package main

import (
	"context"
	"fmt"
	"log/slog"
	"strings"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/exec"
)

// terminalToolName 是 exec/terminal 工具的注册名。
const terminalToolName = "terminal"

// terminalTool 是 sdk.Tool，通过基于授权的 exec 沙箱（exec.Provider）运行命令。
// 即使沙箱关闭它也会被注册：此时 Execute 返回 exec.ErrExecutionDisabled，因此
// agent 只有在主人显式启用沙箱后才获得执行代码的能力（默认关闭）。
type terminalTool struct {
	prov exec.Provider
	log  *slog.Logger
}

// Name 返回工具标识符。
func (t *terminalTool) Name() string { return terminalToolName }

// Description 说明工具做什么。
func (t *terminalTool) Description() string {
	return "Run a terminal command through the sandboxed exec provider and return its stdout, stderr and exit code."
}

// Parameters 返回输入 JSON Schema。
func (t *terminalTool) Parameters() (map[string]any, error) {
	return map[string]any{
		"type": "object",
		"properties": map[string]any{
			"command": map[string]any{
				"type":        "string",
				"description": "The command line to run; split into argv by whitespace (no shell interpretation).",
			},
			"workdir": map[string]any{
				"type":        "string",
				"description": "Optional working directory, confined to an allowed sandbox root.",
			},
			"timeout": map[string]any{
				"type":        "number",
				"description": "Optional timeout in seconds (default 30).",
			},
		},
		"required": []any{"command"},
	}, nil
}

// Execute 通过 exec provider 运行命令并返回结果。沙箱关闭时 provider 返回
// exec.ErrExecutionDisabled，分发器会把它包装成可安全回喂给 LLM 的工具错误。
func (t *terminalTool) Execute(ctx context.Context, args any) (any, error) {
	m, ok := args.(map[string]any)
	if !ok {
		return nil, fmt.Errorf("terminal: args must be an object")
	}
	cmd, _ := m["command"].(string)
	argv := strings.Fields(cmd)
	if len(argv) == 0 {
		return nil, fmt.Errorf("terminal: command is required")
	}
	if t.log != nil {
		t.log.Debug("terminal tool invoked", "cmd", strings.Join(argv, " "))
	}
	req := exec.ExecRequest{Command: argv, Timeout: timeoutArg(m["timeout"])}
	if wd, ok := m["workdir"].(string); ok {
		req.WorkDir = wd
	}
	res, err := t.prov.Execute(ctx, req)
	if err != nil {
		return nil, err
	}
	return map[string]any{
		"stdout":    res.Stdout,
		"stderr":    res.Stderr,
		"exit":      res.ExitCode,
		"truncated": res.Truncated,
	}, nil
}

// timeoutArg 把可选的 timeout 参数（秒）转换为 duration。缺失或非正值返回 0，
// 由 provider 应用自己的默认值。
func timeoutArg(v any) time.Duration {
	switch n := v.(type) {
	case float64:
		if n > 0 {
			return time.Duration(n * float64(time.Second))
		}
	case int:
		if n > 0 {
			return time.Duration(n) * time.Second
		}
	}
	return 0
}

// wireTerminalTool 向分发器注册 terminal 工具，使 agent 能发出沙箱内终端命令。
// 未接入 exec provider 时它只告警并空操作，以保证调用方安全。
func (a *app) wireTerminalTool() {
	log := logger.WithSource(a.log, "cmd/cyrene")
	if a.execProv == nil {
		log.Warn("terminal tool skipped: no exec provider")
		return
	}
	if err := a.dispatcher.Register(&terminalTool{
		prov: a.execProv,
		log:  logger.WithSource(a.log, "cmd/cyrene"),
	}); err != nil {
		log.Warn("terminal tool register skipped", "error", err)
		return
	}
	log.Info("terminal tool registered", "sandbox_enabled", a.cfg.ExecSandbox.Enabled)
}