package fitbit

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"golang.org/x/oauth2"
	oauth2fitbit "golang.org/x/oauth2/fitbit"
)

var oauth2Config = &oauth2.Config{
	ClientID:     "@FITBIT_CLIENT_ID@",
	ClientSecret: "@FITBIT_CLIENT_SECRET@",
	Endpoint:     oauth2fitbit.Endpoint,
	RedirectURL:  "https://fitbit-gfit-sync.appspot.com/fitbit/grant",
	Scopes:       []string{"activity"},
}

type Activity struct {
	ActivityID       int     `json:"activityId"`
	ActivityParentID int     `json:"activityParentId"`
	Calories         int     `json:"calories"`
	Description      string  `json:"description"`
	Distance         float64 `json:"distance"`
	Duration         int     `json:"duration"`
	HasStartTime     bool    `json:"hasStartTime"`
	IsFavorite       bool    `json:"isFavorite"`
	LogID            int     `json:"logId"`
	Name             string  `json:"name"`
	StartTime        string  `json:"startTime"`
	Steps            int     `json:"steps"`
}

type Distance struct {
	Activity string  `json:"activity"`
	Distance float64 `json:"distance"`
}

type ActivitySummary struct {
	Activities []Activity `json:"activities"`
	Goals      struct {
		CaloriesOut int     `json:"caloriesOut"`
		Distance    float64 `json:"distance"`
		Floors      int     `json:"floors"`
		Steps       int     `json:"steps"`
	} `json:"goals"`
	Summary struct {
		ActivityCalories     int        `json:"activityCalories"`
		CaloriesBMR          int        `json:"caloriesBMR"`
		CaloriesOut          int        `json:"caloriesOut"`
		MarginalCalories     int        `json:"marginalCalories"`
		Distances            []Distance `json:"distances"`
		Elevation            float64    `json:"elevation"`
		Floors               int        `json:"floors"`
		Steps                int        `json:"steps"`
		SedentaryMinutes     int        `json:"sedentaryMinutes"`
		LightlyActiveMinutes int        `json:"lightlyActiveMinutes"`
		FairlyActiveMinutes  int        `json:"fairlyActiveMinutes"`
		VeryActiveMinutes    int        `json:"veryActiveMinutes"`
	} `json:"summary"`
}

type Client struct {
	userID string
	client *http.Client
}

func NewClient(ctx context.Context, userID string, tok *oauth2.Token) *Client {
	return &Client{
		userID: userID,
		client: oauth2Config.Client(ctx, tok),
	}
}

func (c *Client) ActivitySummary(t time.Time) (*ActivitySummary, error) {
	url := fmt.Sprintf("https://api.fitbit.com/1/user/%s/activity/date/%s.json",
		c.userID, t.Format("2006-01-02"))

	res, err := c.client.Get(url)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	var summary ActivitySummary
	if err := json.NewDecoder(res.Body).Decode(&summary); err != nil {
		return nil, err
	}

	return &summary, nil
}