#!/bin/sh
# Runs in the MySQL client container, never in the application's web root.
set -eu

: "${MYSQL_HOST:?Missing MYSQL_HOST}"
: "${MYSQL_DATABASE:?Missing MYSQL_DATABASE}"
: "${MYSQL_USER:?Missing MYSQL_USER}"
: "${MYSQL_PASSWORD:?Missing MYSQL_PASSWORD}"
export MYSQL_PWD="$MYSQL_PASSWORD"

mysql_run() {
    mysql --protocol=TCP --host="$MYSQL_HOST" --port="${MYSQL_PORT:-3306}" \
        --user="$MYSQL_USER" --database="$MYSQL_DATABASE" \
        --batch --skip-column-names "$@"
}

fail() {
    printf '%s\n' "Database initialization refused: $*" >&2
    exit 1
}

require_tables() {
    count=$(mysql_run -e "SELECT COUNT(*) FROM information_schema.tables
        WHERE table_schema = DATABASE() AND table_type = 'BASE TABLE'
        AND table_name IN ($1)")
    [ "$count" = "$2" ] || fail "Required recruitment tables are missing. Review the database manually; no automatic reimport will be attempted."
}

marker=$(mysql_run -e "SELECT COUNT(*) FROM information_schema.tables
    WHERE table_schema = DATABASE() AND table_name = 'rec_bootstrap_state'")

if [ "$marker" = 1 ]; then
    status=$(mysql_run -e "SELECT status FROM rec_bootstrap_state WHERE id = 1")
    [ "$status" = imported ] || fail "A previous import did not finish. SQL imports are not transactional; inspect or restore this database before retrying."
    require_tables "'in_daper', 'in_soal', 'in_jawab'" 3
    printf '%s\n' 'Initial SQL was already imported; preserving existing data.'
    exit 0
fi

tables=$(mysql_run -e "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = DATABASE()")
if [ "$tables" != 0 ]; then
    # Adopt a previously initialized deployment, but reject a bare/partial schema.
    require_tables "'in_daper', 'in_soal', 'in_jawab', 'rec_admin', 'rec_exam_attempt', 'rec_exam_event', 'rec_candidate_login_guard'" 7
    printf '%s\n' 'Existing recruitment database detected; skipping SQL import.'
    exit 0
fi

sql_file=${DB_INIT_SQL_FILE:-/bootstrap/initial.sql}
[ -f "$sql_file" ] && [ -r "$sql_file" ] && [ -s "$sql_file" ] \
    || fail "The initial SQL file is missing, unreadable, or empty. Set DB_INIT_SQL_PATH to a trusted dump on the Docker host."

# The dump must not replace our safety marker with a previously imported one.
# Exclude this setup-only table when creating backups (see deployment guide).
if grep -iFq 'rec_bootstrap_state' "$sql_file"; then
    fail "The dump references the reserved rec_bootstrap_state table. Re-export without that table before importing."
fi

# Persist the in-progress marker BEFORE any DROP/CREATE statements in the dump.
# Do not use IF NOT EXISTS: concurrent first imports must not both proceed.
mysql_run -e "CREATE TABLE rec_bootstrap_state (
    id TINYINT UNSIGNED NOT NULL PRIMARY KEY,
    status VARCHAR(20) NOT NULL
) ENGINE=InnoDB;
INSERT INTO rec_bootstrap_state (id, status) VALUES (1, 'importing');"

printf '%s\n' 'Importing initial SQL into the empty database...'
mysql_run < "$sql_file"
require_tables "'in_daper', 'in_soal', 'in_jawab'" 3
mysql_run -e "UPDATE rec_bootstrap_state SET status = 'imported' WHERE id = 1"
printf '%s\n' 'Initial SQL import complete.'