// Copyright (c) 2026 Storm Dragon
// SPDX-License-Identifier: GPL-3.0-or-later

package prompt

import (
	"regexp"
	"strings"

	"git.stormux.org/storm/fenrir/internal/screen"
)

// Unlike Detector, ShellDetector excludes passwords, questions and completion
// messages. It observes raw screens, independently of application speech filters.
type ShellDetector struct {
	previous map[string]int
	terminal int
}

var shellPattern = regexp.MustCompile(`^(?:[$#>]|\[[^\r\n]+\]\s*[$#>]|[a-zA-Z0-9._-]+[$#>]|[a-zA-Z0-9._-]+@[^\s<>]+.*[$#>])\s*$`)

func (d *ShellDetector) Observe(next screen.Snapshot) bool {
	if !next.Active || next.Rows <= 0 || next.Cols <= 0 || len(next.Cells) != next.Rows*next.Cols {
		return false
	}
	counts := make(map[string]int)
	for row := range next.Rows {
		counts[strings.TrimSpace(next.Text(row))]++
	}
	text := ""
	if next.Y >= 0 && next.Y < next.Rows {
		text = strings.TrimSpace(next.Text(next.Y))
	}
	fresh := d.previous != nil && d.terminal == next.Terminal && shellPattern.MatchString(text) && counts[text] > d.previous[text]
	d.previous, d.terminal = counts, next.Terminal
	return fresh
}