#!/usr/bin/env bash
# Apply / drop ClickHouse DDL files in alphabetical order.
#
# Usage:
#   clickhouse_apply.sh up      apply *.up.sql in infra/clickhouse/
#   clickhouse_apply.sh down    apply *.down.sql in REVERSE order
#
# Talks to the HTTP(S) interface via curl -- no clickhouse-client binary needed.
# The SQL is POSTed as the raw body; ClickHouse parses the body when the URL
# has no ?query= parameter.
#
# Env:
#   CLICKHOUSE_ADDR     (default localhost:8123)
#   CLICKHOUSE_DB       (default cdp)
#   CLICKHOUSE_USER     (default default)
#   CLICKHOUSE_PASSWORD (default empty)
#   CLICKHOUSE_SECURE   (default 0; auto-on for port 8443)

set -euo pipefail

DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)/clickhouse"
ADDR="${CLICKHOUSE_ADDR:-localhost:8123}"
DB="${CLICKHOUSE_DB:-cdp}"
USER="${CLICKHOUSE_USER:-default}"
PASS="${CLICKHOUSE_PASSWORD:-}"
SECURE="${CLICKHOUSE_SECURE:-0}"

MODE="${1:-up}"

host="${ADDR%%:*}"
port="${ADDR##*:}"

case "$SECURE" in
    1|true|TRUE|yes) scheme="https" ;;
    *) [[ "$port" == "8443" ]] && scheme="https" || scheme="http" ;;
esac

URL_BASE="${scheme}://${host}:${port}/"

# post_sql posts a SQL string to ClickHouse. The query goes in the request
# body; URL params can carry session options like ?database=foo.
post_sql() {
    local sql="$1"
    local extra_param="${2:-}"
    local url="$URL_BASE"
    [[ -n "$extra_param" ]] && url="${URL_BASE}?${extra_param}"
    printf '%s' "$sql" | curl -sS --fail-with-body \
        -u "${USER}:${PASS}" \
        --data-binary @- \
        "$url"
    echo
}

post_sql_file() {
    # ClickHouse HTTP rejects multi-statements; split the file by `;` and post
    # each statement individually. Our DDL files use `--` line comments and
    # do not contain literal `;` inside strings, so a naive RS split is safe.
    local file="$1"
    local extra_param="${2:-}"
    local url="$URL_BASE"
    [[ -n "$extra_param" ]] && url="${URL_BASE}?${extra_param}"

    local tmpdir
    tmpdir=$(mktemp -d)

    awk -v dir="$tmpdir" '
        BEGIN { RS=";" ; count=0 }
        {
            stmt=$0
            gsub(/^[[:space:]\n\r]+|[[:space:]\n\r]+$/, "", stmt)
            if (stmt == "") next
            count++
            out=sprintf("%s/%04d.sql", dir, count)
            print stmt > out
        }
    ' "$file"

    local rc=0
    local s
    for s in "$tmpdir"/*.sql; do
        [[ -f "$s" ]] || continue
        if ! curl -sS --fail-with-body \
                -u "${USER}:${PASS}" \
                --data-binary "@${s}" \
                "$url"; then
            rc=1
            break
        fi
        echo
    done
    rm -rf "$tmpdir"
    return "$rc"
}

ensure_db() {
    post_sql "CREATE DATABASE IF NOT EXISTS \`${DB}\`"
}

run_sql_file() {
    local file="$1"
    echo ">>> applying $(basename "$file")"
    post_sql_file "$file" "database=${DB}"
}

case "$MODE" in
    up)
        ensure_db
        for f in $(ls "$DIR"/*.up.sql 2>/dev/null | sort); do
            run_sql_file "$f"
        done
        ;;
    down)
        for f in $(ls "$DIR"/*.down.sql 2>/dev/null | sort -r); do
            run_sql_file "$f"
        done
        ;;
    *)
        echo "usage: $0 {up|down}"
        exit 1
        ;;
esac

echo "done."