#!/usr/bin/env bash
export LC_ALL=C
set -e -o pipefail

# Source the common prelude, which:
#   1. Checks if we're at the top directory of the Feather Wallet repository
#   2. Defines a few common functions and variables
#
# shellcheck source=libexec/prelude.bash
source "$(dirname "${BASH_SOURCE[0]}")/libexec/prelude.bash"


###################
## SANITY CHECKS ##
###################

################
# Required non-builtin commands should be invocable
################

check_tools cat mkdir git guix

################
# Required env vars should be non-empty
################

cmd_usage() {
    cat <<EOF
Synopsis:

    env GUIX_SIGS_REPO=<path/to/feather-sigs> \\
      ./contrib/guix/guix-codesign

EOF
}

if [ -z "$GUIX_SIGS_REPO" ]; then
    cmd_usage
    exit 1
fi

################
# GUIX_BUILD_OPTIONS should be empty
################
#
# GUIX_BUILD_OPTIONS is an environment variable recognized by guix commands that
# can perform builds. This seems like what we want instead of
# ADDITIONAL_GUIX_COMMON_FLAGS, but the value of GUIX_BUILD_OPTIONS is actually
# _appended_ to normal command-line options. Meaning that they will take
# precedence over the command-specific ADDITIONAL_GUIX_<CMD>_FLAGS.
#
# This seems like a poor user experience. Thus we check for GUIX_BUILD_OPTIONS's
# existence here and direct users of this script to use our (more flexible)
# custom environment variables.
if [ -n "$GUIX_BUILD_OPTIONS" ]; then
cat << EOF
Error: Environment variable GUIX_BUILD_OPTIONS is not empty:
  '$GUIX_BUILD_OPTIONS'

Unfortunately this script is incompatible with GUIX_BUILD_OPTIONS, please unset
GUIX_BUILD_OPTIONS and use ADDITIONAL_GUIX_COMMON_FLAGS to set build options
across guix commands or ADDITIONAL_GUIX_<CMD>_FLAGS to set build options for a
specific guix command.

See contrib/guix/README.md for more details.
EOF
exit 1
fi

################
# The codesignature git worktree should not be dirty
################

if ! git -C "$GUIX_SIGS_REPO" diff-index --quiet HEAD -- && [ -z "$FORCE_DIRTY_WORKTREE" ]; then
    cat << EOF
ERR: The DETACHED CODESIGNATURE git worktree is dirty, which may lead to broken builds.

     Aborting...

Hint: To make your git worktree clean, You may want to:
      1. Commit your changes,
      2. Stash your changes, or
      3. Set the 'FORCE_DIRTY_WORKTREE' environment variable if you insist on
         using a dirty worktree
EOF
    exit 1
fi

################
# Build directories should not exist
################

# Default to building for all supported HOSTs (overridable by environment)
export HOSTS="${HOSTS:-x86_64-w64-mingw32 x86_64-w64-mingw32.installer}"

# Usage: distsrc_for_host HOST
#
#   HOST: The current platform triple we're building for
#
distsrc_for_host() {
    echo "${DISTSRC_BASE}/build/distsrc-${VERSION}-${1}-codesigned"
}

# Accumulate a list of build directories that already exist...
hosts_distsrc_exists=""
for host in $HOSTS; do
    if [ -e "$(distsrc_for_host "$host")" ]; then
        hosts_distsrc_exists+=" ${host}"
    fi
done

if [ -n "$hosts_distsrc_exists" ]; then
# ...so that we can print them out nicely in an error message
cat << EOF
ERR: Build directories for this commit already exist for the following platform
     triples you're attempting to build, probably because of previous builds.
     Please remove, or otherwise deal with them prior to starting another build.

     Aborting...

Hint: To blow everything away, you may want to use:

  $ ./contrib/guix/guix-clean

Specifically, this will remove all files without an entry in the index,
excluding the SDK directory, the depends download cache, the depends built
packages cache, the garbage collector roots for Guix environments, and the
output directory.
EOF
for host in $hosts_distsrc_exists; do
    echo "     ${host} '$(distsrc_for_host "$host")'"
done
exit 1
else
    mkdir -p "$DISTSRC_BASE"
fi


################
# Unsigned files SHOULD exist
################

# Usage: outdir_for_host HOST SUFFIX
#
#   HOST: The current platform triple we're building for
#
outdir_for_host() {
    echo "${OUTDIR_BASE}/${1}${2:+-${2}}"
}

# Usage: logdir_for_host HOST SUFFIX
#
#   HOST: The current platform triple we're building for
#
logdir_for_host() {
    echo "${LOGDIR_BASE}/${1}${2:+-${2}}"
}

unsigned_file_for_host() {
    case "$1" in
        *mingw32.installer)
            echo "$(outdir_for_host "$1")/FeatherWalletSetup-${VERSION}-unsigned.exe"
            ;;
        *mingw32*)
            echo "$(outdir_for_host "$1")/${DISTNAME}-unsigned.exe"
            ;;
        *)
            exit 1
            ;;
    esac
}

# Accumulate a list of build directories that already exist...
hosts_file_tarball_missing=""
for host in $HOSTS; do
    if [ ! -e "$(unsigned_file_for_host "$host")" ]; then
        hosts_file_tarball_missing+=" ${host}"
    fi
done

if [ -n "$hosts_file_tarball_missing" ]; then
    # ...so that we can print them out nicely in an error message
    cat << EOF
ERR: Unsigned files do not exist
...

EOF
for host in $hosts_file_tarball_missing; do
    echo "     ${host} '$(unsigned_file_for_host "$host")'"
done
exit 1
fi

################
# Check that we can connect to the guix-daemon
################

cat << EOF
Checking that we can connect to the guix-daemon...

Hint: If this hangs, you may want to try turning your guix-daemon off and on
      again.

EOF
if ! guix gc --list-failures > /dev/null; then
    cat << EOF

ERR: Failed to connect to the guix-daemon, please ensure that one is running and
     reachable.
EOF
    exit 1
fi

# Developer note: we could use `guix repl` for this check and run:
#
#     (import (guix store)) (close-connection (open-connection))
#
# However, the internal API is likely to change more than the CLI invocation


#########
# SETUP #
#########

# Determine the maximum number of jobs to run simultaneously (overridable by
# environment)
JOBS="${JOBS:-$(nproc)}"

# Determine the reference time used for determinism (overridable by environment)
SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:-$(git -c log.showSignature=false log --format=%at -1)}"

# Make sure an output directory exists for our builds
OUTDIR_BASE="${OUTDIR_BASE:-${VERSION_BASE}/output}"
mkdir -p "$OUTDIR_BASE"

# Usage: profiledir_for_host HOST SUFFIX
#
#   HOST: The current platform triple we're building for
#
profiledir_for_host() {
    echo "${PROFILES_BASE}/${1}${2:+-${2}}"
}

#########
# BUILD #
#########

# Function to be called when codesigning for host ${1} and the user interrupts
# the codesign
int_trap() {
cat << EOF
** INT received while codesigning ${1}, you may want to clean up the relevant
   work directories (e.g. distsrc-*) before recodesigning

Hint: To blow everything away, you may want to use:

  $ ./contrib/guix/guix-clean

Specifically, this will remove all files without an entry in the index,
excluding the SDK directory, the depends download cache, the depends built
packages cache, the garbage collector roots for Guix environments, and the
output directory.
EOF
}

# shellcheck disable=SC2153
for host in $HOSTS; do

    # Display proper warning when the user interrupts the build
    trap 'int_trap ${host}' INT

    (
        # Required for 'contrib/guix/manifest.scm' to output the right manifest
        # for the particular $HOST we're building for
        export HOST="$host"

        # shellcheck disable=SC2030
cat << EOF
INFO: Codesigning ${VERSION:?not set} for platform triple ${HOST:?not set}:
      ...using reference timestamp: ${SOURCE_DATE_EPOCH:?not set}
      ...from worktree directory: '${PWD}'
          ...bind-mounted in container to: '/feather'
      ...in build directory: '$(distsrc_for_host "$HOST")'
          ...bind-mounted in container to: '$(DISTSRC_BASE=/distsrc-base && distsrc_for_host "$HOST")'
      ...outputting in: '$(outdir_for_host "$HOST" codesigned)'
          ...bind-mounted in container to: '$(OUTDIR_BASE=/outdir-base && outdir_for_host "$HOST" codesigned)'
      ...using detached signatures in: '${GUIX_SIGS_REPO:?not set}'
          ...bind-mounted in container to: '/detached-sigs'
EOF

        # shellcheck disable=SC2086,SC2031
        time-machine shell --manifest="${PWD}/contrib/guix/manifest.scm" \
                                 --container \
                                 --pure \
                                 --no-cwd \
                                 --share="$PWD"=/feather \
                                 --share="$DISTSRC_BASE"=/distsrc-base \
                                 --share="$OUTDIR_BASE"=/outdir-base \
                                 --share="$LOGDIR_BASE"=/logdir-base \
                                 --share="$GUIX_SIGS_REPO"=/guix-sigs \
                                 --expose="$(git rev-parse --git-common-dir)" \
                                 --expose="$(git -C "$GUIX_SIGS_REPO" rev-parse --git-common-dir)" \
                                 ${SOURCES_PATH:+--share="$SOURCES_PATH"} \
                                 --cores="$JOBS" \
                                 --keep-failed \
                                 --fallback \
                                 --link-profile \
                                 --user="user" \
                                 --root="$(profiledir_for_host "${HOST}" codesigned)" \
                                 ${SUBSTITUTE_URLS:+--substitute-urls="$SUBSTITUTE_URLS"} \
                                 ${ADDITIONAL_GUIX_COMMON_FLAGS} ${ADDITIONAL_GUIX_ENVIRONMENT_FLAGS} \
                                 -- env HOST="$host" \
                                        DISTNAME="$DISTNAME" \
                                        VERSION="$VERSION" \
                                        JOBS="$JOBS" \
                                        SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:?unable to determine value}" \
                                        ${V:+V=1} \
                                        ${SOURCES_PATH:+SOURCES_PATH="$SOURCES_PATH"} \
                                        DISTSRC="$(DISTSRC_BASE=/distsrc-base && distsrc_for_host "$HOST")" \
                                        OUTDIR="$(OUTDIR_BASE=/outdir-base && outdir_for_host "$HOST" codesigned)" \
                                        LOGDIR="$(LOGDIR_BASE=/logdir-base && logdir_for_host "$HOST" codesigned)" \
                                        GUIX_SIGS_REPO=/guix-sigs \
                                        UNSIGNED_FILE="$(OUTDIR_BASE=/outdir-base && unsigned_file_for_host "$HOST")" \
                                      bash -c "cd /feather && bash contrib/guix/libexec/codesign.sh"
    )

done