From 901939bd96b38bcc6f4023d2c7075356153a6c8f Mon Sep 17 00:00:00 2001
From: Junegunn Choi <junegunn.c@gmail.com>
Date: Mon, 18 Sep 2023 00:51:40 +0900
Subject: [PATCH] Add support for limit and offset parameters for GET /
 endpoint

Related #3372
---
 src/server.go   | 40 +++++++++++++++++++++++++++++++++++++---
 src/terminal.go | 18 +++++++++---------
 2 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/src/server.go b/src/server.go
index 3698015..8fc605a 100644
--- a/src/server.go
+++ b/src/server.go
@@ -8,11 +8,23 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
 )
 
+var getRegex *regexp.Regexp
+
+func init() {
+	getRegex = regexp.MustCompile(`^GET /(?:\?([a-z0-9=&]+))? HTTP`)
+}
+
+type getParams struct {
+	limit  int
+	offset int
+}
+
 const (
 	crlf             = "\r\n"
 	httpOk           = "HTTP/1.1 200 OK" + crlf
@@ -117,9 +129,9 @@ func (server *httpServer) handleHttpRequest(conn net.Conn) string {
 		text := scanner.Text()
 		switch section {
 		case 0:
-			// TODO: Parameter support e.g. "GET /?limit=100 HTTP"
-			if strings.HasPrefix(text, "GET / HTTP") {
-				server.actionChannel <- []*action{{t: actResponse}}
+			getMatch := getRegex.FindStringSubmatch(text)
+			if len(getMatch) > 0 {
+				server.actionChannel <- []*action{{t: actResponse, a: getMatch[1]}}
 				response := <-server.responseChannel
 				return good(response)
 			} else if !strings.HasPrefix(text, "POST / HTTP") {
@@ -175,3 +187,25 @@ func (server *httpServer) handleHttpRequest(conn net.Conn) string {
 	server.actionChannel <- actions
 	return httpOk
 }
+
+func parseGetParams(query string) getParams {
+	params := getParams{limit: 100, offset: 0}
+	for _, pair := range strings.Split(query, "&") {
+		parts := strings.SplitN(pair, "=", 2)
+		if len(parts) == 2 {
+			switch parts[0] {
+			case "limit":
+				val, err := strconv.Atoi(parts[1])
+				if err == nil {
+					params.limit = val
+				}
+			case "offset":
+				val, err := strconv.Atoi(parts[1])
+				if err == nil {
+					params.offset = val
+				}
+			}
+		}
+	}
+	return params
+}
diff --git a/src/terminal.go b/src/terminal.go
index 1d8b55b..3a8c773 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -152,6 +152,7 @@ type StatusItem struct {
 
 type Status struct {
 	Reading    bool         `json:"reading"`
+	Progress   int          `json:"progress"`
 	Query      string       `json:"query"`
 	Position   int          `json:"position"`
 	Sort       bool         `json:"sort"`
@@ -3022,7 +3023,7 @@ func (t *Terminal) Loop() {
 			switch a.t {
 			case actIgnore:
 			case actResponse:
-				t.serverOutputChan <- t.dumpStatus()
+				t.serverOutputChan <- t.dumpStatus(parseGetParams(a.a))
 			case actBecome:
 				valid, list := t.buildPlusList(a.a, false)
 				if valid {
@@ -3802,18 +3803,16 @@ func (t *Terminal) dumpItem(i *Item) StatusItem {
 	}
 }
 
-const dumpItemLimit = 100 // TODO: Make configurable via GET parameter
-
-func (t *Terminal) dumpStatus() string {
+func (t *Terminal) dumpStatus(params getParams) string {
 	selectedItems := t.sortSelected()
-	selected := make([]StatusItem, util.Min(dumpItemLimit, len(selectedItems)))
-	for i, selectedItem := range selectedItems[:len(selected)] {
-		selected[i] = t.dumpItem(selectedItem.item)
+	selected := make([]StatusItem, util.Max(0, util.Min(params.limit, len(selectedItems)-params.offset)))
+	for i := range selected {
+		selected[i] = t.dumpItem(selectedItems[i+params.offset].item)
 	}
 
-	matches := make([]StatusItem, util.Min(dumpItemLimit, t.merger.Length()))
+	matches := make([]StatusItem, util.Max(0, util.Min(params.limit, t.merger.Length()-params.offset)))
 	for i := range matches {
-		matches[i] = t.dumpItem(t.merger.Get(i).item)
+		matches[i] = t.dumpItem(t.merger.Get(i + params.offset).item)
 	}
 
 	var current *StatusItem
@@ -3825,6 +3824,7 @@ func (t *Terminal) dumpStatus() string {
 
 	dump := Status{
 		Reading:    t.reading,
+		Progress:   t.progress,
 		Query:      string(t.input),
 		Position:   t.cy,
 		Sort:       t.sort,