// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/extensions/corrupted_extension_reinstaller.h"

#include "base/functional/bind.h"
#include "base/logging.h"
#include "base/metrics/histogram_functions.h"
#include "base/task/single_thread_task_runner.h"
#include "chrome/browser/extensions/corrupted_extension_reinstaller_factory.h"
#include "chrome/browser/extensions/external_provider_manager.h"
#include "content/public/browser/browser_context.h"
#include "extensions/buildflags/buildflags.h"

static_assert(BUILDFLAG(ENABLE_EXTENSIONS_CORE));

namespace extensions {

namespace {

CorruptedExtensionReinstaller::ReinstallCallback* g_reinstall_action_for_test =
    nullptr;

const net::BackoffEntry::Policy kCorruptedReinstallBackoffPolicy = {
    // num_errors_to_ignore
    1,

    // initial_delay_ms (note that we set 'always_use_initial_delay' to false
    // below)
    100,

    // multiply_factor
    2,

    // jitter_factor
    0.1,

    // maximum_backoff_ms (30 minutes)
    1000 * 60 * 30,

    // entry_lifetime_ms (6 hours)
    1000 * 60 * 60 * 6,

    // always_use_initial_delay
    false,
};

}  // namespace

// static
CorruptedExtensionReinstaller* CorruptedExtensionReinstaller::Get(
    content::BrowserContext* context) {
  return CorruptedExtensionReinstallerFactory::GetInstance()
      ->GetForBrowserContext(context);
}

CorruptedExtensionReinstaller::CorruptedExtensionReinstaller(
    content::BrowserContext* context)
    : context_(context), backoff_entry_(&kCorruptedReinstallBackoffPolicy) {}

CorruptedExtensionReinstaller::~CorruptedExtensionReinstaller() = default;

// static
void CorruptedExtensionReinstaller::set_reinstall_action_for_test(
    ReinstallCallback* action) {
  g_reinstall_action_for_test = action;
}

void CorruptedExtensionReinstaller::RecordPolicyReinstallReason(
    PolicyReinstallReason reason_for_uma) {
  base::UmaHistogramEnumeration("Extensions.CorruptPolicyExtensionDetected3",
                                reason_for_uma);
}

void CorruptedExtensionReinstaller::ExpectReinstallForCorruption(
    const ExtensionId& id,
    std::optional<PolicyReinstallReason> reason_for_uma,
    mojom::ManifestLocation manifest_location_for_uma) {
  if (expected_reinstalls_.contains(id)) {
    return;
  }
  expected_reinstalls_[id] = base::TimeTicks::Now();
  if (reason_for_uma)
    RecordPolicyReinstallReason(*reason_for_uma);
}

void CorruptedExtensionReinstaller::MarkResolved(const ExtensionId& id) {
  if (!expected_reinstalls_.contains(id)) {
    return;
  }

  base::TimeDelta latency = base::TimeTicks::Now() - expected_reinstalls_[id];
  base::UmaHistogramLongTimes("Extensions.CorruptPolicyExtensionResolved",
                              latency);
  LOG(ERROR) << "Corrupted extension " << id << " reinstalled with latency "
             << latency;
  expected_reinstalls_.erase(id);
}

bool CorruptedExtensionReinstaller::IsReinstallForCorruptionExpected(
    const ExtensionId& id) const {
  return expected_reinstalls_.contains(id);
}

bool CorruptedExtensionReinstaller::HasAnyReinstallForCorruption() const {
  return !expected_reinstalls_.empty();
}

const std::map<ExtensionId, base::TimeTicks>&
CorruptedExtensionReinstaller::GetExpectedReinstalls() const {
  return expected_reinstalls_;
}

void CorruptedExtensionReinstaller::NotifyExtensionDisabledDueToCorruption() {
  ScheduleNextReinstallAttempt();
}

void CorruptedExtensionReinstaller::Shutdown() {
  // Cancels already-scheduled attempts, if any, for a smoother shutdown, by
  // invalidating weak pointers stored in postponed tasks.
  weak_factory_.InvalidateWeakPtrs();
}

void CorruptedExtensionReinstaller::Fire() {
  scheduled_fire_pending_ = false;
  // If there's nothing to repair, then bail out.
  if (!HasAnyReinstallForCorruption())
    return;

  ExternalProviderManager::Get(context_)->CheckForExternalUpdates();
  ScheduleNextReinstallAttempt();
}

base::TimeDelta CorruptedExtensionReinstaller::GetNextFireDelay() {
  backoff_entry_.InformOfRequest(false);
  return backoff_entry_.GetTimeUntilRelease();
}

void CorruptedExtensionReinstaller::ScheduleNextReinstallAttempt() {
  if (scheduled_fire_pending_)
    return;

  scheduled_fire_pending_ = true;
  base::TimeDelta reinstall_delay = GetNextFireDelay();
  base::OnceClosure callback = base::BindOnce(
      &CorruptedExtensionReinstaller::Fire, weak_factory_.GetWeakPtr());
  if (g_reinstall_action_for_test) {
    g_reinstall_action_for_test->Run(std::move(callback), reinstall_delay);
  } else {
    base::SingleThreadTaskRunner::GetCurrentDefault()->PostDelayedTask(
        FROM_HERE, std::move(callback), reinstall_delay);
  }
}

}  // namespace extensions