#!/bin/bash

# shim system-level operations to allow for unit testing
function MkDir() { mkdir     "$@"; }
function Mv() { mv        "$@"; }
function Sleep() { sleep     "$@"; }
function SystemCtl() { systemctl "$@"; }

# Store commanded rpm as thermal set-point.
#
# Arg:
#   rpm - rpm set-point.
function CommandRpm() {
    printf '%d\n' "$1" > /etc/thermal.d/set-point
}

# Sweep or step rpm over range.
#
# Args:
#   start_rpm: start RPM value
#   stop_rpm: stop RPM value
#   num_steps: number of control steps; i.e., not including start.
#   dwell: dwell time at each point, in seconds
function RunRpmSteps() {
    local -i start_rpm=$1
    local -i stop_rpm=$2
    local -i num_steps=$3
    local -i dwell=$4

    # Rounding offset when dividing range into num_steps
    local -i h=$((num_steps / 2))

    # To avoid asymmetrical division behavior for negative numbers,
    # rearrange negative slope to positive slope running backward;
    # I.e., to run using loop variable p: {num_steps downto 0}.
    local -i rpm0=$((start_rpm))
    local -i range=$((stop_rpm - start_rpm))
    local -i s=1
    if ((range < 0)); then
        ((rpm0 = stop_rpm))
        ((range = -range))
        ((s = -1))
    fi

    echo "Running RPM from ${start_rpm} to ${stop_rpm} in ${num_steps} steps"
    CommandRpm "${start_rpm}"
    SystemCtl start phosphor-pid-control.service
    Sleep 60

    local i
    for ((i = 0; i <= num_steps; ++i)); do
        local -i p=$((s < 0 ? num_steps - i : i))
        local -i rpm=$((rpm0 + (range * p + h) / num_steps))
        echo "Setting RPM to ${rpm} and sleep ${dwell} seconds"
        CommandRpm "${rpm}"
        Sleep "${dwell}"
    done

    SystemCtl stop phosphor-pid-control.service
    Mv /tmp/swampd.log ~/"${start_rpm}_${stop_rpm}_${num_steps}_${dwell}.csv"
    echo "Done!!"
}

# Sweep and step fans from min to max and max to min.
#
# Args:
#   min_rpm: min RPM for the platform
#   max_rpm: max RPM for the platform
function main() {
    local min_rpm=$1
    local max_rpm=$2

    if ((min_rpm < 1 || max_rpm < min_rpm)); then
        echo "Invalid arguments. Usage: fan_rpm_loop_test.sh <MIN_RPM> <MAX_RPM>"
        return 1
    fi

    MkDir -p /etc/thermal.d/
    SystemCtl stop phosphor-pid-control.service

    RunRpmSteps "${min_rpm}" "${max_rpm}" 10 30
    RunRpmSteps "${max_rpm}" "${min_rpm}" 10 30
    RunRpmSteps "${min_rpm}" "${max_rpm}"  1 30
    RunRpmSteps "${max_rpm}" "${min_rpm}"  1 30
}

if [ "$0" = "${BASH_SOURCE[0]}" ]; then
    # not sourced, execute main function
    main "$@"
fi