//
//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
//

package tool

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"

	einotool "github.com/cloudwego/eino/components/tool"
	"github.com/cloudwego/eino/compose"
	"github.com/cloudwego/eino/flow/agent/react"
	"github.com/cloudwego/eino/schema"
)

func TestDuckDuckGo_BuildSearchURL(t *testing.T) {
	got := buildDuckDuckGoSearchURL("rag flow", 7)
	u, err := url.Parse(got)
	if err != nil {
		t.Fatalf("url.Parse(%q): %v", got, err)
	}
	if u.Host != "duckduckgo.com" {
		t.Errorf("host = %q, want duckduckgo.com", u.Host)
	}
	if u.Path != "/html/" {
		t.Errorf("path = %q, want /html/", u.Path)
	}
	q := u.Query()
	if q.Get("q") != "rag flow" {
		t.Errorf("q = %q, want rag flow", q.Get("q"))
	}
	if q.Get("dc") != "8" {
		t.Errorf("dc = %q, want 8", q.Get("dc"))
	}
	if got := q.Get("vqd"); got != "" {
		t.Errorf("vqd = %q, want omitted", got)
	}
}

func TestDuckDuckGo_BuildNewsURL(t *testing.T) {
	got := buildDuckDuckGoNewsURL("rag flow", 3)
	u, err := url.Parse(got)
	if err != nil {
		t.Fatalf("url.Parse(%q): %v", got, err)
	}
	if u.Path != "/news.js" {
		t.Errorf("path = %q, want /news.js", u.Path)
	}
	q := u.Query()
	if q.Get("o") != "json" {
		t.Fatalf("o = %q, want json", q.Get("o"))
	}
	if q.Get("l") != "wt-wt" {
		t.Fatalf("l = %q, want wt-wt", q.Get("l"))
	}
	if q.Get("dc") != "3" {
		t.Errorf("dc = %q, want 3", q.Get("dc"))
	}
}

func TestDuckDuckGo_BuildNewsURLWithVQD(t *testing.T) {
	got := buildDuckDuckGoNewsURLWithVQD("rag flow", 3, "vqd-1")
	u, err := url.Parse(got)
	if err != nil {
		t.Fatalf("url.Parse(%q): %v", got, err)
	}
	q := u.Query()
	if q.Get("vqd") != "vqd-1" {
		t.Fatalf("vqd = %q, want vqd-1", q.Get("vqd"))
	}
	if q.Get("u") != "bing" {
		t.Fatalf("u = %q, want bing", q.Get("u"))
	}
}

func TestDuckDuckGo_ParseGeneralResults(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		_, _ = w.Write([]byte(`<!doctype html><html><body>
			<div class="results">
				<div class="result">
					<a class="result__a" href="//duckduckgo.com/l/?uddg=https%3A%2F%2Fragflow.io">RAGFlow</a>
					<a class="result__snippet">Open source RAG engine</a>
				</div>
				<div class="result">
					<a class="result__a" href="https://github.com/infiniflow/ragflow">GitHub</a>
					<div class="result__snippet">Source code repository</div>
				</div>
			</div>
		</body></html>`))
	}))
	defer srv.Close()

	prevSearch := duckduckgoSearchEndpoint
	duckduckgoSearchEndpoint = srv.URL
	t.Cleanup(func() { duckduckgoSearchEndpoint = prevSearch })

	tool := NewDuckDuckGoTool()
	out, err := tool.InvokableRun(context.Background(), `{"query":"ragflow","top_n":5}`)
	if err != nil {
		t.Fatalf("InvokableRun: %v", err)
	}

	var env duckduckgoEnvelope
	if jerr := json.Unmarshal([]byte(out), &env); jerr != nil {
		t.Fatalf("output is not valid JSON: %v (raw=%s)", jerr, out)
	}
	if env.Error != "" {
		t.Errorf("Error = %q, want empty", env.Error)
	}
	if len(env.Results) != 2 {
		t.Fatalf("Results len = %d, want 2", len(env.Results))
	}
	if env.Results[0].Title != "RAGFlow" {
		t.Errorf("Results[0].Title = %q, want RAGFlow", env.Results[0].Title)
	}
	if env.Results[0].URL != "https://ragflow.io" {
		t.Errorf("Results[0].URL = %q, want https://ragflow.io", env.Results[0].URL)
	}
	if env.Results[0].Body != "Open source RAG engine" {
		t.Errorf("Results[0].Body = %q, want Open source RAG engine", env.Results[0].Body)
	}
}

func TestDuckDuckGo_ParseNewsResults(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/bootstrap":
			w.Header().Set("Content-Type", "text/html; charset=utf-8")
			_, _ = w.Write([]byte(`<!doctype html><html><head><script>var x=""; var vqd="test-vqd-1";</script></head><body></body></html>`))
		case "/news.js":
			if got := r.URL.Query().Get("vqd"); got != "test-vqd-1" {
				t.Fatalf("vqd = %q, want test-vqd-1", got)
			}
			w.Header().Set("Content-Type", "application/json")
			_, _ = w.Write([]byte(`{
				"results": [
					{"title":"Story One","url":"https://news.example.com/story-1","excerpt":"Breaking update one"},
					{"title":"Story Two","url":"https://news.example.com/story-2","excerpt":"Breaking &amp; update two"}
				]
			}`))
		default:
			t.Fatalf("unexpected path: %s", r.URL.Path)
		}
	}))
	defer srv.Close()

	prevNews := duckduckgoNewsEndpoint
	prevBootstrap := duckduckgoNewsBootstrapEndpoint
	duckduckgoNewsEndpoint = srv.URL + "/news.js"
	duckduckgoNewsBootstrapEndpoint = srv.URL + "/bootstrap"
	t.Cleanup(func() { duckduckgoNewsEndpoint = prevNews })
	t.Cleanup(func() { duckduckgoNewsBootstrapEndpoint = prevBootstrap })

	tool := NewDuckDuckGoTool()
	out, err := tool.InvokableRun(context.Background(), `{"query":"ragflow","channel":"news","top_n":1}`)
	if err != nil {
		t.Fatalf("InvokableRun: %v", err)
	}

	var env duckduckgoEnvelope
	if jerr := json.Unmarshal([]byte(out), &env); jerr != nil {
		t.Fatalf("output is not valid JSON: %v", jerr)
	}
	if len(env.Results) != 1 {
		t.Fatalf("Results len = %d, want 1", len(env.Results))
	}
	if env.Results[0].Title != "Story One" {
		t.Errorf("Results[0].Title = %q, want Story One", env.Results[0].Title)
	}
	if env.Results[0].URL != "https://news.example.com/story-1" {
		t.Errorf("Results[0].URL = %q, want https://news.example.com/story-1", env.Results[0].URL)
	}
	if env.Results[0].Body != "Breaking update one" {
		t.Errorf("Results[0].Body = %q, want Breaking update one", env.Results[0].Body)
	}
}

func TestDuckDuckGo_DefaultChannelUsesGeneralSearch(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if got := r.URL.Path; got != "/" {
			// keep old behavior impossible to hit if search endpoint override works incorrectly
		}
		if got := r.URL.Query().Get("o"); got != "" {
			t.Fatalf("o = %q, want empty for general search html endpoint", got)
		}
		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		_, _ = w.Write([]byte(`<!doctype html><html><body>
			<div class="result"><a class="result__a" href="https://n.example/a">A</a></div>
		</body></html>`))
	}))
	defer srv.Close()

	prevSearch := duckduckgoSearchEndpoint
	duckduckgoSearchEndpoint = srv.URL
	t.Cleanup(func() { duckduckgoSearchEndpoint = prevSearch })

	tool := NewDuckDuckGoTool()
	_, err := tool.InvokableRun(context.Background(), `{"query":"ragflow"}`)
	if err != nil {
		t.Fatalf("InvokableRun: %v", err)
	}
}

func TestDuckDuckGo_Info(t *testing.T) {
	tool := NewDuckDuckGoTool()
	info, err := tool.Info(context.Background())
	if err != nil {
		t.Fatalf("Info: %v", err)
	}
	if info.Name != "duckduckgo" {
		t.Errorf("Name = %q, want duckduckgo", info.Name)
	}
	if !strings.Contains(info.Desc, "DuckDuckGo") {
		t.Errorf("Desc = %q, want to mention DuckDuckGo", info.Desc)
	}
	if info.ParamsOneOf == nil {
		t.Fatal("ParamsOneOf = nil, want schema definition")
	}
	schema, err := info.ParamsOneOf.ToJSONSchema()
	if err != nil {
		t.Fatalf("ToJSONSchema: %v", err)
	}
	raw, err := json.Marshal(schema)
	if err != nil {
		t.Fatalf("marshal params schema: %v", err)
	}
	params := string(raw)
	if !strings.Contains(params, `"channel"`) {
		t.Fatalf("schema missing channel param: %s", params)
	}
	if strings.Contains(params, `"top_n"`) {
		t.Fatalf("schema should not expose top_n param: %s", params)
	}
}

func TestDuckDuckGo_RequiresQuery(t *testing.T) {
	tool := NewDuckDuckGoTool()
	_, err := tool.InvokableRun(context.Background(), `{"query":""}`)
	if err == nil {
		t.Fatal("expected error for empty query")
	}
	if !strings.Contains(err.Error(), "query") {
		t.Errorf("err = %v, want to mention query", err)
	}
}

func TestDuckDuckGo_RealReactAgent_ExecutesTool(t *testing.T) {
	var hitCount int
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		hitCount++
		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		_, _ = w.Write([]byte(`<!doctype html><html><body>
			<div class="result">
				<a class="result__a" href="https://ragflow.io">RAGFlow</a>
				<div class="result__snippet">RAGFlow is an open-source RAG engine.</div>
			</div>
		</body></html>`))
	}))
	defer srv.Close()

	prevSearch := duckduckgoSearchEndpoint
	duckduckgoSearchEndpoint = srv.URL
	t.Cleanup(func() { duckduckgoSearchEndpoint = prevSearch })

	realTool := NewDuckDuckGoTool()

	mdl := newReactScriptedModel(
		"duckduckgo",
		`{"query":"ragflow"}`,
		"RAGFlow is an open-source RAG engine.",
	)

	agent, err := react.NewAgent(context.Background(), &react.AgentConfig{
		ToolCallingModel: mdl,
		ToolsConfig: compose.ToolsNodeConfig{
			Tools: []einotool.BaseTool{realTool},
		},
		MaxStep: 5,
	})
	if err != nil {
		t.Fatalf("react.NewAgent: %v", err)
	}

	out, err := agent.Generate(context.Background(), []*schema.Message{
		schema.UserMessage("What is RAGFlow?"),
	})
	if err != nil {
		t.Fatalf("agent.Generate: %v", err)
	}
	if got, want := out.Content, "RAGFlow is an open-source RAG engine."; got != want {
		t.Errorf("Content = %q, want %q", got, want)
	}
	if mdl.turn != 2 {
		t.Errorf("Generate called %d times, want 2 (tool_call + final)", mdl.turn)
	}
	if len(mdl.boundTools) != 1 || mdl.boundTools[0].Name != "duckduckgo" {
		names := make([]string, 0, len(mdl.boundTools))
		for _, ti := range mdl.boundTools {
			names = append(names, ti.Name)
		}
		t.Errorf("tools bound to model = %v, want [duckduckgo]", names)
	}
	if len(mdl.rounds) < 2 {
		t.Fatalf("only %d rounds captured, want >= 2", len(mdl.rounds))
	}
	var sawToolResult bool
	for _, msg := range mdl.rounds[1] {
		if msg.Role == schema.Tool && strings.Contains(msg.Content, "RAGFlow is an open-source RAG engine") {
			sawToolResult = true
			break
		}
	}
	if !sawToolResult {
		t.Errorf("round 2 input did not contain a ToolMessage carrying the upstream result")
	}
	if hitCount == 0 {
		t.Error("test server was never hit; the tool did not actually call the upstream")
	}
}
