// waitfor blocks until a shell condition holds — the agent-friendly
// replacement for hand-rolled poll loops that each need a fresh
// command approval. See doc/tool-parity.md §3.2.
package main

import (
	"flag"
	"fmt"
	"os"
	"os/exec"
	"strings"
	"time"

	"gitea.brasse-pc.eu/brasse/agent-tools/waitfor/wait"
)

var version = "dev"

const usage = `waitfor - block until a condition holds

Usage:
  waitfor --cmd "shell command" [--matches regex] [--interval 30s]
          [--timeout 20m] [--then "shell command"] [--verbose]
  waitfor version

The condition holds when --cmd exits 0 and (if given) its combined
output matches --matches. The first attempt runs immediately.

Exit codes: 0 condition met, 3 timeout, 1 error. The last command
output is printed either way, so the caller always sees the state.

Examples:
  waitfor --cmd "curl -sf https://gitea.brasse-pc.eu/api/healthz" --interval 30s --timeout 20m
  waitfor --cmd "ssh pi5-claude sudo claude-docker ps" --matches gitea --timeout 10m
  waitfor --cmd "test -f /tmp/done" --then 'notifyr send --msg "done!"'
`

func main() {
	if len(os.Args) >= 2 && (os.Args[1] == "version" || os.Args[1] == "--version" || os.Args[1] == "-v") {
		fmt.Println("waitfor", version)
		return
	}
	if len(os.Args) >= 2 && (os.Args[1] == "help" || os.Args[1] == "--help" || os.Args[1] == "-h") {
		fmt.Print(usage)
		return
	}
	fs := flag.NewFlagSet("waitfor", flag.ExitOnError)
	cmd := fs.String("cmd", "", "shell command to poll (required)")
	matches := fs.String("matches", "", "regex the output must match")
	interval := fs.Duration("interval", 10*time.Second, "time between attempts")
	timeout := fs.Duration("timeout", 10*time.Minute, "total time budget")
	then := fs.String("then", "", "shell command to run when the condition is met")
	verbose := fs.Bool("verbose", false, "log every attempt to stderr")
	fs.Usage = func() { fmt.Fprint(os.Stderr, usage) }
	fs.Parse(os.Args[1:])
	if *cmd == "" {
		fmt.Fprint(os.Stderr, usage)
		os.Exit(1)
	}

	res, err := wait.Wait(wait.Options{
		Cmd: *cmd, Matches: *matches, Interval: *interval, Timeout: *timeout, Verbose: *verbose,
	}, wait.ShellRunner, func(s string) { fmt.Fprintln(os.Stderr, "waitfor: "+s) })
	if err != nil {
		fmt.Fprintln(os.Stderr, "waitfor:", err)
		os.Exit(1)
	}

	if out := strings.TrimRight(res.LastOut, "\n"); out != "" {
		fmt.Println(out)
	}
	if !res.Met {
		fmt.Fprintf(os.Stderr, "waitfor: timeout after %s (%d attempts, last exit %d)\n",
			res.Elapsed.Round(time.Second), res.Attempts, res.LastExit)
		os.Exit(3)
	}
	fmt.Fprintf(os.Stderr, "waitfor: condition met after %s (%d attempts)\n",
		res.Elapsed.Round(time.Millisecond), res.Attempts)
	if *then != "" {
		t := exec.Command("sh", "-c", *then)
		t.Stdout, t.Stderr = os.Stdout, os.Stderr
		if err := t.Run(); err != nil {
			fmt.Fprintf(os.Stderr, "waitfor: --then command failed: %v\n", err)
		}
	}
}