gitlink-cli/internal/client/pagination.go

94 lines
2.0 KiB
Go

package client
import (
"encoding/json"
"fmt"
"net/url"
"strconv"
)
// PaginateAll fetches all pages and returns combined results.
func (c *Client) PaginateAll(path string, params url.Values) ([]json.RawMessage, error) {
if params == nil {
params = url.Values{}
}
if params.Get("limit") == "" {
params.Set("limit", "50")
}
var all []json.RawMessage
page := 1
for {
params.Set("page", strconv.Itoa(page))
env, err := c.Get(path, params)
if err != nil {
return nil, err
}
if !env.OK {
return nil, fmt.Errorf("API error on page %d", page)
}
// Try to extract array from data
var items []json.RawMessage
switch data := env.Data.(type) {
case []interface{}:
for _, item := range data {
raw, _ := json.Marshal(item)
items = append(items, raw)
}
case map[string]interface{}:
arr, ok := listArray(data)
if !ok {
// Single object, not paginated
raw, _ := json.Marshal(data)
return []json.RawMessage{raw}, nil
}
for _, item := range arr {
raw, _ := json.Marshal(item)
items = append(items, raw)
}
}
if len(items) == 0 {
break
}
all = append(all, items...)
// Check if we got fewer items than limit
limit, _ := strconv.Atoi(params.Get("limit"))
if len(items) < limit {
break
}
page++
}
return all, nil
}
// listArray resolves the item array of one wrapped list page. GitLink wraps the
// array under the generic "data" key on some endpoints and under a
// resource-specific key on others ({"pulls":[...]}, {"issues":[...]},
// {"branches":[...]}, ...), so prefer "data" and otherwise accept the sole
// array-valued field. A map with no array field — or several, which is
// ambiguous — is not a list page, so ok is false.
func listArray(data map[string]interface{}) (arr []interface{}, ok bool) {
if d, isArr := data["data"].([]interface{}); isArr {
return d, true
}
for _, v := range data {
slice, isArr := v.([]interface{})
if !isArr {
continue
}
if ok {
return nil, false
}
arr, ok = slice, true
}
return arr, ok
}