package mailchimp

import (
	"crypto/md5"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"net/http"
	"strings"

	"github.com/sirupsen/logrus"
	"github.com/spf13/viper"
)

type MailchimpAPI struct {
	APIKey     string
	Server     string
	AudienceID string
}

type Member struct {
	EmailAddress string `json:"email_address"`
	Status       string `json:"status_if_new,omitempty"`
}

func NewMailchimpAPI() *MailchimpAPI {
	return &MailchimpAPI{
		APIKey:     viper.GetString("mailchimp.api_key"),
		Server:     viper.GetString("mailchimp.server"),
		AudienceID: viper.GetString("mailchimp.audience_id"),
	}
}

func (api *MailchimpAPI) emailHash(email string) string {
	hash := md5.Sum([]byte(strings.ToLower(email)))
	return hex.EncodeToString(hash[:])
}

func (api *MailchimpAPI) EmailExists(email string) (bool, error) {
	hash := api.emailHash(email)
	url := fmt.Sprintf("https://%s.api.mailchimp.com/3.0/lists/%s/members/%s",
		api.Server,
		api.AudienceID,
		hash)

	req, _ := http.NewRequest("GET", url, nil)
	req.SetBasicAuth("anystring", api.APIKey)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return false, err
	}
	defer resp.Body.Close()

	return resp.StatusCode == http.StatusOK, nil
}

func (api *MailchimpAPI) AddEmail(email string) error {
	url := fmt.Sprintf("https://%s.api.mailchimp.com/3.0/lists/%s/members",
		api.Server,
		api.AudienceID)

	member := Member{
		EmailAddress: email,
		Status:       "subscribed",
	}
	body, _ := json.Marshal(member)

	req, _ := http.NewRequest("POST", url, strings.NewReader(string(body)))
	req.SetBasicAuth("anystring", api.APIKey)
	req.Header.Add("Content-Type", "application/json")

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

	if resp.StatusCode >= 400 {
		return fmt.Errorf("failed to add email: %s", email)
	}
	return nil
}

func (api *MailchimpAPI) TagEmail(email, tag string) error {
	hash := api.emailHash(email)
	url := fmt.Sprintf("https://%s.api.mailchimp.com/3.0/lists/%s/members/%s/tags",
		api.Server,
		api.AudienceID,
		hash)

	body := map[string]interface{}{
		"tags": []map[string]string{
			{"name": tag, "status": "active"},
		},
	}
	jsonBody, _ := json.Marshal(body)

	req, _ := http.NewRequest("POST", url, strings.NewReader(string(jsonBody)))
	req.SetBasicAuth("anystring", api.APIKey)
	req.Header.Add("Content-Type", "application/json")

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

	if resp.StatusCode >= 400 {
		logrus.Errorf("Tagging failed: status %d", resp.StatusCode)
		return fmt.Errorf("failed to tag email: %s", email)
	}
	return nil
}