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

package webscripts

import (
	"regexp"
	"sort"
	"strconv"
	"strings"
	"time"
)

const steamNotificationDelay = 500 * time.Millisecond

var steamRelativeTime = regexp.MustCompile(`(?i)^(?:just now|now|\d+\s+(?:second|minute|hour|day|week|month|year)s?\s+ago)$`)

var steamShaderProgress = regexp.MustCompile(`^Processing Vulkan shaders \((\d{1,3})%\)$`)

// ShaderProgress recognizes Steam's English shader status, which Chromium
// exposes as static text rather than an AT-SPI progress bar. Match the leaf
// only: containing sections repeat this text alongside dialog controls.
func ShaderProgress(processName, eventType, role, name string) (float64, bool) {
	if MatchProcess(processName) != Steam || eventType != "object:property-change:accessible-name" || role != "static" {
		return 0, false
	}
	match := steamShaderProgress.FindStringSubmatch(strings.TrimSpace(name))
	if match == nil {
		return 0, false
	}
	percentage, err := strconv.Atoi(match[1])
	return float64(percentage), err == nil && percentage <= 100
}

// NotificationRoot mirrors Python's Steam root selection: notification/alert
// ancestors take precedence over inherited live-region attributes on a leaf.
// Candidates are ordered from the event source towards its application root.
func NotificationRoot(candidates []NotificationCandidate) int {
	for index, candidate := range candidates {
		if candidate.Role == "notification" || candidate.Role == "alert" {
			return index
		}
	}
	for index, candidate := range candidates {
		if candidate.Live == "assertive" || candidate.Live == "polite" ||
			candidate.ContainerLive == "assertive" || candidate.ContainerLive == "polite" {
			return index
		}
	}
	return -1
}

type notificationKey struct{ busName, rootPath string }
type pendingNotification struct {
	text          string
	windowPath    string
	timestampOnly bool
	deadline      time.Time
}
type completedNotification struct {
	text string
	at   time.Time
}
type steamNotifications struct {
	pending map[notificationKey]pendingNotification
	last    map[string]completedNotification
}

func normalize(text string) string {
	return strings.Join(strings.Fields(strings.ReplaceAll(text, "\ufffc", "")), " ")
}

func contains(text, other string) bool {
	text, other = strings.ToLower(text), strings.ToLower(other)
	if len(other) < 4 {
		return text == other
	}
	return strings.Contains(text, other)
}

func appendTimestamp(text, timestamp string) string {
	if strings.ContainsAny(text[len(text)-1:], ".!?") {
		return text + " " + timestamp
	}
	return text + ". " + timestamp
}

func (steam *steamNotifications) queue(message Notification, now time.Time) []string {
	text := normalize(message.Text)
	if text == "" {
		return nil
	}
	if steam.pending == nil {
		steam.pending = make(map[notificationKey]pendingNotification)
	}
	key := notificationKey{message.BusName, message.RootPath}
	pending, exists := steam.pending[key]
	timestamp := steamRelativeTime.MatchString(text)
	var messages []string
	if exists {
		switch {
		case text == pending.text:
			return nil
		case timestamp:
			if pending.timestampOnly {
				pending.text = text
			} else {
				pending.text = appendTimestamp(pending.text, text)
			}
		case pending.timestampOnly:
			pending.text = appendTimestamp(text, pending.text)
			pending.timestampOnly = false
		case contains(text, pending.text):
			pending.text = text
		case contains(pending.text, text):
			return nil
		default:
			pending.text = normalize(pending.text + " " + text)
		}
	} else {
		// Bound outstanding roots without merging independent toasts. Finish
		// the oldest root if a provider emits an excessive burst.
		if len(steam.pending) >= 32 {
			oldest := steam.orderedKeys()[0]
			messages = steam.complete(oldest, now)
		}
		pending = pendingNotification{text: text, timestampOnly: timestamp}
	}
	// Bound accumulated fragments as well as each native capture.
	characters := []rune(pending.text)
	if len(characters) > 4096 {
		pending.text = string(characters[:4096])
	}
	pending.deadline = now.Add(steamNotificationDelay)
	pending.windowPath = message.WindowPath
	steam.pending[key] = pending
	return messages
}

func (steam *steamNotifications) orderedKeys() []notificationKey {
	keys := make([]notificationKey, 0, len(steam.pending))
	for key := range steam.pending {
		keys = append(keys, key)
	}
	sort.Slice(keys, func(first, second int) bool {
		left, right := keys[first], keys[second]
		if steam.pending[left].deadline.Equal(steam.pending[right].deadline) {
			if left.busName == right.busName {
				return left.rootPath < right.rootPath
			}
			return left.busName < right.busName
		}
		return steam.pending[left].deadline.Before(steam.pending[right].deadline)
	})
	return keys
}

func (steam *steamNotifications) complete(key notificationKey, now time.Time) []string {
	pending := steam.pending[key]
	delete(steam.pending, key)
	if pending.timestampOnly {
		return nil
	}
	last := steam.last[key.busName]
	if last.text == pending.text && now.Sub(last.at) < time.Second {
		return nil
	}
	if steam.last == nil {
		steam.last = make(map[string]completedNotification)
	}
	for busName, completed := range steam.last {
		if now.Sub(completed.at) >= time.Second {
			delete(steam.last, busName)
		}
	}
	if len(steam.last) >= 64 {
		clear(steam.last)
	}
	steam.last[key.busName] = completedNotification{text: pending.text, at: now}
	return []string{"Steam: " + pending.text}
}

func (steam *steamNotifications) flush(now time.Time) []string {
	var messages []string
	for _, key := range steam.orderedKeys() {
		if !steam.pending[key].deadline.After(now) {
			messages = append(messages, steam.complete(key, now)...)
		}
	}
	return messages
}

func (steam *steamNotifications) deadline() time.Time {
	keys := steam.orderedKeys()
	if len(keys) == 0 {
		return time.Time{}
	}
	return steam.pending[keys[0]].deadline
}