/*
 * Copyright 2025 CloudWeGo Authors
 *
 * 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 main

import (
	"context"
	"log"
	"time"

	"github.com/cloudwego/eino/adk"
	"github.com/cloudwego/eino/components/tool"
	"github.com/cloudwego/eino/compose"

	"github.com/cloudwego/eino-examples/adk/common/model"
	"github.com/cloudwego/eino-examples/adk/common/prints"
	"github.com/cloudwego/eino-examples/adk/common/trace"
	"github.com/cloudwego/eino-examples/adk/intro/agent_with_summarization/summarization"
	"github.com/cloudwego/eino-examples/internal/logs"
)

const (
	summaryMaxTokensBefore = 10 * 1024
	summaryMaxTokensRecent = 2 * 1024
	agentMaxIterations     = 30
)

func main() {
	ctx := context.Background()

	a, err := newAgent(ctx)
	if err != nil {
		logs.Fatalf("create agent failed, err=%v", err)
	}

	traceCloseFn, startSpanFn := trace.AppendCozeLoopCallbackIfConfigured(ctx)
	defer traceCloseFn(ctx)

	runner := adk.NewRunner(ctx, adk.RunnerConfig{
		EnableStreaming: true, // you can disable streaming here
		Agent:           a,
	})

	query := `Write a very long report on the history of artificial intelligence.`
	ctx, endSpanFn := startSpanFn(ctx, "Agent", query)

	iter := runner.Query(ctx, query)

	var lastMessage adk.Message
	for {
		event, ok := iter.Next()
		if !ok {
			break
		}
		if event.Err != nil {
			log.Fatal(event.Err)
		}

		prints.Event(event)

		if event.Output != nil {
			if msg, _, getErr := adk.GetMessage(event); getErr == nil {
				lastMessage = msg
			}
		}

	}

	endSpanFn(ctx, lastMessage)

	// wait for all span to be ended
	time.Sleep(10 * time.Second)
}

func newAgent(ctx context.Context) (adk.Agent, error) {
	sumMW, err := summarization.New(ctx, &summarization.Config{
		Model:                      model.NewChatModel(),
		MaxTokensBeforeSummary:     summaryMaxTokensBefore,
		MaxTokensForRecentMessages: summaryMaxTokensRecent,
	})
	if err != nil {
		return nil, err
	}

	a, err := adk.NewChatModelAgent(ctx, &adk.ChatModelAgentConfig{
		Name:        "main_agent",
		Description: "A long-form report assistant",
		Instruction: `You are a long-form report writer working in ReAct mode.
Think step by step, call tools to expand content by repeating paragraphs, then synthesize a cohesive response.
one time call one tool, do not call multiple tools in one turn.
Each tool call should indicate the call number. After 20 tool calls, produce a final summary.`,
		Model:       model.NewChatModel(),
		Middlewares: []adk.AgentMiddleware{sumMW},
		ToolsConfig: adk.ToolsConfig{
			ToolsNodeConfig: compose.ToolsNodeConfig{
				Tools: []tool.BaseTool{
					NewRepeatSectionsTool(),
				},
			},
		},
		MaxIterations: agentMaxIterations,
	})
	if err != nil {
		return nil, err
	}
	return a, nil
}