apt-proxy

#!/usr/bin/env bash
set -euo pipefail

PROXY="http://10.17.89.69:3142/"
WARM_SOURCES_DIR="$(mktemp -d /tmp/acng-warm-sources.XXXXXX)"

cleanup() {
    rm -rf "$WARM_SOURCES_DIR"
}
trap cleanup EXIT

rewrite_url() {
    local url="$1"
    local suffix=""

    case "$url" in
        https://downloads.cursor.com/aptrepo|https://downloads.cursor.com/aptrepo/*)
            suffix="${url#https://downloads.cursor.com/aptrepo}"
            suffix="${suffix#/}"
            if [ -n "$suffix" ]; then
                printf 'http://cursor.cache/%s\n' "$suffix"
            else
                printf 'http://cursor.cache\n'
            fi
            ;;
        https://dl.google.com/linux/chrome/deb|https://dl.google.com/linux/chrome/deb/*)
            suffix="${url#https://dl.google.com/linux/chrome/deb}"
            suffix="${suffix#/}"
            if [ -n "$suffix" ]; then
                printf 'http://chrome.cache/%s\n' "$suffix"
            else
                printf 'http://chrome.cache\n'
            fi
            ;;
        https://deb.nodesource.com/node_23.x|https://deb.nodesource.com/node_23.x/*)
            suffix="${url#https://deb.nodesource.com/node_23.x}"
            suffix="${suffix#/}"
            if [ -n "$suffix" ]; then
                printf 'http://nodesrc.cache/%s\n' "$suffix"
            else
                printf 'http://nodesrc.cache\n'
            fi
            ;;
        https://deb.packages.mattermost.com|https://deb.packages.mattermost.com/*)
            suffix="${url#https://deb.packages.mattermost.com}"
            suffix="${suffix#/}"
            if [ -n "$suffix" ]; then
                printf 'http://matter.cache/%s\n' "$suffix"
            else
                printf 'http://matter.cache\n'
            fi
            ;;
        https://packages.microsoft.com/repos/code|https://packages.microsoft.com/repos/code/*)
            suffix="${url#https://packages.microsoft.com/repos/code}"
            suffix="${suffix#/}"
            if [ -n "$suffix" ]; then
                printf 'http://mscode.cache/%s\n' "$suffix"
            else
                printf 'http://mscode.cache\n'
            fi
            ;;
        https://ppa.launchpad.net/*)
            suffix="${url#https://ppa.launchpad.net/}"
            printf 'http://lp.cache/%s\n' "$suffix"
            ;;
        https://ppa.launchpadcontent.net/*)
            suffix="${url#https://ppa.launchpadcontent.net/}"
            printf 'http://lp.cache/%s\n' "$suffix"
            ;;
        *)
            # For http://apt.pop-os.org/... or anything else:
            printf '%s\n' "$url"
            ;;
    esac
}

process_deb822_file() {
    local file="$1"
    local output_file="$2"
    local types=""
    local uris=""
    local suites=""
    local components=""
    local architectures=""
    local signed_by=""
    local enabled=""
    local in_stanza=false
    local stanza_lines=()

    while IFS= read -r line || [ -n "$line" ]; do
        # Blank line indicates end of stanza
        if [[ -z "$line" || "$line" =~ ^[[:space:]]*$ ]]; then
            if [ "$in_stanza" = true ]; then
                # Output the stanza with rewritten URIs
                for stanza_line in "${stanza_lines[@]}"; do
                    if [[ "$stanza_line" =~ ^([[:space:]]*URIs:[[:space:]]*)(.*)$ ]]; then
                        local prefix="${BASH_REMATCH[1]}"
                        local uris_list="${BASH_REMATCH[2]}"
                        local rewritten_uris=""
                        local first=true

                        for uri in $uris_list; do
                            local new_uri
                            new_uri=$(rewrite_url "$uri")
                            
                            if [ "$first" = true ]; then
                                rewritten_uris="$new_uri"
                                first=false
                            else
                                rewritten_uris="$rewritten_uris $new_uri"
                            fi
                        done
                        echo "${prefix}${rewritten_uris}" >> "$output_file"
                    else
                        echo "$stanza_line" >> "$output_file"
                    fi
                done
                echo "" >> "$output_file"
            fi
            # Reset for next stanza
            types=""
            uris=""
            suites=""
            components=""
            architectures=""
            signed_by=""
            enabled=""
            in_stanza=false
            stanza_lines=()
            continue
        fi

        # Collect all lines in the stanza
        if [[ "$line" =~ ^[[:space:]]*# ]]; then
            stanza_lines+=("$line")
        elif [[ "$line" =~ ^[[:space:]]*(Types|URIs|Suites|Components|Architectures|Signed-By|Enabled): ]]; then
            in_stanza=true
            stanza_lines+=("$line")
        else
            stanza_lines+=("$line")
        fi
    done < "$file"

    # Handle last stanza if file doesn't end with blank line
    if [ "$in_stanza" = true ] && [ ${#stanza_lines[@]} -gt 0 ]; then
        for stanza_line in "${stanza_lines[@]}"; do
            if [[ "$stanza_line" =~ ^([[:space:]]*URIs:[[:space:]]*)(.*)$ ]]; then
                local prefix="${BASH_REMATCH[1]}"
                local uris_list="${BASH_REMATCH[2]}"
                local rewritten_uris=""
                local first=true

                for uri in $uris_list; do
                    local new_uri
                    new_uri=$(rewrite_url "$uri")
                    
                    if [ "$first" = true ]; then
                        rewritten_uris="$new_uri"
                        first=false
                    else
                        rewritten_uris="$rewritten_uris $new_uri"
                    fi
                done
                echo "${prefix}${rewritten_uris}" >> "$output_file"
            else
                echo "$stanza_line" >> "$output_file"
            fi
        done
    fi
}

convert_old_format_to_deb822() {
    local file="$1"
    local output_file="$2"

    while IFS= read -r line || [ -n "$line" ]; do
        case "$line" in
            deb\ *|deb-src\ *)
                local type="deb"
                local opts=""
                local url=""
                local suite=""
                local components=""
                local arch=""
                local signed_by=""

                # Use regex to parse: deb[-src] [options] URL suite components...
                if [[ "$line" =~ ^(deb-src|deb)[[:space:]]+(.*)$ ]]; then
                    type="${BASH_REMATCH[1]}"
                    local rest="${BASH_REMATCH[2]}"
                    
                    # Extract options bracket if present
                    if [[ "$rest" =~ ^\[([^\]]+)\][[:space:]]+(.*)$ ]]; then
                        opts="${BASH_REMATCH[1]}"
                        rest="${BASH_REMATCH[2]}"
                    fi
                    
                    # Parse URL, suite, and components from remaining line
                    # Split by whitespace - first is URL, second is suite, rest are components
                    set -- $rest
                    url="$1"
                    if [ $# -ge 2 ]; then
                        suite="$2"
                        shift 2
                        components="$*"
                    fi
                fi

                # Parse options for arch and signed-by
                if [ -n "$opts" ]; then
                    if [[ "$opts" =~ arch=([^[:space:],]+) ]]; then
                        arch="${BASH_REMATCH[1]}"
                    fi
                    if [[ "$opts" =~ signed-by=([^[:space:],]+) ]]; then
                        signed_by="${BASH_REMATCH[1]}"
                    fi
                fi

                # Skip if URL is empty
                [ -z "$url" ] && continue

                # Rewrite URL
                local new_url
                new_url=$(rewrite_url "$url")

                # Output in deb822 format
                echo "Types: $type" >> "$output_file"
                echo "URIs: $new_url" >> "$output_file"
                if [ -n "$suite" ]; then
                    echo "Suites: $suite" >> "$output_file"
                fi
                if [ -n "$components" ]; then
                    echo "Components: $components" >> "$output_file"
                fi
                if [ -n "$arch" ]; then
                    echo "Architectures: $(echo $arch | tr ',' ' ')" >> "$output_file"
                fi
                if [ -n "$signed_by" ]; then
                    echo "Signed-By: $signed_by" >> "$output_file"
                fi
                echo "" >> "$output_file"
                ;;
            *)
                # Skip comments and blank lines for now
                ;;
        esac
    done < "$file"
}

generate_warm_sources() {
    local counter=0

    # Process old-format .list files and convert to deb822
    for file in /etc/apt/sources.list /etc/apt/sources.list.d/*.list; do
        [ -f "$file" ] || continue
        counter=$((counter + 1))
        convert_old_format_to_deb822 "$file" "${WARM_SOURCES_DIR}/source${counter}.sources"
    done

    # Process new deb822-format .sources files
    for file in /etc/apt/sources.list.d/*.sources; do
        [ -f "$file" ] || continue
        counter=$((counter + 1))
        local filename=$(basename "$file")
        process_deb822_file "$file" "${WARM_SOURCES_DIR}/${filename}"
    done
}

# Ensure curl exists (for the proxy-availability check)
if ! command -v curl >/dev/null 2>&1; then
    sudo apt-get install -y curl
fi

# Only bother with warm-sources if proxy is reachable
if curl -s --connect-timeout 1 "$PROXY" >/dev/null 2>&1; then
    generate_warm_sources

    sudo /usr/bin/apt \
        -o Acquire::http::Proxy="$PROXY" \
        -o Acquire::https::Proxy="$PROXY" \
        -o Acquire::By-Hash=true \
        -o Dir::Etc::sourcelist="/dev/null" \
        -o Dir::Etc::sourceparts="$WARM_SOURCES_DIR" \
        "$@"
else
    # fall back to normal behavior if proxy is down
    sudo /usr/bin/apt "$@"
fi