != nil {
        	log.Fatalf("Failed to read homedir with %v", err)
    	}
	key := readFile(fmt.Sprint(home, "/.config/porch/key.txt"))
	var city string
	if len(os.Args) < 2 {
		city = readFile(fmt.Sprint(home, "/.config/porch/defaultCity.txt"))
	} else {
		var b strings.Builder
		b.WriteString(os.Args[1])
		if len(os.Args) > 2 {
			for _, v := range os.Args[2:] {
				b.WriteString(fmt.Sprintf(" %s", v))
			}
		}
		city = b.String()
	}

	cityMemo := fmt.Sprint(home, "/.config/porch/cities.csv")
	var coords Coords
	coords, found := memoRead(city, cityMemo)
	if !found {
		cityQuery := fmtCityQuery(strings.ReplaceAll(city, " ", "_"), key)
		resp := getUrlResponse(cityQuery)
		var coordsResp coordsResponse
		err := json.Unmarshal(resp, &coordsResp)
		if err != nil {
			panic(err)
		}
		if len(coordsResp) < 1 {
    			log.Fatalf("No results found for city \"%s\"\n", city)
		}
		coords = coordsResp[0]
		rec := coords.toStringRec()
		memoWrite(rec, cityMemo)
	}

	weatherQuery := fmtWeatherQuery(coords.Lat, coords.Lon, key)
	resp := getUrlResponse(weatherQuery)
	var weatherResp WeatherResponse
	err = json.Unmarshal(resp, &weatherResp)
	if err != nil {
		panic(err)
	}
	return weatherResp, coords
}

func readFile(keyfile string) string {
	k, err := os.ReadFile(keyfile)
	if err != nil {
		panic(err)
	}
	return strings.TrimSpace(string(k))
}

func fmtCityQuery(city string, key string) string {
	return fmt.Sprintf("https://api.openweathermap.org/geo/1.0/direct?q=%s&limit=1&appid=%s", city, key)
}

func fmtWeatherQuery(lat float64, lon float64, key string) string {
	return fmt.Sprintf("https://api.openweathermap.org/data/3.0/onecall?lat=%f&lon=%f&appid=%s&units=imperial", lat, lon, key)
}

func getUrlResponse(u string) []byte {
	resp, err := http.Get(u)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		panic(err)
	}
	return body
}

func (c Coords) toStringRec() []string {
	return []string{
		c.Name,
		strconv.FormatFloat(c.Lat, 'f', -1, 64),
		strconv.FormatFloat(c.Lon, 'f', -1, 64),
		c.Country,
		c.State,
	}
}
func coordsFromStringRec(rec []string) Coords {
	lat, err := strconv.ParseFloat(rec[1], 64)
	if err != nil {
		panic(err)
	}
	lon, err := strconv.ParseFloat(rec[2], 64)
	if err != nil {
		panic(err)
	}
	return Coords{
		rec[0],
		lat,
		lon,
		rec[3],
		rec[4],
	}
}

func memoRead(city string, memoP string) (Coords, bool) {
	f, err := os.OpenFile(memoP, os.O_RDONLY|os.O_CREATE, 0666)
	if err != nil {
		panic(err)
	}
	defer f.Close()

	reader := csv.NewReader(f)
	existing, err := reader.ReadAll()
	if err != nil {
		panic(err)
	}

	// Does this record already exist?
	for _, rec := range existing {
		if rec[0] == city {
			return coordsFromStringRec(rec), true
		}
	}
	return Coords{}, false
}

// Write a record. Does not check for duplication.
func memoWrite(r []string, memoP string) {
	f, err := os.OpenFile(memoP, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0666)
	if err != nil {
		panic(err)
	}
	defer f.Close()

	writer := csv.NewWriter(f)
	writer.Write(r)
	writer.Flush()
}