monorail/monorail.go

// Copyright 2021 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package monorail

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"time"

	"github.com/pkg/errors"
	"go.skia.org/infra/go/auth"
	"go.skia.org/infra/go/httputils"
	"go.skia.org/infra/go/util"
	compute "google.golang.org/api/compute/v1"
)

const (
	// monorailBaseURLTemplate is the template for building the Monorail url.
	monorailBaseURLTemplate = "https://monorail-prod.appspot.com/_ah/api/monorail/v1/projects/%s/issues"
	// monorailIssueReferenceTemplate is the template for the user-facing Monorail instance url.
	// For testing, use the staging server at https://bugs-staging.fuchsia.dev.
	monorailIssueReferenceTemplate = "https://bugs.fuchsia.dev/p/fuchsia/issues/detail?id=%v"
)

type IssueTracker struct {
	client  *http.Client
	project string
	url     string
}

// IssueRef is a link from a Monorail issue to another Monorail issue, possibly in a different
// project.
type IssueRef struct {
	IssueID   int64  `json:"issueId"`
	ProjectID string `json:"projectId"`
}

// IssuePerson is an entity representing a person in Monorail. It is used to describe reporters of
// issues, authors of comments, etc.
type IssuePerson struct {
	EMailBouncing bool   `json:"email_bouncing"`
	HTMLLink      string `json:"htmlLink"`
	Name          string `json:"name"`
}

type Status string

type IssueRequest struct {
	CC          []IssuePerson `json:"cc"`
	Components  []string      `json:"components,omitempty"`
	Description string        `json:"description"`
	Labels      []string      `json:"labels"`
	Owner       IssuePerson   `json:"owner"`
	Status      string        `json:"status"`
	Summary     string        `json:"summary"`
}

type NewIssueResponse struct {
	Author     IssuePerson `json:"author"`
	Components []string    `json:"components"`
	ID         int64       `json:"id"`
	Labels     []string    `json:"labels"`
	Published  string      `json:"published"`
	Status     string      `json:"status"`
	Summary    string      `json:"summary"`
	Title      string      `json:"title"`
}

// Available "can" values in the Monorail api. Reference:
// https://chromium.googlesource.com/infra/infra/+/master/appengine/monorail/doc/api.md
type CannedQuery int

const (
	All CannedQuery = iota
	New
	Open
	Owned
	Starred
	ToVerify
)

func (s CannedQuery) String() string {
	return [...]string{"all", "new", "open", "owned", "starred", "to_verify"}[s]
}

type IssueQuery struct {
	Can          CannedQuery
	Labels       []string
	SearchString string
}

type NewCommentResponse struct {
	Content string `json:"content"`
	ID      int64  `json:"id"`
}

type UTCTime time.Time

// UnmarshalJSON parses time in the format used by Monorail JSON API.
func (t *UTCTime) UnmarshalJSON(data []byte) error {
	var s string
	if err := json.Unmarshal(data, &s); err != nil {
		return err
	}
	p, err := time.Parse("2006-01-02T15:04:05", s)
	if err != nil {
		return err
	}
	*t = UTCTime(p)
	return nil
}

func (t UTCTime) After(u UTCTime) bool {
	v := time.Time(t)
	w := time.Time(u)
	return v.After(w)
}

// Issue is a Monorail entity representing an issue / bug.
type Issue struct {
	Author            *IssuePerson   `json:"author"`
	BlockedOn         []*IssueRef    `json:"blockedOn"`
	Blocking          []*IssueRef    `json:"blocking"`
	CC                []*IssuePerson `json:"cc"`
	CanComment        bool           `json:"canComment"`
	CanEdit           bool           `json:"canEdit"`
	Closed            UTCTime        `json:"closed"`
	ComponentModified UTCTime        `json:"component_modified"`
	Components        []string       `json:"components"`
	ID                int64          `json:"id"`
	Labels            []string       `json:"labels"`
	Owner             *IssuePerson   `json:"owner"`
	OwnerModified     UTCTime        `json:"owner_modified"`
	ProjectID         string         `json:"projectId"`
	Published         UTCTime        `json:"published"`
	Starred           bool           `json:"starred"`
	Stars             int64          `json:"stars"`
	State             string         `json:"state"`
	Status            Status         `json:"status"`
	StatusModified    UTCTime        `json:"status_modified"`
	Summary           string         `json:"summary"`
	Updated           UTCTime        `json:"updated"`
}

type IssueResponse struct {
	Items        []Issue `json:"items"`
	TotalResults int64   `json:"totalResults"`
}

// IssueComment is an entity representing a comment in Monorail.
type IssueComment struct {
	Author    *IssuePerson `json:"author"`
	CanDelete bool         `json:"canDelete"`
	Content   string       `json:"content"`
	DeletedBy *IssuePerson `json:"deletedBy"`
	ID        int64        `json:"id"`
	Published UTCTime      `json:"published"`
}

type CommentUpdates struct {
	Cc         []string `json:"cc,omitempty"`
	Components []string `json:"components,omitempty"`
	Labels     []string `json:"labels,omitempty"`
	Owner      string   `json:"owner,omitempty"`
	Status     string   `json:"status,omitempty"`
}

type CommentRequest struct {
	Content string         `json:"content"`
	Updates CommentUpdates `json:"updates,omitempty"`
}

type CommentResponse struct {
	Items []IssueComment `json:"items"`
}

type OptionalQueryParams map[string]string

// NewIssueTracker creates and returns an IssueTracker instance.
func NewIssueTracker(client *http.Client, project string) *IssueTracker {
	return &IssueTracker{
		client:  client,
		project: project,
		url:     fmt.Sprintf(monorailBaseURLTemplate, project),
	}
}

func NewIssueTrackerFromLUCIContext(project string) (*IssueTracker, error) {
	ts, err := auth.NewLUCIContextTokenSource(compute.CloudPlatformScope)
	if err != nil {
		return nil, err
	}
	mrClient := httputils.DefaultClientConfig().WithTokenSource(ts).With2xxOnly().Client()
	return NewIssueTracker(mrClient, project), nil
}

// FromQuery returns Monorail issues matching a given search string.
func (m *IssueTracker) FromQuery(issueQuery IssueQuery, optionalQueryParams OptionalQueryParams) ([]Issue, error) {
	queryLink := buildQueryLink(m.url, issueQuery, optionalQueryParams)
	return getIssues(m.client, queryLink)
}

// IssueComments returns comments on a Monorail issue.
func (m *IssueTracker) IssueComments(id int64) ([]IssueComment, error) {
	u := fmt.Sprintf("%s/%d/comments?maxResults=10000", m.url, id)
	return getComments(m.client, u)
}

// AddComment adds a comment to the issue with the given id.
func (m *IssueTracker) AddComment(id int64, comment CommentRequest) error {
	u := fmt.Sprintf("%s/%d/comments?sendEmail=true", m.url, id)
	if err := post(m.client, u, comment, logSuccessfulCommentPost); err != nil {
		return errors.Wrap(err, "failed to add comment to Monorail issue")
	}
	return nil
}

// buildQueryLink combines default and optional query parameters into a usable url
// for Monorail's RESTful API.
func buildQueryLink(baseURL string, issueQuery IssueQuery, optionalQueryParams OptionalQueryParams) string {
	query := url.Values{}

	// add required params
	query.Add("can", fmt.Sprint(issueQuery.Can))
	for _, label := range issueQuery.Labels {
		query.Add("label", label)
	}
	// Monorail defaults to only returning the last 100 issues, but allows up to 1000 issues in a single request.
	query.Add("maxResults", "1000")
	query.Add("q", issueQuery.SearchString)
	query.Add("fields", "items/id,items/summary,items/stars,items/starred,items/status,items/state,items/labels,items/author,items/owner,items/cc,items/updated,items/published,items/closed,items/blockedOn,items/blocking,items/projectId,items/canComment,items/canEdit,items/components,items/component_modified,items/owner_modified,items/status_modified")

	// add optional params
	for k, v := range optionalQueryParams {
		query.Add(k, v)
	}

	return fmt.Sprintf("%s?%s", baseURL, query.Encode())
}

func getComments(client *http.Client, u string) ([]IssueComment, error) {
	resp, err := client.Get(u)
	if err != nil || resp == nil {
		return nil, fmt.Errorf("Failed to retrieve Monorail response: %s", err)
	}
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("Unexpected Monorail response. Expected %d, received %d", http.StatusOK, resp.StatusCode)
	}
	defer util.Close(resp.Body)

	commentResponse := &CommentResponse{
		Items: []IssueComment{},
	}

	if err := json.NewDecoder(resp.Body).Decode(&commentResponse); err != nil {
		return nil, err
	}

	return commentResponse.Items, nil
}

// AddIssue creates an issue with the passed in params.
func (m *IssueTracker) AddIssue(issue IssueRequest) (NewIssueResponse, error) {
	req := struct {
		IssueRequest
		Project string `json:"projectId"`
	}{
		IssueRequest: issue,
		Project:      m.project,
	}

	newIssueResponse := NewIssueResponse{}

	callback := func(resp []byte) error {
		if err := json.Unmarshal(resp, &newIssueResponse); err != nil {
			return errors.Wrap(err, "unable to unmarshal new Monorail issue response")
		}
		issueURL := fmt.Sprintf(monorailIssueReferenceTemplate, newIssueResponse.ID)
		log.Printf("Issue filed!\nSummary:\n%s\nReference: %s\n", newIssueResponse.Summary, issueURL)
		return nil
	}
	// since this request modifies a resource, send an email.
	err := post(m.client, m.url+"?sendEmail=true", req, callback)
	return newIssueResponse, err
}

func getIssues(client *http.Client, u string) ([]Issue, error) {
	resp, err := client.Get(u)
	if err != nil || resp == nil {
		return nil, fmt.Errorf("Failed to retrieve Monorail response: %s", err)
	}
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("Unexpected Monorail response. Expected %d, received %d", http.StatusOK, resp.StatusCode)
	}
	defer util.Close(resp.Body)

	issueResponse := &IssueResponse{}

	if err := json.NewDecoder(resp.Body).Decode(&issueResponse); err != nil {
		return nil, err
	}

	return issueResponse.Items, nil
}

func logSuccessfulCommentPost(resp []byte) error {
	newCommentResponse := NewCommentResponse{}
	if err := json.Unmarshal(resp, &newCommentResponse); err != nil {
		return errors.Wrap(err, "unable to unmarshal new Monorail comment response")
	}
	log.Printf("Comment added! \nSummary: \n%s\n", newCommentResponse.Content)
	return nil
}

func post(client *http.Client, dst string, request interface{}, callback func(r []byte) error) error {
	b := &bytes.Buffer{}
	e := json.NewEncoder(b)
	if err := e.Encode(request); err != nil {
		return errors.Wrap(err, "failed to encode json for request")
	}

	resp, err := client.Post(dst, "application/json", b)
	if err != nil || resp == nil {
		return errors.Wrap(err, "failed to retrieve Monorail response")
	}
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("Unexpected Monorail response. Expected %d, received %d", http.StatusOK, resp.StatusCode)
	}

	defer util.Close(resp.Body)
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return errors.Wrap(err, "failed to read response body")
	}

	if err := callback(body); err != nil {
		return errors.Wrap(err, "failed to log Monorail post request")
	}

	return nil
}