#!/usr/bin/env bash

set -o errexit
set -o nounset

# Assert at least one and at most two arguments were passed.
if [[ $# -lt 1 || $# -gt 2 ]]; then
    echo "Error: ${0##*/} accepts 1 or 2 arguments" >&2
    echo "Usage:" >&2
    echo "    ${0##*/} edge" >&2
    echo "    ${0##*/} stable x.x.x" >&2
    exit 1
fi

release_channel="$1"

# Verify the release channel.
release_channel_regex="^(edge|stable)$"
if [[ ! $release_channel =~ $release_channel_regex ]]; then
    echo "Error: valid release channels: edge, stable"
    echo "Usage:"
    echo "    bin/create-release-tag edge"
    echo "    bin/create-release-tag stable 2.4.8"
    exit 1
fi

if [ "$release_channel" == "stable" ]; then
    if [ $# -ne 2 ]; then
        echo "Error: accepts 2 arguments"
        echo "Usage:"
        echo "    bin/create-release-tag stable 2.4.8"
        exit 1
    fi

    stable_tag="$2"

    # Verify the stable tag format.
    stable_tag_regex="^([0-9]+)\.([0-9]+)\.([0-9]+)$"
    if [[ ! $stable_tag =~ $stable_tag_regex ]]; then
        echo "Error: version reference incorrect"
        echo "Usage:"
        echo "    bin/create-release-tag stable 2.4.8"
        exit 1
    fi

    # Set the script global `release_tag` variable.
    release_tag="stable-$stable_tag"
fi

if [ "$release_channel" == "edge" ]; then
if [ $# -ne 1 ]; then
        echo "Error: accepts 1 argument"
        echo "Usage:"
        echo "    bin/create-release-tag edge"
        exit 1
    fi

    # Some awks on Linux do no support quantifiers in regex, so this regex is
    # explicit.
    edge_tag_regex="(edge)-([0-9][0-9])\.([0-9]|[0-9][0-9])\.([0-9]+)"
    url="https://run.linkerd.io/install-edge"

    # Get the current edge version.
    current_edge=$(curl -sL $url | awk -v tag_format="$edge_tag_regex" '$0 ~ tag_format')

    # Get the third and fourth groups of the regex; they are the month and
    # month minor values for the current edge version.
    current_mm=$(echo "$current_edge" | sed -n -E "s/.*$edge_tag_regex}$/\3/p")
    current_xx=$(echo "$current_edge" | sed -n -E "s/.*$edge_tag_regex}$/\4/p")

    yy=$(date +"%y")
    
    # Strip leading zero
    new_mm=$(date +"%-m")

    # If this is a new month, `new_xx` should be 1; otherwise increment it.
    if [ ! "$new_mm" == "$current_mm" ]; then
        new_xx="1"
    else
        new_xx=$((current_xx+1))
    fi

    # Set the script global `release_tag` variable.
    release_tag="edge-$yy.$new_mm.$new_xx"
fi

bindir=$( cd "${BASH_SOURCE[0]%/*}" && pwd )
# shellcheck source=_release.sh
tmp=$(. "$bindir"/_release.sh; extract_release_notes)

# Create a signed tag with the commit message.
git tag -s -F "$tmp" "$release_tag"

# Success message
echo "$release_tag tag created and signed."
echo ""
echo "tag: $release_tag"
echo ""
echo "To push tag, run:"
echo "    git push origin $release_tag"