#!/usr/bin/env bash

set -u

# Following variables should be set in environment outside of this script.
# Build updated packages.
: "${BUILD_PACKAGES:=false}"
# Commit changes to Git.
: "${GIT_COMMIT_PACKAGES:=false}"
# Push changes to remote.
: "${GIT_PUSH_PACKAGES:=false}"

export TERMUX_PKG_UPDATE_METHOD=""             # Which method to use for updating? (repology, github or gitlab)
export TERMUX_PKG_UPDATE_TAG_TYPE=""           # Whether to use latest-release-tag or newest-tag.
export TERMUX_GITLAB_API_HOST="gitlab.com"     # Default host for gitlab-ci.
export TERMUX_PKG_AUTO_UPDATE=false            # Whether to auto-update or not. Disabled by default.
export TERMUX_PKG_UPDATE_VERSION_REGEXP=""     # Regexp to extract version with `grep -oP`.
export TERMUX_PKG_UPDATE_VERSION_SED_REGEXP="" # Regexp to extract version with `sed`.
export TERMUX_REPOLOGY_DATA_FILE
TERMUX_REPOLOGY_DATA_FILE="$(mktemp -t termux-repology.XXXXXX)" # File to store repology data.

export TERMUX_SCRIPTDIR
TERMUX_SCRIPTDIR=$(realpath "$(dirname "$0")/../..") # Root of repository.

export TERMUX_PACKAGES_DIRECTORIES
TERMUX_PACKAGES_DIRECTORIES=$(jq --raw-output 'del(.pkg_format) | keys | .[]' "${TERMUX_SCRIPTDIR}"/repo.json)

# Define few more variables used by scripts.
# shellcheck source=scripts/properties.sh
. "${TERMUX_SCRIPTDIR}/scripts/properties.sh"

# Utility function to write error message to stderr.
# shellcheck source=scripts/updates/utils/termux_error_exit.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/utils/termux_error_exit.sh

# Utility function to write updated version to build.sh.
# shellcheck source=scripts/updates/utils/termux_pkg_upgrade_version.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/utils/termux_pkg_upgrade_version.sh

# Utility function to check if package needs to be updated, based on version comparison.
# shellcheck source=scripts/updates/utils/termux_pkg_is_update_needed.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/utils/termux_pkg_is_update_needed.sh

# Wrapper around github api to get latest release or newest tag.
# shellcheck source=scripts/updates/api/termux_github_api_get_tag.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/api/termux_github_api_get_tag.sh

# Wrapper around gitlab api to get latest release or newest tag.
# shellcheck source=scripts/updates/api/termux_gitlab_api_get_tag.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/api/termux_gitlab_api_get_tag.sh

# Function to get latest version of a package as per repology.
# shellcheck source=scripts/updates/api/termux_repology_api_get_latest_version.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/api/termux_repology_api_get_latest_version.sh

# Default auto update script for packages hosted on github.com. Should not be overrided by build.sh.
# To use custom algorithm, one should override termux_pkg_auto_update().
# shellcheck source=scripts/updates/internal/termux_github_auto_update.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/internal/termux_github_auto_update.sh

# Default auto update script for packages hosted on hosts using gitlab-ci. Should not be overrided by build.sh.
# To use custom algorithm, one should override termux_pkg_auto_update().
# shellcheck source=scripts/updates/internal/termux_gitlab_auto_update.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/internal/termux_gitlab_auto_update.sh

# Default auto update script for rest packages. Should not be overrided by build.sh.
# To use custom algorithm, one should override termux_pkg_auto_update().
# shellcheck source=scripts/updates/internal/termux_repology_auto_update.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/internal/termux_repology_auto_update.sh

# Main script to:
# - by default, decide which update method to use,
# - but can be overrided by build.sh to use custom update method.
# - For example: see neovim-nightly's build.sh.
# shellcheck source=scripts/updates/termux_pkg_auto_update.sh
. "${TERMUX_SCRIPTDIR}"/scripts/updates/termux_pkg_auto_update.sh

# Converts milliseconds to human-readable format. 
# Example: `ms_to_human_readable 123456789` => 34h 17m 36s 789ms
ms_to_human_readable() {
	echo "$(($1/3600000))h $(($1%3600000/60000))m $(($1%60000/1000))s $(($1%1000))ms" | sed 's/0h //;s/0m //;s/0s //'
}

# Runs a command without displaying its output in the case if trace is disabled and displays output in the case if it is enabled.
# Needed only for debugging
quiet() {
	if [[ "$-" =~ x ]]; then
		"$@"
	else
		&>/dev/null "$@"
	fi
	return $?
}

_update() {
	export TERMUX_PKG_NAME
	TERMUX_PKG_NAME="$(basename "$1")"
	export TERMUX_PKG_BUILDER_DIR
	TERMUX_PKG_BUILDER_DIR="$(realpath "$1")" # Directory containing build.sh.

	IFS="," read -r -a BLACKLISTED_ARCH <<<"${TERMUX_PKG_BLACKLISTED_ARCHES:-}"
	export TERMUX_ARCH="" # Arch to test updates.
	for arch in aarch64 arm i686 x86_64; do
		# shellcheck disable=SC2076
		if [[ ! " ${BLACKLISTED_ARCH[*]} " =~ " ${arch} " ]]; then
			TERMUX_ARCH="${arch}"
			break
		fi
	done
	# Set +e +u to avoid:
	# - ending on errors such as $(which prog), where prog is not installed.
	# - error on unbound variable. (All global variables used should be covered by properties.sh and above.)
	set +e +u
	# shellcheck source=/dev/null
	. "${TERMUX_PKG_BUILDER_DIR}"/build.sh 2>/dev/null
	set -e -u

	echo # Newline.
	echo "INFO: Updating ${TERMUX_PKG_NAME} [Current version: ${TERMUX_PKG_VERSION}]"
	termux_pkg_auto_update
}

declare -A _LATEST_TAGS=()
declare -A _FAILED_UPDATES=()
declare -a _ALREADY_SEEN=() # Array of packages successfully updated or skipped.

# _fetch_and_cache_tags fetches all possible tags using termux_pkg_auto_update, but using Ninja build system. 
# The key difference is that we make the process concurrent, allowing us to fetch tags simultaneously rather than one at a time. 
# Once all tags are cached, the termux_pkg_auto_update function will operate much more quickly. 
# We avoid packages with overwritten termux_pkg_auto_update to prevent unexpected modifications to the package`s build.sh.
_fetch_and_cache_tags() {
	if [ "$(uname -o)" = "Android" ] || [ -e "/system/bin/app_process" ]; then
		if ! command -v ninja &> /dev/null; then
			echo "INFO: Skipping fetching and caching tags. Package 'ninja' is not installed."
			return 0
		fi
	fi
	
	if ! command -v ninja &> /dev/null; then
		echo "INFO: Fetching ninja build system"
		. "${TERMUX_SCRIPTDIR}"/scripts/build/termux_download.sh
		. "${TERMUX_SCRIPTDIR}"/scripts/build/setup/termux_setup_ninja.sh
		TERMUX_ON_DEVICE_BUILD=false TERMUX_COMMON_CACHEDIR=/tmp TERMUX_PKG_TMPDIR=/tmp termux_setup_ninja
	fi

	echo "INFO: Fetching and caching tags"

	# First invocation of termux_repology_api_get_latest_version fetches and caches repology metadata.
	quiet termux_repology_api_get_latest_version ' '

    local __PACKAGES=()
	for repo_dir in $(jq --raw-output 'del(.pkg_format) | keys | .[]' "${TERMUX_SCRIPTDIR}/repo.json"); do
		for pkg_dir in "${repo_dir}"/*; do
			! quiet _should_update "${pkg_dir}" && continue # Skip if not needed.
			grep -q '^termux_pkg_auto_update' "${pkg_dir}/build.sh" && continue # Skip if package has custom auto-update
			__PACKAGES+=("${pkg_dir}")
		done
	done

	__main__() {
		cd ${TERMUX_SCRIPTDIR}
		export TERMUX_PKG_NAME="${1##*/}" TERMUX_PKG_BUILDER_DIR=${1}
		set +eu;
		for i in scripts/updates/{**/,}*.sh "${1}/build.sh"; do source ${i}; done
		set -eu
		termux_pkg_upgrade_version() {
			[[ -n "$1" ]] && echo "PKG|$TERMUX_PKG_NAME|${1#*:}"
			exit 0
		}
		termux_repology_auto_update() {
			echo "PKG|$TERMUX_PKG_NAME|$(termux_repology_api_get_latest_version "${TERMUX_PKG_NAME}" | sed "s/^null$/${TERMUX_PKG_VERSION#*:}/")"
			exit 0
		}
		termux_pkg_auto_update
	}

	__generate__() {
		echo "rule update"
		echo " command = bash -c \"\$\$F\" -- \$pkg_dir ||:"
		sed 's/[^ ]\+/\nbuild &: update\n pkg_dir=&/g' <<< "${__PACKAGES[@]}"
		echo "build run_all: phony ${__PACKAGES[@]}"
		echo "default run_all"
	}
	
	local LATEST_TAGS="$(\
		F="$(declare -p TERMUX_SCRIPTDIR GITHUB_TOKEN TERMUX_REPOLOGY_DATA_FILE); $(declare -f __main__ | sed 's/__main__ ()//')" \
		env --chdir=/tmp  ninja -f /dev/stdin <<< "$(__generate__)" |& grep "^PKG|"
	)"
	
	unset -f __main__  __generate__
	while IFS='|' read -r _ pkg version; do
		_LATEST_TAGS["${pkg:-_}"]="$version"
	done <<< "$LATEST_TAGS"
	quiet declare -p _LATEST_TAGS
}

_check_updated() {
	if [[ -n "${_LATEST_TAGS[${1##*/}]:-}" ]]; then
		(
			set +eu
			quiet source "${1}/build.sh"
			set -eu
			export TERMUX_PKG_UPGRADE_VERSION_DRY_RUN=1
			if quiet termux_pkg_upgrade_version "${_LATEST_TAGS[${1##*/}]}"; then
				echo "INFO: Skipping ${1##*/}: already at version ${TERMUX_PKG_VERSION#*:}"
				return 0
			fi
			return 1
		)
		local _ANSWER=$?
		if (( _ANSWER == 0 )) ; then
			_ALREADY_SEEN+=("$(basename "${1}")")
		fi
		return $_ANSWER
	fi
	return 1
}

_run_update() {
	local pkg_dir="$1"
	[[ -n "${_LATEST_TAGS[${pkg_dir##*/}]:-}" ]] && export __CACHED_TAG="${_LATEST_TAGS[${pkg_dir##*/}]}"
	# Run each package update in separate process since we include their environment variables.
	local output=""
	{
		output=$(
			set -euo pipefail
			_update "${pkg_dir}" 2>&1 | tee /dev/fd/3 # fd 3 is used to output to stdout as well.
			exit "${PIPESTATUS[0]}"                   # Return exit code of _update.
		)
	} 3>&1
	# shellcheck disable=SC2181
	if [[ $? -ne 0 ]]; then
		_FAILED_UPDATES["$(basename "${pkg_dir}")"]="${output}"
	else
		_ALREADY_SEEN+=("$(basename "${pkg_dir}")")
	fi
	unset __CACHED_TAG
}

declare -a _CACHED_ISSUE_TITLES=()
# Check if an issue with same title already exists and is open.
_gh_check_issue_exists() {
	local pkg_name="$1"
	if [[ -z "${_CACHED_ISSUE_TITLES[*]}" ]]; then
		while read -r title; do
			_CACHED_ISSUE_TITLES+=("'${title}'") # An extra quote ('') is added to avoid false positive matches.
		done <<<"$(
			gh issue list \
				--label "auto update failing" --label "bot" \
				--state open \
				--search "Auto update failing for in:title type:issue" \
				--json title | jq -r '.[] | .title'
		)"
	fi
	# shellcheck disable=SC2076 # We want literal match here, not regex based.
	if [[ "${_CACHED_ISSUE_TITLES[*]}" =~ "'Auto update failing for ${pkg_name}'" ]]; then
		return 0
	fi
	return 1
}

_should_update() {
	local pkg_dir="$1"

	if [[ ! -f "${pkg_dir}/build.sh" ]]; then
		# Fail if detected a non-package directory.
		termux_error_exit "ERROR: directory '${pkg_dir}' is not a package."
	fi

	if { [[ "${PACKAGES_OPT_OUT:-}" == "true" ]] && grep -q '^TERMUX_PKG_AUTO_UPDATE=false$' "${pkg_dir}/build.sh"; } || \
			{ [[ "${PACKAGES_OPT_OUT:-}" != "true" ]] && ! grep -q '^TERMUX_PKG_AUTO_UPDATE=true$' "${pkg_dir}/build.sh"; }; then
		return 1 # Skip.
	fi

	# shellcheck disable=SC2076
	if [[ " ${_ALREADY_SEEN[*]} ${!_FAILED_UPDATES[*]} " =~ " $(basename "${pkg_dir}") " ]]; then
		return 1 # Skip.
	fi
	if [[ "${GITHUB_ACTIONS:-}" == "true" ]] && _gh_check_issue_exists "$(basename "${pkg_dir}")"; then
		echo "INFO: Skipping '$(basename "${pkg_dir}")', an update issue for it hasn't been resolved yet."
		return 1
	fi

	return 0
}

shopt -s extglob
_update_dependencies() {
	local pkg_dir="$1"

	if ! grep -qE "^(TERMUX_PKG_DEPENDS|TERMUX_PKG_BUILD_DEPENDS|TERMUX_SUBPKG_DEPENDS)=" \
		"${pkg_dir}"/+(build|*.subpackage).sh; then
		return 0
	fi
	# shellcheck disable=SC2086 # Allow splitting of TERMUX_PACKAGES_DIRECTORIES.
	while read -r dep dep_dir; do
		if [[ -z $dep ]]; then
			continue
		elif [[ "${dep}" == "ERROR" ]]; then
			termux_error_exit "ERROR: Obtaining update order failed for $(basename "${pkg_dir}")"
		fi
		_should_update "${dep_dir}"  && ! _check_updated "${dep_dir}" && _run_update "${dep_dir}"
	done <<<"$("${TERMUX_SCRIPTDIR}"/scripts/buildorder.py "${pkg_dir}" $TERMUX_PACKAGES_DIRECTORIES || echo "ERROR")"
}

echo "INFO: Running update for: $*"

if [[ "$1" == "@all" ]]; then
	_fetch_and_cache_tags
	for repo_dir in $(jq --raw-output 'del(.pkg_format) | keys | .[]' "${TERMUX_SCRIPTDIR}/repo.json"); do
		for pkg_dir in "${repo_dir}"/*; do
			_unix_millis=$(date +%s%N | cut -b1-13)
			! _should_update "${pkg_dir}" && continue # Skip if not needed.
			_check_updated "${pkg_dir}" && continue # Skip if already up-to-date.
			# Update all its dependencies first.
			_update_dependencies "${pkg_dir}"
			# NOTE: I am not cheacking whether dependencies were updated successfully or not.
			# There is no way I could know whether this package will build with current
			# available verions of its dependencies or needs new ones.
			# So, whatever the case may be. We just need packages to be updated in order
			# and not care about anything else in between. If something fails to update,
			# it will be reported by failure handling code, so no worries.
			_run_update "${pkg_dir}"
			echo "termux - took $(ms_to_human_readable $(( $(date +%s%N | cut -b1-13) - _unix_millis )))"
		done
	done
else
	for pkg in "$@"; do
		if [ ! -d "${pkg}" ]; then # If only package name is given, try to find it's directory.
			for repo_dir in $(jq --raw-output 'del(.pkg_format) | keys | .[]' "${TERMUX_SCRIPTDIR}/repo.json"); do
				if [ -d "${repo_dir}/${pkg}" ]; then
					pkg="${repo_dir}/${pkg}"
					break
				fi
			done
		fi
		# Here `pkg` is a directory.
		! _should_update "${pkg}" && continue
		_update_dependencies "${pkg}"
		_run_update "${pkg}"
	done
fi

################################################FAILURE HANDLING#################################################

_gh_create_new_issue() {
	local pkg_name="$1"

	local max_body_length=65536 # Max length of the body for one request.
	local assignee="${GITHUB_ACTOR:-}"
	local issue_number
	local body
	local link

	if [[ "${assignee:-termuxbot2}" == "termuxbot2" ]]; then
		assignee="MrAdityaAlok" # Assign myself if termuxbot2 is the actor.
	fi
	
	# Extract origin URL, commit hash and builder directory and put everything together
	link="$(git config --get remote.origin.url |sed -E 's|\.git$||; s|git@([^:]+):(.+)|https://\1/\2|')/blob/$(git rev-parse HEAD)/$(echo */$1)"

	body="$(
		cat <<-EOF
			Hi, I'm Termux 🤖.

			I'm here to help you update your Termux packages.

			I've tried to update the [${pkg_name}](${link}) package, but it failed.

			Here's the output of the update script:
			<details>
				<summary>Show log</summary>
				<pre lang="bash">${_FAILED_UPDATES["${pkg_name}"]}</pre>
			</details>

			<hr>
			<i>
			Above error occured when I last tried to update at $(date -u +"%Y-%m-%d %H:%M:%S UTC").<br>
			Run ID: <a href="${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}">${GITHUB_RUN_ID}</a><br><br>
			<b>Note:</b> Automatic updates will be disabled until this issue is resolved.<br>
			</i>
		EOF
	)"
	issue_number=$(
		gh issue create \
			--title "Auto update failing for ${pkg_name}" \
			--body "${body:0:${max_body_length}}" \
			--label "auto update failing" --label "bot" \
			--assignee ${assignee} |
			grep -oE "[0-9]+" # Last component of the URL returned is the issue number.
	)
	if [ -z "${issue_number}" ]; then
		echo "ERROR: Failed to create issue."
		return 1
	fi

	echo "INFO: Created issue ${issue_number} for ${pkg_name}."

	if [[ -n "${body:${max_body_length}}" ]]; then
		# The body was too long, so we need to append the rest.
		while true; do
			body="${body:${max_body_length}}"
			if [[ -z "${body}" ]]; then
				break
			fi
			sleep 5 # Otherwise we might get rate limited.
			gh issue edit "$issue_number" \
				--body-file - <<<"$(
					gh issue view "$issue_number" \
						--json body \
						--jq '.body'
				)${body:0:${max_body_length}}" >/dev/null
			# NOTE: we use --body-file instead of --body to avoid shell error 'argument list too long'.
		done
	fi
}

_handle_failure() {
	echo # Newline.
	if [[ "${GITHUB_ACTIONS:-}" == "true" ]]; then
		echo "INFO: Creating issue for failed updates...(if any)"
		for pkg_name in "${!_FAILED_UPDATES[@]}"; do
			_gh_create_new_issue "${pkg_name}"
		done
	else
		echo "==> Failed updates:"
		local count=0
		for pkg_name in "${!_FAILED_UPDATES[@]}"; do
			count=$((count + 1))
			echo "${count}. ${pkg_name}"
		done
		exit 1
	fi
}

if [[ ${#_FAILED_UPDATES[@]} -gt 0 ]]; then
	_handle_failure
fi