#!/usr/bin/env bash
#
# Prepares the device for the macrobenchmark module, and takes it back afterwards.
#
#   ./tools/benchmark-fixture.sh            # create the folder, grant storage access
#   ./tools/benchmark-fixture.sh --remove   # delete the folder again
#
# Why this is a script rather than setup inside the benchmark: UiAutomation's executeShellCommand
# runs with the *test app's* uid, not the shell's, so it cannot write to /sdcard and cannot grant
# itself an app-op. The first version of the benchmark tried exactly that and failed with a
# RuntimeException from UiAutomationConnection, leaving no fixture and a hang. Through adb the same
# commands run as the shell user, which has the rights this needs.
#
# The folder is at the root of shared storage under a name that sorts before everything else, so the
# benchmark finds its row without scrolling.
set -euo pipefail

package=de.softwareapp_hb.filemanager
directory=/sdcard/AABenchmark
count=1000

# The size is a knob because the interesting question is how the browser scales: 1 000 files is what the
# benchmark uses by default, and 5 000 or 20 000 is the same run with a bigger folder:
#
#   ./tools/benchmark-fixture.sh --count 20000
#
# Creating is idempotent: a folder that already holds at least `--count` files is left alone, because
# building twenty thousand files through a phone's storage layer takes about half an hour and the fixture
# is worth keeping between runs. `--fresh` rebuilds it anyway.
if [ "${1:-}" = "--count" ]; then
    count=${2:?"--count needs a number"}
    case "$count" in
        ''|*[!0-9]*) echo "benchmark-fixture: --count needs a number, not '$count'" >&2; exit 2 ;;
    esac
    shift 2
fi

fresh=0
if [ "${1:-}" = "--fresh" ]; then
    fresh=1
    shift
fi

case "${1:-create}" in
    --remove)
        adb shell "rm -rf $directory"
        echo "benchmark-fixture: removed $directory"
        ;;
    create)
        existing=$(adb shell "ls $directory 2>/dev/null | wc -l" | tr -d '\r ')
        if [ "$fresh" -eq 0 ] && [ "${existing:-0}" -ge "$count" ]; then
            echo "benchmark-fixture: reusing $directory ($existing files, $count asked for)"
        else
            # One shell loop with builtin redirection: no fork per file, so a thousand files take a
            # moment rather than a minute.
            adb shell "rm -rf $directory; mkdir -p $directory; \
                i=0; while [ \$i -lt $count ]; do : > $directory/file-\$i.txt; i=\$((i+1)); done"
            echo "benchmark-fixture: $count files in $directory"
        fi
        # The benchmark build is not the debug build, so it starts with no storage grant; granting it
        # here is what lets the run be unattended. No `--uid`: that flag takes a uid, not a package
        # name, and passing a package there grants nothing while still reporting that something was
        # set — which is exactly the kind of half-truth that costs an afternoon. Re-granted even when the
        # fixture is reused, because a reinstall of the app clears its app-ops.
        adb shell "appops set $package MANAGE_EXTERNAL_STORAGE allow"
        echo "benchmark-fixture: storage granted to $package"
        ;;
    *)
        echo "usage: $0 [--remove]" >&2
        exit 2
        ;;
esac