package tools

import (
	"context"
	"encoding/json"
	"fmt"
	"path/filepath"
	"strings"
	"time"

	"agent-system-backend/internal/execenv"
	core "agent-system-core"
)

// envBroker 由组合根注入。未注入时 python_env 明确报错，不假装能 pip install。
var envBroker *execenv.Broker

// envApproval 在申请需要人批时写一张选择卡。空则只把 pending 文本回给模型。
var envApproval func(owner, conversationID, requestID, detail string) error

// SetEnvBroker 注入分层环境代理。
func SetEnvBroker(b *execenv.Broker) { envBroker = b }

// SetEnvApproval 注入审批卡写入。
func SetEnvApproval(fn func(owner, conversationID, requestID, detail string) error) {
	envApproval = fn
}

func registerPythonEnvTool(r *Registry) error {
	return r.Register(core.ToolDesc{
		Name: "python_env", Source: core.SourceBuiltin, Risk: "medium",
		Description: "向系统申请 Python 包，或查看本会话已经能用的环境。沙箱不能联网安装。action=status 查看基础层与本会话的层；action=request 申请包（packages）或登记工作区内的 wheel；白名单内的包会自动装好并在下一次 run_python 生效，其余会进入审批。action=wait 等待 requestId 结束。不要用 pip install。",
		Parameters: json.RawMessage(`{"type":"object","properties":{` +
			`"action":{"type":"string","enum":["status","request","wait"],"description":"status | request | wait"},` +
			`"packages":{"type":"array","items":{"type":"string"},"description":"包规格，如 pdfplumber 或 numpy==2.2.0"},` +
			`"reason":{"type":"string","description":"为什么需要这些包"},` +
			`"wheel":{"type":"string","description":"工作区内的 .whl 相对路径，上传的包需要审批"},` +
			`"request_id":{"type":"string","description":"wait 时的申请 ID"},` +
			`"timeout_sec":{"type":"integer","description":"wait 的秒数，默认 120"}}` +
			`,"required":["action"]}`),
	}, execPythonEnv)
}

func execPythonEnv(rc ToolExecCtx, args json.RawMessage) (string, error) {
	if err := execGate(rc); err != nil {
		return "", err
	}
	if envBroker == nil {
		return "", fmt.Errorf("python_env: 环境代理未配置（启动参数 execEnvRoot）")
	}
	var a struct {
		Action    string   `json:"action"`
		Packages  []string `json:"packages"`
		Reason    string   `json:"reason"`
		Wheel     string   `json:"wheel"`
		RequestID string   `json:"request_id"`
		TimeoutS  int      `json:"timeout_sec"`
	}
	if len(args) > 0 {
		if err := json.Unmarshal(args, &a); err != nil {
			return "", fmt.Errorf("python_env: bad args: %w", err)
		}
	}
	switch a.Action {
	case "status":
		return envBroker.StatusText(rc.ConversationID())
	case "wait":
		if strings.TrimSpace(a.RequestID) == "" {
			return "", fmt.Errorf("python_env: request_id required")
		}
		timeout := time.Duration(a.TimeoutS) * time.Second
		out, err := envBroker.Wait(execParentCtx(rc), a.RequestID, timeout)
		if err != nil {
			return "", err
		}
		raw, _ := json.Marshal(out)
		return string(raw), nil
	case "request":
		wheel := ""
		if strings.TrimSpace(a.Wheel) != "" {
			sandbox, err := execSandbox(rc)
			if err != nil {
				return "", err
			}
			wheel, err = filepath.Abs(filepath.Join(sandbox, a.Wheel))
			if err != nil {
				return "", err
			}
			if !strings.HasPrefix(wheel, sandbox+string(filepath.Separator)) {
				return "", fmt.Errorf("python_env: wheel must stay inside the workspace")
			}
		}
		out, err := envBroker.RequestPackages(execParentCtx(rc), rc.ConversationID(), rc.OwnerID(), a.Reason, a.Packages, wheel)
		if err != nil {
			return "", err
		}
		if out.Status == "pending_approval" && envApproval != nil {
			if err := envApproval(rc.OwnerID(), rc.ConversationID(), out.RequestID, out.Detail); err != nil {
				out.Detail += "；审批卡未写入：" + err.Error()
			}
		}
		raw, _ := json.Marshal(out)
		return string(raw), nil
	default:
		return "", fmt.Errorf("python_env: unknown action %q", a.Action)
	}
}

// ExecDoctor 用当前执行后端探针导入基础交付物库。依赖层已配置但导入失败时返回错误。
func ExecDoctor() error {
	bin, err := resolveInterpreter("python3")
	if err != nil {
		return err
	}
	dirs, _ := pythonPathFor("")
	mounts := append([]string{}, dirs...)
	if execPythonPrefix != "" {
		mounts = append(mounts, execPythonPrefix)
	}
	if execShimDir != "" {
		mounts = append(mounts, execShimDir)
	}
	return execenv.Doctor(context.Background(), bin, dirs, nil, ExecBackendName() == "sandbox", mounts)
}