package gitlab

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"
)

func New(token string) *RestClient {
	return &RestClient{token: token, client: http.DefaultClient, baseUrl: "https://gitlab.com"}
}

type RestClient struct {
	client  *http.Client
	token   string
	baseUrl string
}

func (r *RestClient) UpdateCleanupPolicy(project string, versions []string) error {
	options := ProjectConfig{
		ContainerExpirationPolicyAttributes: ContainerExpirationPolicyAttributes{
			Cadence:       "1d",
			Enabled:       true,
			KeepN:         10,
			OlderThan:     "14d",
			NameRegex:     ".*",
			NameRegexKeep: fmt.Sprintf("(main|master|%s)", strings.Join(versions, "|")),
		},
	}
	buff := &bytes.Buffer{}
	encoder := json.NewEncoder(buff)
	err := encoder.Encode(&options)
	if err != nil {
		return err
	}
	return r.projectApiCall("PUT", project, "", io.NopCloser(buff), nil)
}

func (r *RestClient) GetTags(project string) ([]Tag, error) {
	var tags []Tag
	err := r.projectApiCall("GET", project, "/repository/tags", nil, &tags)
	return tags, err
}

func (r *RestClient) projectApiCall(method, project string, api string, body io.ReadCloser, response interface{}) error {
	encoded := url.QueryEscape(project)
	reqUrl, err := url.Parse(fmt.Sprintf("%s/api/v4/projects/%s%s", r.baseUrl, encoded, api))
	if err != nil {
		return err
	}
	header := http.Header{}
	header.Add("Content-Type", "application/json;charset=UTF-8")
	header.Add("PRIVATE-TOKEN", r.token)
	req := &http.Request{
		Method: method,
		URL:    reqUrl,
		Header: header,
		Body:   body,
	}
	resp, err := r.client.Do(req)
	if err != nil {
		return err
	}
	if resp.StatusCode == http.StatusOK && response != nil {
		decoder := json.NewDecoder(resp.Body)
		err = decoder.Decode(response)
	}
	return err
}

type ProjectConfig struct {
	ContainerExpirationPolicyAttributes ContainerExpirationPolicyAttributes `json:"container_expiration_policy_attributes"`
}

type ContainerExpirationPolicyAttributes struct {
	Cadence       string `json:"cadence"`
	Enabled       bool   `json:"enabled"`
	KeepN         int    `json:"keep_n"`
	OlderThan     string `json:"older_than"`
	NameRegex     string `json:"name_regex"`
	NameRegexKeep string `json:"name_regex_keep"`
}

type Tag struct {
	Commit    Commit      `json:"commit"`
	Release   Release     `json:"release"`
	Name      string      `json:"name"`
	Target    string      `json:"target"`
	Message   interface{} `json:"message"`
	Protected bool        `json:"protected"`
}

type Commit struct {
	ID             string    `json:"id"`
	ShortID        string    `json:"short_id"`
	Title          string    `json:"title"`
	CreatedAt      time.Time `json:"created_at"`
	ParentIds      []string  `json:"parent_ids"`
	Message        string    `json:"message"`
	AuthorName     string    `json:"author_name"`
	AuthorEmail    string    `json:"author_email"`
	AuthoredDate   string    `json:"authored_date"`
	CommitterName  string    `json:"committer_name"`
	CommitterEmail string    `json:"committer_email"`
	CommittedDate  string    `json:"committed_date"`
}

type Release struct {
	TagName     string `json:"tag_name"`
	Description string `json:"description"`
}