#!/usr/bin/env bash
set -euo pipefail

if [ "$#" -ne 1 ]; then
    echo "usage: $0 DE_VG250.gpkg"
    exit 1
fi

INPUT="$1"

if [ ! -f "$INPUT" ]; then
    echo "file not found: $INPUT"
    exit 1
fi

: "${DATABASE_URL:?DATABASE_URL must be set}"

echo "Available layers:"
ogrinfo "$INPUT" | sed -n '1,120p'

echo
echo "Inspecting vg250_krs..."
ogrinfo "$INPUT" vg250_krs -so

echo
echo "Importing only vg250_krs..."

# Remove an old failed import.
psql "$DATABASE_URL" <<'SQL'
DROP TABLE IF EXISTS vg250_krs_import CASCADE;
SQL

# IMPORTANT:
# The layer name is explicitly specified here.
ogr2ogr \
    -f PostgreSQL \
    "$DATABASE_URL" \
    "$INPUT" \
    vg250_krs \
    -nln vg250_krs_import \
    -nlt PROMOTE_TO_MULTI \
    -t_srs EPSG:4326 \
    -lco GEOMETRY_NAME=wkb_geometry \
    -overwrite

echo
echo "Source import completed."

echo
echo "Imported source columns:"
psql "$DATABASE_URL" <<'SQL'
SELECT
    column_name,
    data_type
FROM information_schema.columns
WHERE table_name = 'vg250_krs_import'
ORDER BY ordinal_position;
SQL

echo
echo "Creating county boundaries..."

psql "$DATABASE_URL" <<'SQL'
BEGIN;

TRUNCATE county_crossings;
TRUNCATE county_boundaries RESTART IDENTITY CASCADE;

INSERT INTO county_boundaries (
    name,
    geometry
)
SELECT
    COALESCE(
        NULLIF(TRIM(gen), ''),
        NULLIF(TRIM(bez), ''),
        NULLIF(TRIM(ars), ''),
        'unknown'
    ) AS name,

    ST_Multi(
        ST_CollectionExtract(
            ST_MakeValid(wkb_geometry),
            3
        )
    )::geometry(MultiPolygon, 4326) AS geometry

FROM vg250_krs_import

WHERE
    wkb_geometry IS NOT NULL
    AND NOT ST_IsEmpty(wkb_geometry);

COMMIT;
SQL

echo
echo "Removing temporary import table..."

psql "$DATABASE_URL" <<'SQL'
DROP TABLE vg250_krs_import;
SQL

echo
echo "Recreating spatial index..."

psql "$DATABASE_URL" <<'SQL'
DROP INDEX IF EXISTS county_boundaries_geometry_idx;

CREATE INDEX county_boundaries_geometry_idx
    ON county_boundaries
    USING GIST (geometry);

ANALYZE county_boundaries;
SQL

echo
echo "=========================================="
echo " Imported counties"
echo "=========================================="

psql "$DATABASE_URL" <<'SQL'
SELECT
    COUNT(*) AS total,
    COUNT(*) FILTER (WHERE geometry IS NOT NULL) AS with_geometry,
    COUNT(*) FILTER (WHERE ST_IsValid(geometry)) AS valid_geometry
FROM county_boundaries;
SQL

echo
echo "First 20 counties:"
echo

psql "$DATABASE_URL" <<'SQL'
SELECT
    id,
    name,
    ST_GeometryType(geometry) AS geometry_type,
    ST_SRID(geometry) AS srid
FROM county_boundaries
ORDER BY name
LIMIT 20;
SQL

echo
echo "Import completed successfully."