package threadsapi

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

type MediaStats struct {
	LikeCount   int `json:"like_count"`
	ReplyCount  int `json:"reply_count"`
	RepostCount int `json:"repost_count"`
	QuoteCount  int `json:"quote_count"`
}

func GetMediaStats(ctx context.Context, accessToken, mediaID string) (*MediaStats, error) {
	u := fmt.Sprintf("%s/%s", graphBaseURL, mediaID)
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
	if err != nil {
		return nil, err
	}
	q := url.Values{}
	q.Set("fields", "like_count,reply_count,repost_count,quote_count")
	q.Set("access_token", accessToken)
	req.URL.RawQuery = q.Encode()

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("threads api media stats error: %s", resp.Status)
	}

	var raw struct {
		ID          string `json:"id"`
		LikeCount   int    `json:"like_count"`
		ReplyCount  int    `json:"reply_count"`
		RepostCount int    `json:"repost_count"`
		QuoteCount  int    `json:"quote_count"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&raw); err != nil {
		return nil, err
	}
	return &MediaStats{
		LikeCount:   raw.LikeCount,
		ReplyCount:  raw.ReplyCount,
		RepostCount: raw.RepostCount,
		QuoteCount:  raw.QuoteCount,
	}, nil
}

type TokenRefreshResult struct {
	AccessToken string `json:"access_token"`
	TokenType   string `json:"token_type"`
	ExpiresIn   int    `json:"expires_in"`
}

func RefreshAccessToken(ctx context.Context, currentToken string) (*TokenRefreshResult, error) {
	u := fmt.Sprintf("%s/refresh_access_token", graphBaseURL)
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
	if err != nil {
		return nil, err
	}
	q := url.Values{}
	q.Set("grant_type", "th_refresh_token")
	q.Set("access_token", currentToken)
	req.URL.RawQuery = q.Encode()

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("threads api token refresh error: %s", resp.Status)
	}

	var result TokenRefreshResult
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return nil, err
	}
	if result.AccessToken == "" {
		return nil, fmt.Errorf("threads api token refresh returned empty token")
	}
	return &result, nil
}

func NsFromNow(seconds int) int64 {
	return time.Now().UnixNano() + int64(seconds)*1e9
}