#!/bin/bash

set -eo pipefail

GITEA_DOWNLOAD_PROJECT=${GITEA_DOWNLOAD_PROJECT}
GITEA_DOWNLOAD_ORG=${GITEA_DOWNLOAD_ORG}
GITEA_DOWNLOAD_BASE_URL=${GITEA_BASE_URL:-https://forge.cadoles.com}
GITEA_DOWNLOAD_USERNAME=${GITEA_DOWNLOAD_USERNAME}
GITEA_DOWNLOAD_PASSWORD=${GITEA_DOWNLOAD_PASSWORD}
GITEA_DOWNLOAD_RELEASE_NAME=${GITEA_DOWNLOAD_RELEASE_NAME:-latest}
GITEA_DOWNLOAD_TARGET_DIRECTORY=${GITEA_DOWNLOAD_TARGET_DIRECTORY:-gitea-dl}

function check_dependencies {
    assert_command_available 'curl'
    assert_command_available 'jq'
}

function assert_command_available {
    local command=$1
    local command_path=$(which $command)

    if [ -z "$command_path" ]; then
        echo "The '$command' command could not be found. Please install it before using this script." 1>&2
        exit 1
    fi
}

function check_environment {
    assert_environment GITEA_DOWNLOAD_PROJECT
    assert_environment GITEA_DOWNLOAD_ORG
    assert_environment GITEA_DOWNLOAD_BASE_URL
}

function source_env_file {
    if [ ! -f '.env' ]; then
        return 0
    fi
    set -o allexport
    source .env
    set +o allexport
}

function assert_environment {
    local name=$1
    local value=${!name}

    if [ -z "$value" ]; then
        echo "The $"$name" environment variable is empty." 1>&2
        exit 1
    fi
}

function ask_credentials {
    if [ -z "$GITEA_DOWNLOAD_USERNAME" ]; then
        echo -n "Username: "
        read GITEA_DOWNLOAD_USERNAME
        
    fi
    if [ -z "$GITEA_DOWNLOAD_PASSWORD" ]; then
        echo -n "Password: "
        stty -echo
        read GITEA_DOWNLOAD_PASSWORD
        stty echo 
        echo
    fi
}

function retrieve_release_name {
    if [ ! -z "$GITEA_DOWNLOAD_RELEASE_NAME" ]; then
        return
    fi

    echo -n "Release name: "
    read GITEA_DOWNLOAD_RELEASE_NAME
}

function retrieve_target_directory {
    if [ ! -z "$GITEA_DOWNLOAD_TARGET_DIRECTORY" ]; then
        return
    fi

    echo -n "Target directory: "
    read GITEA_DOWNLOAD_TARGET_DIRECTORY
}

function json_set {
    local data=$1
    local key=$2
    local value=$3
    local use_raw_file=$4

    if [ "$use_raw_file" != "true" ]; then
        echo $data | jq -cr --argjson v "$value" --arg k "$key" '.[$k] = $v'
    else
        local tmpfile=$(mktemp)
        echo "$value" > "$tmpfile"
        echo $data | jq -cr --rawfile v "$tmpfile" --arg k "$key" '.[$k] = $v'
        rm -f "$tmpfile"
    fi
}

function gitea_api {
    local path=$1
    local args=${@:2}

    curl -L \
        --fail \
        --ipv4 \
        -u "$GITEA_DOWNLOAD_USERNAME:$GITEA_DOWNLOAD_PASSWORD" \
        ${args} \
        "$GITEA_DOWNLOAD_BASE_URL/api/v1$path"
}

function gitea_download {
    local attachment_id=$1
    local output=$2

    curl -L \
        --fail \
        --ipv4 \
        -u "$GITEA_DOWNLOAD_USERNAME:$GITEA_DOWNLOAD_PASSWORD" \
        --output "$output" \
        "$GITEA_DOWNLOAD_BASE_URL/attachments/$attachment_id"
}

function download_release_files {
    local releases=$(gitea_api "/repos/${GITEA_DOWNLOAD_ORG}/${GITEA_DOWNLOAD_PROJECT}/releases")

    local assets
    if [ "$GITEA_DOWNLOAD_RELEASE_NAME" == "latest" ]; then
        assets=$(echo $releases | jq -r '. | sort_by(.id) | reverse | .[0].assets')
    else
        assets=$(echo $releases | jq -r --arg name "$GITEA_DOWNLOAD_RELEASE_NAME" '. | map(select( .name == $name)) | .[0].assets')
    fi

    if [ "$assets" == "null" ]; then
        echo 1>&2 "No release found."
        exit 1
    fi

    mkdir -p "$GITEA_DOWNLOAD_TARGET_DIRECTORY"

    local attachment_uuids=$(echo $assets | jq -r '.[].uuid')

    for uuid in $attachment_uuids; do
        local filename=$(echo $assets | jq -r --arg uuid "$uuid" '. | map(select( .uuid == $uuid)) | .[0].name')        
        gitea_download "$uuid" "$GITEA_DOWNLOAD_TARGET_DIRECTORY/$filename"
    done
}

function main {
    check_dependencies
    source_env_file
    check_environment
    ask_credentials
    retrieve_release_name
    retrieve_target_directory
    download_release_files
}

main