# syntax=docker/dockerfile:1.7
#
# Patch lscr.io/linuxserver/plex with the feature-unlock shared library.
#
#   docker build -f docker/Dockerfile.linuxserver -t plex-crack:lsio .
#   docker run -d --name plex --network=host \
#     -e PUID=$(id -u) -e PGID=$(id -g) \
#     -v /srv/plex/config:/config -v /srv/plex/data:/data \
#     plex-crack:lsio
#
# Two stages (mirrors Dockerfile.plexinc):
#   1. builder   -- zig cross-compile plexmediaserver_crack.so (musl)
#   2. runtime   -- layer onto lscr.io/linuxserver/plex + override the s6 plex
#                  service so PMS is exec'd (as user 'abc' via s6-setuidgid,
#                  preserving LSIO's permission model) with LD_PRELOAD.
#
# Why s6-setuidgid is preserved: LSIO's run file drops to the 'abc' user
# (uid 911) before exec'ing the PMS binary. If we don't keep that, PMS
# would run as root, which (a) breaks LSIO's permission model, (b) prevents
# writes to /config and /data which are chowned to abc on first start,
# (c) makes the container harder to use (root-owned media library).

# ── Build args (global -- visible to every FROM) ──────────────────────────
ARG PLEX_BASE_IMAGE=lscr.io/linuxserver/plex:latest

# ── Stage 1: build the musl .so (identical to plexinc) ────────────────────
FROM debian:bookworm-slim AS builder

ARG ZIG_VERSION=0.13.0
ARG DEBIAN_FRONTEND=noninteractive
RUN apt-get update \
 && apt-get install -y --no-install-recommends \
        ca-certificates curl xz-utils \
 && rm -rf /var/lib/apt/lists/*

WORKDIR /src
RUN mkdir -p /src/toolchain \
 && curl -fsSL \
      "https://ziglang.org/download/${ZIG_VERSION}/zig-linux-x86_64-${ZIG_VERSION}.tar.xz" \
      -o /tmp/zig.tar.xz \
 && tar -C /src/toolchain --strip-components=1 -xf /tmp/zig.tar.xz \
 && rm /tmp/zig.tar.xz
ENV PATH="/src/toolchain:${PATH}"

COPY build.sh ./
COPY src ./src
COPY third_party ./third_party
RUN bash build.sh

# ── Stage 2: runtime -- patch lscr.io/linuxserver/plex ────────────────────
FROM ${PLEX_BASE_IMAGE} AS runtime

ARG PLEX_BASE_IMAGE
ARG PATCH_VERSION=dev
LABEL org.opencontainers.image.title="plexmediaserver-crack (linuxserver)" \
      org.opencontainers.image.source="https://github.com/authrequest/Freeloader" \
      org.opencontainers.image.licenses="AGPL-3.0-or-later" \
      plex_patch.base="${PLEX_BASE_IMAGE}" \
      plex_patch.version="${PATCH_VERSION}"

# Sanity: refuse to build on an unfamiliar upstream layout.
RUN set -eux; \
    PMS="/usr/lib/plexmediaserver/Plex Media Server"; \
    PMS_LIB="/usr/lib/plexmediaserver/lib"; \
    RUN_SCRIPT="/etc/s6-overlay/s6-rc.d/svc-plex/run"; \
    [ -x "${PMS}" ]        || { echo "patcher: missing ${PMS} in ${PLEX_BASE_IMAGE}"; exit 1; }; \
    [ -d "${PMS_LIB}" ]    || { echo "patcher: missing ${PMS_LIB}/ in ${PLEX_BASE_IMAGE}"; exit 1; }; \
    [ -f "${RUN_SCRIPT}" ] || { echo "patcher: missing ${RUN_SCRIPT} in ${PLEX_BASE_IMAGE}"; exit 1; }

COPY --from=builder /src/build/plexmediaserver_crack.so \
                    /usr/lib/plexmediaserver/lib/plexmediaserver_crack.so
COPY --from=builder /src/build/plexmediaserver_traffic_logger.so \
                    /usr/lib/plexmediaserver/lib/plexmediaserver_traffic_logger.so
COPY docker/wrapper.sh /usr/lib/plexmediaserver/plex-crack-wrapper.sh
RUN chmod 0755 /usr/lib/plexmediaserver/plex-crack-wrapper.sh

# Override the s6 plex service run file. We preserve LSIO's s6-setuidgid
# abc so PMS still runs as user 'abc' (uid 911) -- otherwise /config and
# /data would be created as root and break the LSIO permission model.
RUN set -eux; \
    RUN_SCRIPT="/etc/s6-overlay/s6-rc.d/svc-plex/run"; \
    cp "${RUN_SCRIPT}" "${RUN_SCRIPT}.orig"; \
    printf '#!/usr/bin/with-contenv bash\nexec s6-setuidgid abc /usr/lib/plexmediaserver/plex-crack-wrapper.sh\n' \
        > "${RUN_SCRIPT}"; \
    chmod 0755 "${RUN_SCRIPT}"

# ── Patch the PMS binary in-place to disable transcode session limits ──────
# Patches 6 conditional-jump instructions so the limit-checking code always
# takes the normal (no-error) path. See AGENTS.md for full RE notes.
RUN set -eux; \
    PMS="/usr/lib/plexmediaserver/Plex Media Server"; \
    \
    # Read N bytes at a file offset as hex string (no separator). \
    rd() { dd if="${PMS}" bs=1 skip="$1" count="$2" 2>/dev/null | od -A n -t x1 | tr -d ' \n'; }; \
    \
    # sanity: verify expected bytes at each patch site (guards against version drift) \
    echo "=== verifying patch-site bytes ==="; \
    [ "$(rd 18624607 2)" = "7e0c"         ] || { echo "sanity FAIL at 0x11C305F"; exit 1; }; \
    [ "$(rd 18624781 2)" = "7e08"         ] || { echo "sanity FAIL at 0x11C310D"; exit 1; }; \
    [ "$(rd 18624793 2)" = "7e08"         ] || { echo "sanity FAIL at 0x11C3119"; exit 1; }; \
    [ "$(rd 18624674 6)" = "0f8fc2f6ffff" ] || { echo "sanity FAIL at 0x11C30A2"; exit 1; }; \
    [ "$(rd 18624682 6)" = "0f8f1ef7ffff" ] || { echo "sanity FAIL at 0x11C30AA"; exit 1; }; \
    [ "$(rd 18624630 6)" = "0f8f9f000000" ] || { echo "sanity FAIL at 0x11C3076"; exit 1; }; \
    echo "sanity: expected bytes match, applying patches"; \
    \
    # apply patches \
    # jle -> jmp (2-byte: \353=0xEB  \14=0x0C  \10=0x08) \
    printf '\353\014'      | dd of="${PMS}" bs=1 seek=18624607 conv=notrunc 2>/dev/null; \
    printf '\353\010'      | dd of="${PMS}" bs=1 seek=18624781 conv=notrunc 2>/dev/null; \
    printf '\353\010'      | dd of="${PMS}" bs=1 seek=18624793 conv=notrunc 2>/dev/null; \
    # jg -> NOP (6-byte: \220=0x90) \
    printf '\220\220\220\220\220\220' | dd of="${PMS}" bs=1 seek=18624674 conv=notrunc 2>/dev/null; \
    printf '\220\220\220\220\220\220' | dd of="${PMS}" bs=1 seek=18624682 conv=notrunc 2>/dev/null; \
    printf '\220\220\220\220\220\220' | dd of="${PMS}" bs=1 seek=18624630 conv=notrunc 2>/dev/null; \
    \
    echo "binary patch applied: transcode session limits disabled"