glance/internal/glance/widget-custom-api.go

594 lines
14 KiB
Go

package glance
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"html/template"
"io"
"log/slog"
"math"
"net/http"
"regexp"
"sort"
"strconv"
"strings"
"sync"
"time"
"github.com/tidwall/gjson"
)
var customAPIWidgetTemplate = mustParseTemplate("custom-api.html", "widget-base.html")
// Needs to be exported for the YAML unmarshaler to work
type CustomAPIRequest struct {
URL string `yaml:"url"`
AllowInsecure bool `yaml:"allow-insecure"`
Headers map[string]string `yaml:"headers"`
Parameters queryParametersField `yaml:"parameters"`
Method string `yaml:"method"`
BodyType string `yaml:"body-type"`
Body any `yaml:"body"`
SkipJSONValidation bool `yaml:"skip-json-validation"`
bodyReader io.ReadSeeker `yaml:"-"`
httpRequest *http.Request `yaml:"-"`
}
type customAPIWidget struct {
widgetBase `yaml:",inline"`
*CustomAPIRequest `yaml:",inline"` // the primary request
Subrequests map[string]*CustomAPIRequest `yaml:"subrequests"`
Template string `yaml:"template"`
Frameless bool `yaml:"frameless"`
compiledTemplate *template.Template `yaml:"-"`
CompiledHTML template.HTML `yaml:"-"`
}
func (widget *customAPIWidget) initialize() error {
widget.withTitle("Custom API").withCacheDuration(1 * time.Hour)
if err := widget.CustomAPIRequest.initialize(); err != nil {
return fmt.Errorf("initializing primary request: %v", err)
}
for key := range widget.Subrequests {
if err := widget.Subrequests[key].initialize(); err != nil {
return fmt.Errorf("initializing subrequest %q: %v", key, err)
}
}
if widget.Template == "" {
return errors.New("template is required")
}
compiledTemplate, err := template.New("").Funcs(customAPITemplateFuncs).Parse(widget.Template)
if err != nil {
return fmt.Errorf("parsing template: %w", err)
}
widget.compiledTemplate = compiledTemplate
return nil
}
func (widget *customAPIWidget) update(ctx context.Context) {
compiledHTML, err := fetchAndParseCustomAPI(widget.CustomAPIRequest, widget.Subrequests, widget.compiledTemplate)
if !widget.canContinueUpdateAfterHandlingErr(err) {
return
}
widget.CompiledHTML = compiledHTML
}
func (widget *customAPIWidget) Render() template.HTML {
return widget.renderTemplate(widget, customAPIWidgetTemplate)
}
func (req *CustomAPIRequest) initialize() error {
if req.URL == "" {
return errors.New("URL is required")
}
if req.Body != nil {
if req.Method == "" {
req.Method = http.MethodPost
}
if req.BodyType == "" {
req.BodyType = "json"
}
if req.BodyType != "json" && req.BodyType != "string" {
return errors.New("invalid body type, must be either 'json' or 'string'")
}
switch req.BodyType {
case "json":
encoded, err := json.Marshal(req.Body)
if err != nil {
return fmt.Errorf("marshaling body: %v", err)
}
req.bodyReader = bytes.NewReader(encoded)
case "string":
bodyAsString, ok := req.Body.(string)
if !ok {
return errors.New("body must be a string when body-type is 'string'")
}
req.bodyReader = strings.NewReader(bodyAsString)
}
} else if req.Method == "" {
req.Method = http.MethodGet
}
httpReq, err := http.NewRequest(strings.ToUpper(req.Method), req.URL, req.bodyReader)
if err != nil {
return err
}
if len(req.Parameters) > 0 {
httpReq.URL.RawQuery = req.Parameters.toQueryString()
}
if req.BodyType == "json" {
httpReq.Header.Set("Content-Type", "application/json")
}
for key, value := range req.Headers {
httpReq.Header.Add(key, value)
}
req.httpRequest = httpReq
return nil
}
type customAPIResponseData struct {
JSON decoratedGJSONResult
Response *http.Response
}
type customAPITemplateData struct {
*customAPIResponseData
subrequests map[string]*customAPIResponseData
}
func (data *customAPITemplateData) JSONLines() []decoratedGJSONResult {
result := make([]decoratedGJSONResult, 0, 5)
gjson.ForEachLine(data.JSON.Raw, func(line gjson.Result) bool {
result = append(result, decoratedGJSONResult{line})
return true
})
return result
}
func (data *customAPITemplateData) Subrequest(key string) *customAPIResponseData {
req, exists := data.subrequests[key]
if !exists {
// We have to panic here since there's nothing sensible we can return and the
// lack of an error would cause requested data to return zero values which
// would be confusing from the user's perspective. Go's template module
// handles recovering from panics and will return the panic message as an
// error during template execution.
panic(fmt.Sprintf("subrequest with key %q has not been defined", key))
}
return req
}
func fetchCustomAPIRequest(ctx context.Context, req *CustomAPIRequest) (*customAPIResponseData, error) {
if req.bodyReader != nil {
req.bodyReader.Seek(0, io.SeekStart)
}
client := ternary(req.AllowInsecure, defaultInsecureHTTPClient, defaultHTTPClient)
resp, err := client.Do(req.httpRequest.WithContext(ctx))
if err != nil {
return nil, err
}
defer resp.Body.Close()
bodyBytes, err := io.ReadAll(resp.Body)
if err != nil {
return nil, err
}
body := strings.TrimSpace(string(bodyBytes))
if !req.SkipJSONValidation && body != "" && !gjson.Valid(body) {
truncatedBody, isTruncated := limitStringLength(body, 100)
if isTruncated {
truncatedBody += "... <truncated>"
}
slog.Error("Invalid response JSON in custom API widget", "url", req.httpRequest.URL.String(), "body", truncatedBody)
return nil, errors.New("invalid response JSON")
}
data := &customAPIResponseData{
JSON: decoratedGJSONResult{gjson.Parse(body)},
Response: resp,
}
return data, nil
}
func fetchAndParseCustomAPI(
primaryReq *CustomAPIRequest,
subReqs map[string]*CustomAPIRequest,
tmpl *template.Template,
) (template.HTML, error) {
var primaryData *customAPIResponseData
subData := make(map[string]*customAPIResponseData, len(subReqs))
var err error
if len(subReqs) == 0 {
// If there are no subrequests, we can fetch the primary request in a much simpler way
primaryData, err = fetchCustomAPIRequest(context.Background(), primaryReq)
} else {
// If there are subrequests, we need to fetch them concurrently
// and cancel all requests if any of them fail. There's probably
// a more elegant way to do this, but this works for now.
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
var wg sync.WaitGroup
var mu sync.Mutex // protects subData and err
wg.Add(1)
go func() {
defer wg.Done()
var localErr error
primaryData, localErr = fetchCustomAPIRequest(ctx, primaryReq)
mu.Lock()
if localErr != nil && err == nil {
err = localErr
cancel()
}
mu.Unlock()
}()
for key, req := range subReqs {
wg.Add(1)
go func() {
defer wg.Done()
var localErr error
var data *customAPIResponseData
data, localErr = fetchCustomAPIRequest(ctx, req)
mu.Lock()
if localErr == nil {
subData[key] = data
} else if err == nil {
err = localErr
cancel()
}
mu.Unlock()
}()
}
wg.Wait()
}
emptyBody := template.HTML("")
if err != nil {
return emptyBody, err
}
data := customAPITemplateData{
customAPIResponseData: primaryData,
subrequests: subData,
}
var templateBuffer bytes.Buffer
err = tmpl.Execute(&templateBuffer, &data)
if err != nil {
return emptyBody, err
}
return template.HTML(templateBuffer.String()), nil
}
type decoratedGJSONResult struct {
gjson.Result
}
func gJsonResultArrayToDecoratedResultArray(results []gjson.Result) []decoratedGJSONResult {
decoratedResults := make([]decoratedGJSONResult, len(results))
for i, result := range results {
decoratedResults[i] = decoratedGJSONResult{result}
}
return decoratedResults
}
func (r *decoratedGJSONResult) Exists(key string) bool {
return r.Get(key).Exists()
}
func (r *decoratedGJSONResult) Array(key string) []decoratedGJSONResult {
if key == "" {
return gJsonResultArrayToDecoratedResultArray(r.Result.Array())
}
return gJsonResultArrayToDecoratedResultArray(r.Get(key).Array())
}
func (r *decoratedGJSONResult) String(key string) string {
if key == "" {
return r.Result.String()
}
return r.Get(key).String()
}
func (r *decoratedGJSONResult) Int(key string) int {
if key == "" {
return int(r.Result.Int())
}
return int(r.Get(key).Int())
}
func (r *decoratedGJSONResult) Float(key string) float64 {
if key == "" {
return r.Result.Float()
}
return r.Get(key).Float()
}
func (r *decoratedGJSONResult) Bool(key string) bool {
if key == "" {
return r.Result.Bool()
}
return r.Get(key).Bool()
}
func customAPIDoMathOp[T int | float64](a, b T, op string) T {
switch op {
case "add":
return a + b
case "sub":
return a - b
case "mul":
return a * b
case "div":
if b == 0 {
return 0
}
return a / b
}
return 0
}
var customAPITemplateFuncs = func() template.FuncMap {
var regexpCacheMu sync.Mutex
var regexpCache = make(map[string]*regexp.Regexp)
getCachedRegexp := func(pattern string) *regexp.Regexp {
regexpCacheMu.Lock()
defer regexpCacheMu.Unlock()
regex, exists := regexpCache[pattern]
if !exists {
regex = regexp.MustCompile(pattern)
regexpCache[pattern] = regex
}
return regex
}
doMathOpWithAny := func(a, b any, op string) any {
switch at := a.(type) {
case int:
switch bt := b.(type) {
case int:
return customAPIDoMathOp(at, bt, op)
case float64:
return customAPIDoMathOp(float64(at), bt, op)
default:
return math.NaN()
}
case float64:
switch bt := b.(type) {
case int:
return customAPIDoMathOp(at, float64(bt), op)
case float64:
return customAPIDoMathOp(at, bt, op)
default:
return math.NaN()
}
default:
return math.NaN()
}
}
funcs := template.FuncMap{
"toFloat": func(a int) float64 {
return float64(a)
},
"toInt": func(a float64) int {
return int(a)
},
"add": func(a, b any) any {
return doMathOpWithAny(a, b, "add")
},
"sub": func(a, b any) any {
return doMathOpWithAny(a, b, "sub")
},
"mul": func(a, b any) any {
return doMathOpWithAny(a, b, "mul")
},
"div": func(a, b any) any {
return doMathOpWithAny(a, b, "div")
},
"now": func() time.Time {
return time.Now()
},
"offsetNow": func(offset string) time.Time {
d, err := time.ParseDuration(offset)
if err != nil {
return time.Now()
}
return time.Now().Add(d)
},
"duration": func(str string) time.Duration {
d, err := time.ParseDuration(str)
if err != nil {
return 0
}
return d
},
"parseTime": customAPIFuncParseTime,
"toRelativeTime": dynamicRelativeTimeAttrs,
"parseRelativeTime": func(layout, value string) template.HTMLAttr {
// Shorthand to do both of the above with a single function call
return dynamicRelativeTimeAttrs(customAPIFuncParseTime(layout, value))
},
// The reason we flip the parameter order is so that you can chain multiple calls together like this:
// {{ .JSON.String "foo" | trimPrefix "bar" | doSomethingElse }}
// instead of doing this:
// {{ trimPrefix (.JSON.String "foo") "bar" | doSomethingElse }}
// since the piped value gets passed as the last argument to the function.
"trimPrefix": func(prefix, s string) string {
return strings.TrimPrefix(s, prefix)
},
"trimSuffix": func(suffix, s string) string {
return strings.TrimSuffix(s, suffix)
},
"trimSpace": strings.TrimSpace,
"replaceAll": func(old, new, s string) string {
return strings.ReplaceAll(s, old, new)
},
"replaceMatches": func(pattern, replacement, s string) string {
if s == "" {
return ""
}
return getCachedRegexp(pattern).ReplaceAllString(s, replacement)
},
"findMatch": func(pattern, s string) string {
if s == "" {
return ""
}
return getCachedRegexp(pattern).FindString(s)
},
"findSubmatch": func(pattern, s string) string {
if s == "" {
return ""
}
regex := getCachedRegexp(pattern)
return itemAtIndexOrDefault(regex.FindStringSubmatch(s), 1, "")
},
"sortByString": func(key, order string, results []decoratedGJSONResult) []decoratedGJSONResult {
sort.Slice(results, func(a, b int) bool {
if order == "asc" {
return results[a].String(key) < results[b].String(key)
}
return results[a].String(key) > results[b].String(key)
})
return results
},
"sortByInt": func(key, order string, results []decoratedGJSONResult) []decoratedGJSONResult {
sort.Slice(results, func(a, b int) bool {
if order == "asc" {
return results[a].Int(key) < results[b].Int(key)
}
return results[a].Int(key) > results[b].Int(key)
})
return results
},
"sortByFloat": func(key, order string, results []decoratedGJSONResult) []decoratedGJSONResult {
sort.Slice(results, func(a, b int) bool {
if order == "asc" {
return results[a].Float(key) < results[b].Float(key)
}
return results[a].Float(key) > results[b].Float(key)
})
return results
},
"sortByTime": func(key, layout, order string, results []decoratedGJSONResult) []decoratedGJSONResult {
sort.Slice(results, func(a, b int) bool {
timeA := customAPIFuncParseTime(layout, results[a].String(key))
timeB := customAPIFuncParseTime(layout, results[b].String(key))
if order == "asc" {
return timeA.Before(timeB)
}
return timeA.After(timeB)
})
return results
},
"concat": func(items ...string) string {
return strings.Join(items, "")
},
"unique": func(key string, results []decoratedGJSONResult) []decoratedGJSONResult {
seen := make(map[string]struct{})
out := make([]decoratedGJSONResult, 0, len(results))
for _, result := range results {
val := result.String(key)
if _, ok := seen[val]; !ok {
seen[val] = struct{}{}
out = append(out, result)
}
}
return out
},
}
for key, value := range globalTemplateFunctions {
if _, exists := funcs[key]; !exists {
funcs[key] = value
}
}
return funcs
}()
func customAPIFuncParseTime(layout, value string) time.Time {
switch strings.ToLower(layout) {
case "unix":
asInt, err := strconv.ParseInt(value, 10, 64)
if err != nil {
return time.Unix(0, 0)
}
return time.Unix(asInt, 0)
case "rfc3339":
layout = time.RFC3339
case "rfc3339nano":
layout = time.RFC3339Nano
case "datetime":
layout = time.DateTime
case "dateonly":
layout = time.DateOnly
}
parsed, err := time.Parse(layout, value)
if err != nil {
return time.Unix(0, 0)
}
return parsed
}