/*
 *	Scope - A simple and minimal metasearch engine
 *	Copyright (C) 2021 Arsen Musayelyan
 *
 *	This program is free software: you can redistribute it and/or modify
 *	it under the terms of the GNU Affero General Public License as published by
 *	the Free Software Foundation, either version 3 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU Affero General Public License for more details.
 *
 *	You should have received a copy of the GNU Affero General Public License
 *	along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package cards

import (
	"encoding/json"
	"fmt"
	"html/template"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"

	"github.com/bcicen/go-units"
	"github.com/spf13/viper"
)

func init() {
	Register("metaweather", 1, NewMetaweatherCard)
}

const metaweatherContent = `
<div class="columns">
	<div class="column">
		<span class="iconify" data-width="75" data-height="75" data-icon="%s"></span><p class="subtitle">%s</p>
	</div>
	<div class="column has-text-right">
		<p class="title has-text-weight-normal">%s</p>
	</div>
</div>
<div class="columns">
	<div class="column has-text-centered">
		<p><b>Min Temp:</b> %s</p>
		<p><b>Max Temp:</b> %s</p>
		<p><b>Wind Speed:</b> %s</p>
	</div>
	<div class="column has-text-centered">
		<p><b>Humidity:</b> %d%%</p>
		<p><b>Visibility:</b> %s</p>
		<p><b>Predictability:</b> %d%%</p>
	</div>
	<div class="column has-text-centered">
		<p><b>Wind Direction:</b> %s</p>
		<p><b>Location:</b> %s</p>
		<p><b>Timezone:</b> %s</p>
	</div>
</div>`

// weatherIconMap maps metaweather abbreviations
// to iconify icons
var weatherIconMap = map[string]string{
	"sn": "bi:cloud-snow",
	"sl": "bi:cloud-sleet",
	"h":  "bi:cloud-hail",
	"t":  "bi:cloud-lightning-rain",
	"hr": "bi:cloud-rain-heavy",
	"lr": "bi:cloud-drizzle",
	"s":  "wi:day-rain",
	"hc": "bi:cloud-fill",
	"lc": "bi:cloud",
	"c":  "akar-icons:sun",
}

// MetaweatherCard represents a metaweather card
type MetaweatherCard struct {
	query     string
	userAgent string
	location  []MetaweatherLocation
	resp      MetaweatherResponse
}

// NewMetaweatherCard is a NewCardFunc that creates a new MetaweatherCard
func NewMetaweatherCard(query, userAgent string) Card {
	return &MetaweatherCard{
		query:     query,
		userAgent: userAgent,
	}
}

// MetaweatherLocation represents a location
type MetaweatherLocation struct {
	Title string `json:"title"`
	WOEID int    `json:"woeid"`
}

// MetaweatherResponse represents a response from
// the metaweather API
type MetaweatherResponse struct {
	Detail       string `json:"detail"`
	Title        string `json:"title"`
	Timezone     string `json:"timezone"`
	Consolidated []struct {
		ID             int     `json:"id"`
		State          string  `json:"weather_state_name"`
		StateAbbr      string  `json:"weather_state_abbr"`
		WindCompass    string  `json:"wind_direction_compass"`
		MinTemp        float64 `json:"min_temp"`
		MaxTemp        float64 `json:"max_temp"`
		CurrentTemp    float64 `json:"the_temp"`
		WindSpeed      float64 `json:"wind_speed"`
		WindDirection  float64 `json:"wind_direction"`
		AirPressure    float64 `json:"air_pressure"`
		Visibility     float64 `json:"visibility"`
		Humidity       int     `json:"humidity"`
		Predictability int     `json:"predictability"`
	} `json:"consolidated_weather"`
}

// RunQuery searches for the location and then runs an API query
// using the returned WOEID
func (mc *MetaweatherCard) RunQuery() error {
	http.DefaultClient.Timeout = 5 * time.Second

	// Create location search request
	req, err := http.NewRequest(
		http.MethodGet,
		"https://www.metaweather.com/api/location/search/?query="+url.QueryEscape(mc.StripKey()),
		nil,
	)
	if err != nil {
		return err
	}
	req.Header.Set("User-Agent", mc.userAgent)

	// Perform request
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}

	// Decode response into location
	err = json.NewDecoder(res.Body).Decode(&mc.location)
	if err != nil {
		return err
	}

	res.Body.Close()

	// If no locations, search returned no results
	if len(mc.location) == 0 {
		return nil
	}

	// Create request for weather data
	req, err = http.NewRequest(
		http.MethodGet,
		"https://www.metaweather.com/api/location/"+strconv.Itoa(mc.location[0].WOEID),
		nil,
	)
	if err != nil {
		return err
	}
	req.Header.Set("User-Agent", mc.userAgent)

	// Perform request
	res, err = http.DefaultClient.Do(req)
	if err != nil {
		return err
	}

	// Decode response into response struct
	err = json.NewDecoder(res.Body).Decode(&mc.resp)
	if err != nil {
		return err
	}

	return nil
}

// Returned checks whether no location was found or response
// said not found.
func (mc *MetaweatherCard) Returned() bool {
	return len(mc.location) > 0 && mc.resp.Detail != "Not found."
}

// Matches determines whether the query matches the keys for
// MetaweatherCard
func (mc *MetaweatherCard) Matches() bool {
	return strings.HasPrefix(mc.query, "weather in") ||
		strings.HasPrefix(mc.query, "weather") ||
		strings.HasSuffix(mc.query, "weather")
}

// StripKey removes keys related to MetaweatherCard
func (mc *MetaweatherCard) StripKey() string {
	query := strings.TrimPrefix(mc.query, "weather in")
	query = strings.TrimPrefix(query, "weather")
	query = strings.TrimSuffix(query, "weather")
	return strings.TrimSpace(query)
}

// Content returns metaweatherContent with all information added
func (mc *MetaweatherCard) Content() template.HTML {
	return template.HTML(fmt.Sprintf(
		metaweatherContent,
		// Write iconift icon for weather state
		weatherIconMap[mc.resp.Consolidated[0].StateAbbr],
		// Write weather state
		mc.resp.Consolidated[0].State,
		// Convert and write current temperature
		convert(mc.resp.Consolidated[0].CurrentTemp, "temperature", units.Celsius),
		// Convert and write minimum temperature
		convert(mc.resp.Consolidated[0].MinTemp, "temperature", units.Celsius),
		// Convert and write maximum temperature
		convert(mc.resp.Consolidated[0].MaxTemp, "temperature", units.Celsius),
		// Write wind speed
		fmt.Sprintf("%.2f mph", mc.resp.Consolidated[0].WindSpeed),
		// Write humidity percentafe
		mc.resp.Consolidated[0].Humidity,
		// Convert and write visibility
		convert(mc.resp.Consolidated[0].Visibility, "visibility", units.Mile),
		// Write predictability percentage
		mc.resp.Consolidated[0].Predictability,
		// Write compass wind direction
		mc.resp.Consolidated[0].WindCompass,
		// Write title
		mc.resp.Title,
		// Write timezone
		mc.resp.Timezone,
	))
}

// Title of MetaweatherCard is "Weather"
func (mc *MetaweatherCard) Title() string {
	return "Weather"
}

// Footer returns a footer with a link to metaweather
func (mc *MetaweatherCard) Footer() template.HTML {
	return `<div class="card-footer"><a class="card-footer-item" href="https://www.metaweather.com/">Metaweather</a></div>`
}

// Head returns an empty string as no extra head tags
// are required for MetaweatherCard
func (mc *MetaweatherCard) Head() template.HTML {
	return ""
}

// convert converts a value to a unit specified in the config, and then formats it
func convert(val float64, suffix string, defaultUnit units.Unit) string {
	// Find unit in config
	unit, err := units.Find(viper.GetString("search.cards.weather.units." + suffix))
	if err != nil {
		unit = defaultUnit
	}
	// Convert value to specified unit
	newVal, err := units.ConvertFloat(val, defaultUnit, unit)
	opts := units.FmtOptions{
		Label:     true,
		Short:     true,
		Precision: 2,
	}
	if err != nil {
		return units.NewValue(val, defaultUnit).Fmt(opts)
	}
	return newVal.Fmt(opts)
}