#!/bin/bash

# Matrix (Synapse + Element) install hooks.
#
# Synapse takes essentially no configuration from the environment — it reads
# homeserver.yaml and nothing else — so the real install work is done here:
# generate the signing key, write homeserver.yaml from the template with the
# server name and secrets filled in, write Element's config.json, and create the
# first admin account once the homeserver is answering.

matrix_install_pre()
{
    local app_name="$1"
    if ! appInstallCheckRequirements "$app_name" "$CFG_MATRIX_REQUIRES"; then
        matrix=n
        return 1
    fi
}

# The homeserver's public host — the value that becomes server_name.
#
# Built from the port arrays and $domain_full that variables_init_app has
# already put in scope, NOT by reading DOMAINSUBNAME_TAG_1 out of the deployed
# compose: install_post_compose runs before dockerConfigSetupFileWithData, so at
# that point the compose still holds raw placeholders.
#
# port_subdomains[0] is CFG_MATRIX_PORT_1, the Synapse router — deliberately not
# $host_setup, which for this two-host app resolves to Element instead. The
# empty/@/root cases mirror tagsProcessorPortSubdomains so the name computed
# here and the Traefik rule generated later cannot drift apart.
_matrixServerName()
{
    local sub="${port_subdomains[0]}"
    [[ -z "$domain_full" ]] && return 1
    if [[ "$sub" == "@" || "$sub" == "root" ]]; then
        echo "$domain_full"
    elif [[ -n "$sub" ]]; then
        echo "${sub}.${domain_full}"
    else
        echo "matrix.${domain_full}"
    fi
}

matrix_install_post_compose()
{
    local app_name="$1"
    local app_dir="$containers_dir$app_name"
    local data_dir="$app_dir/data"

    ((menu_number++))
    echo ""
    echo "---- $menu_number. Generating the Synapse homeserver configuration"
    echo ""

    local server_name
    server_name=$(_matrixServerName)
    if [[ -z "$server_name" ]]; then
        isError "No domain is configured — cannot determine the Matrix server_name."
        isNotice "Set CFG_DOMAIN_${CFG_MATRIX_DOMAIN:-1} (General → Network), then reinstall."
        return 1
    fi

    # Same value the compose will hand to Postgres. Taken from the config rather
    # than the compose because the compose is not substituted yet at this point;
    # the config is where the secret is generated and remembered, and the
    # #LIBREPORTAL|MATRIX_DB_PASSWORD_1_TAG| line is filled from this very
    # variable a step later, so the two cannot disagree.
    local db_password="$CFG_MATRIX_DB_PASSWORD_1"
    if [[ -z "$db_password" || "$db_password" == RANDOMIZEDPASSWORD* ]]; then
        isError "CFG_MATRIX_DB_PASSWORD_1 was not generated — aborting Synapse configuration."
        return 1
    fi

    local result
    result=$(createFolders "loud" "$docker_install_user" "$data_dir" "$app_dir/element")
    checkSuccess "Creating $app_name data folders"

    # Synapse signs every federated event with this key, and a peer that has
    # seen one key will reject events signed by a different one. So: generate it
    # exactly once, and never regenerate it over an existing install.
    #
    # Upstream's `generate` command is used rather than hand-rolling the key
    # file, because the format encodes a key ID that other servers cache. It
    # also emits a homeserver.yaml and a log config, which we throw away in
    # favour of the templates below.
    if [[ ! -s "$data_dir/signing.key" ]]; then
        local synapse_image
        synapse_image=$(tagsManagerGetTagContent "$app_dir/docker-compose.yml" "MATRIX_VERSION_TAG")
        synapse_image="matrixdotorg/synapse:${synapse_image:-latest}"

        result=$(runFileOp docker run --rm \
            -e SYNAPSE_SERVER_NAME="$server_name" \
            -e SYNAPSE_REPORT_STATS=no \
            -v "$data_dir":/data \
            "$synapse_image" generate 2>&1)
        checkSuccess "Generating the Synapse signing key with $synapse_image"

        # `generate` names the key after the server; homeserver.yaml expects it
        # at a fixed path so the file does not have to be renamed if the app is
        # ever restored under a different name.
        if [[ -f "$data_dir/$server_name.signing.key" ]]; then
            result=$(runFileOp mv "$data_dir/$server_name.signing.key" "$data_dir/signing.key")
            checkSuccess "Storing the signing key at data/signing.key"
        fi
        # Ours replace both of these.
        result=$(runFileOp rm -f "$data_dir/homeserver.yaml" "$data_dir/$server_name.log.config")
        checkSuccess "Discarding the generated config in favour of the LibrePortal template"
    else
        isNotice "An existing signing key was found — keeping it (regenerating would break federation)."
    fi

    if [[ ! -s "$data_dir/signing.key" ]]; then
        isError "No signing key was produced — Synapse will not start. Check that the image could be pulled."
        return 1
    fi

    result=$(copyResource "$app_name" "homeserver.yaml" "data" | runInstallWrite -a "$logs_dir/$docker_log_file" 2>&1)
    checkSuccess "Copying homeserver.yaml to $data_dir"

    result=$(copyResource "$app_name" "log.config" "data" | runInstallWrite -a "$logs_dir/$docker_log_file" 2>&1)
    checkSuccess "Copying log.config to $data_dir"

    local homeserver_file="$data_dir/homeserver.yaml"

    # Three independent secrets, each generated fresh. registration_shared_secret
    # can mint an account on this server, so it is as sensitive as an admin
    # password — it is why homeserver.yaml is chmod 600 below.
    local registration_secret macaroon_secret form_secret
    registration_secret=$(openssl rand -hex 32)
    macaroon_secret=$(openssl rand -hex 32)
    form_secret=$(openssl rand -hex 32)

    local enable_registration="false"
    [[ "$CFG_MATRIX_ENABLE_REGISTRATION" == "true" ]] && enable_registration="true"

    runFileOp sed -i "s|SYNAPSE_SERVER_NAME_PLACEHOLDER|$server_name|g" "$homeserver_file"
    runFileOp sed -i "s|SYNAPSE_DB_PASSWORD_PLACEHOLDER|$db_password|g" "$homeserver_file"
    runFileOp sed -i "s|SYNAPSE_REGISTRATION_SECRET_PLACEHOLDER|$registration_secret|g" "$homeserver_file"
    runFileOp sed -i "s|SYNAPSE_MACAROON_SECRET_PLACEHOLDER|$macaroon_secret|g" "$homeserver_file"
    runFileOp sed -i "s|SYNAPSE_FORM_SECRET_PLACEHOLDER|$form_secret|g" "$homeserver_file"
    runFileOp sed -i "s|SYNAPSE_ENABLE_REGISTRATION_PLACEHOLDER|$enable_registration|g" "$homeserver_file"
    checkSuccess "Writing homeserver.yaml (server_name=$server_name registration=$enable_registration)"

    runFileOp chmod 600 "$homeserver_file" "$data_dir/signing.key"
    runFileOp chown -R "$docker_install_user":"$docker_install_user" "$data_dir"
    checkSuccess "Restricting permissions on the Synapse secrets"

    # Element is a static bundle; config.json is the only thing that makes it
    # point at this homeserver rather than matrix.org.
    result=$(copyResource "$app_name" "element-config.json" "element" | runInstallWrite -a "$logs_dir/$docker_log_file" 2>&1)
    checkSuccess "Copying Element configuration to $app_dir/element"

    result=$(runFileOp mv "$app_dir/element/element-config.json" "$app_dir/element/config.json")
    checkSuccess "Renaming Element configuration to config.json"

    runFileOp sed -i "s|ELEMENT_HOMESERVER_PLACEHOLDER|$server_name|g" "$app_dir/element/config.json"
    runFileOp chown -R "$docker_install_user":"$docker_install_user" "$app_dir/element"
    checkSuccess "Pointing Element at https://$server_name"
}

matrix_install_post_start()
{
    local app_name="$1"

    ((menu_number++))
    echo ""
    echo "---- $menu_number. Creating the first Matrix admin account"
    echo ""

    # Synapse runs its database migrations on first boot, which on an empty
    # Postgres takes appreciably longer than the container takes to start.
    # /health answers only once it is actually serving.
    #
    # Probed with python rather than curl: the Synapse image is debian-slim with
    # no curl or wget in it, but python is what Synapse itself runs on, so it is
    # always there.
    local attempts=0
    while ((attempts < 60)); do
        if runFileOp docker exec matrix-synapse python -c \
            "import urllib.request; urllib.request.urlopen('http://localhost:8008/health', timeout=5)" >/dev/null 2>&1; then
            break
        fi
        sleep 2
        ((attempts++))
    done

    if ((attempts >= 60)); then
        isError "Synapse did not become ready in time — no admin account was created."
        isNotice "Check 'docker logs matrix-synapse'. Once it is up, create the account with:"
        isNotice "  docker exec -it matrix-synapse register_new_matrix_user -c /data/homeserver.yaml http://localhost:8008"
        return 0
    fi

    local admin_user="${CFG_MATRIX_ADMIN_USERNAME:-admin}"
    local admin_pass="${CFG_MATRIX_ADMIN_PASSWORD_1}"
    if [[ -z "$admin_pass" || "$admin_pass" == RANDOMIZEDPASSWORD* ]]; then
        isNotice "No admin password is set in matrix.config — skipping admin account creation."
        return 0
    fi

    # Idempotent in practice: on a reinstall over existing data the account
    # already exists and register_new_matrix_user fails with "User ID already
    # taken", which is not worth failing the install over.
    local result
    result=$(runFileOp docker exec matrix-synapse register_new_matrix_user \
        -u "$admin_user" -p "$admin_pass" -a \
        -c /data/homeserver.yaml http://localhost:8008 2>&1)
    if [[ "$result" == *"already taken"* ]]; then
        isNotice "Matrix admin '$admin_user' already exists — leaving the existing account alone."
    else
        checkSuccess "Creating Matrix admin account '$admin_user'"
    fi
}

matrix_install_post()
{
    local app_name="$1"
    local server_name
    server_name=$(_matrixServerName)
    local admin_user="${CFG_MATRIX_ADMIN_USERNAME:-admin}"

    echo ""
    isNotice "Matrix homeserver:"
    echo ""
    echo "      Server name  : ${server_name}"
    echo "      Your user ID : @${admin_user}:${server_name}"
    echo "      Password     : ${CFG_MATRIX_ADMIN_PASSWORD_1}"
    echo ""
    echo "      Sign in through the Element web interface, or any Matrix client"
    echo "      (Element mobile/desktop, FluffyChat, Nheko) using the server name"
    echo "      above."
    echo ""
    echo "      Registration is ${CFG_MATRIX_ENABLE_REGISTRATION:-false}. To invite"
    echo "      others while it stays closed, create their accounts with:"
    echo "        docker exec -it matrix-synapse register_new_matrix_user \\"
    echo "          -c /data/homeserver.yaml http://localhost:8008"
    echo ""
}