package main

import (
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"io"
	"os"
	"time"

	"data-terminal-cloud/internal/agenteval"
)

func main() {
	os.Exit(run(os.Args[1:], os.Stdout, os.Stderr, time.Now))
}

func run(args []string, stdout, stderr io.Writer, now func() time.Time) int {
	flags := flag.NewFlagSet("agent-eval", flag.ContinueOnError)
	flags.SetOutput(stderr)
	suitePath := flags.String("suite", "", "评测集JSON路径")
	observationsPath := flags.String("observations", "", "脱敏观测结果JSON路径")
	outputPath := flags.String("out", "", "报告输出路径；省略时输出到stdout")
	reportRef := flags.String("report-ref", "", "登记到运营配置评测证据中的报告引用")
	if err := flags.Parse(args); err != nil {
		return 2
	}
	if *suitePath == "" || *observationsPath == "" || *reportRef == "" || flags.NArg() != 0 {
		fmt.Fprintln(stderr, "usage: agent-eval -suite <suite.json> -observations <observations.json> -report-ref <reference> [-out <report.json>]")
		return 2
	}

	var suite agenteval.Suite
	if err := decodeFile(*suitePath, &suite); err != nil {
		fmt.Fprintf(stderr, "读取评测集失败: %v\n", err)
		return 2
	}
	var observations agenteval.ObservationRun
	if err := decodeFile(*observationsPath, &observations); err != nil {
		fmt.Fprintf(stderr, "读取观测结果失败: %v\n", err)
		return 2
	}
	report, err := agenteval.Evaluate(suite, observations, now())
	if err != nil {
		fmt.Fprintf(stderr, "评测输入无效: %v\n", err)
		return 2
	}
	artifact, err := agenteval.NewArtifact(report, *reportRef)
	if err != nil {
		fmt.Fprintf(stderr, "报告引用无效: %v\n", err)
		return 2
	}
	encoded, err := json.MarshalIndent(artifact, "", "  ")
	if err != nil {
		fmt.Fprintf(stderr, "生成评测报告失败: %v\n", err)
		return 2
	}
	encoded = append(encoded, '\n')
	if *outputPath == "" {
		if _, err = stdout.Write(encoded); err != nil {
			fmt.Fprintf(stderr, "输出评测报告失败: %v\n", err)
			return 2
		}
	} else if err = os.WriteFile(*outputPath, encoded, 0o600); err != nil {
		fmt.Fprintf(stderr, "写入评测报告失败: %v\n", err)
		return 2
	} else {
		fmt.Fprintf(stdout, "%s：%s（%d/%d）\n", report.Result, *outputPath, report.Metrics.CasesPassed, report.Metrics.CasesTotal)
	}
	if report.Result != "PASSED" {
		return 1
	}
	return 0
}

func decodeFile(path string, target any) error {
	file, err := os.Open(path)
	if err != nil {
		return err
	}
	defer file.Close()
	decoder := json.NewDecoder(file)
	decoder.DisallowUnknownFields()
	if err = decoder.Decode(target); err != nil {
		return err
	}
	var trailing any
	if err = decoder.Decode(&trailing); !errors.Is(err, io.EOF) {
		if err == nil {
			return errors.New("JSON文件包含多个顶层值")
		}
		return err
	}
	return nil
}