"""Tests para el pipeline duckdb_to_postgres.

Los tests que tocan PostgreSQL hacen skip elegante si no hay PG_TEST_DSN. El mapeo
de tipos y la construccion de DDL se prueban sin Postgres (logica pura interna).
"""

import os
import sys

import pytest

sys.path.insert(0, os.path.dirname(__file__))

import duckdb  # noqa: E402

from duckdb_to_postgres import (  # noqa: E402
    _build_ddl,
    _map_duckdb_type_to_pg,
    duckdb_to_postgres,
)

PG_DSN = os.environ.get("PG_TEST_DSN")


# --- Tests sin Postgres: mapeo de tipos y DDL ---


def test_map_tipos_duckdb_a_postgres():
    assert _map_duckdb_type_to_pg("BIGINT") == "BIGINT"
    assert _map_duckdb_type_to_pg("INTEGER") == "BIGINT"
    assert _map_duckdb_type_to_pg("DOUBLE") == "DOUBLE PRECISION"
    assert _map_duckdb_type_to_pg("FLOAT") == "DOUBLE PRECISION"
    assert _map_duckdb_type_to_pg("VARCHAR") == "TEXT"
    assert _map_duckdb_type_to_pg("TEXT") == "TEXT"
    assert _map_duckdb_type_to_pg("BOOLEAN") == "BOOLEAN"
    assert _map_duckdb_type_to_pg("DATE") == "DATE"
    assert _map_duckdb_type_to_pg("TIMESTAMP") == "TIMESTAMP"
    # Parametrizados normalizan al tipo base.
    assert _map_duckdb_type_to_pg("DECIMAL(10,2)") == "TEXT"
    assert _map_duckdb_type_to_pg("VARCHAR(50)") == "TEXT"
    # Desconocido -> TEXT (con posible perdida de tipado).
    assert _map_duckdb_type_to_pg("STRUCT(a INT)") == "TEXT"


def test_build_ddl_con_pk_y_drop():
    cols = [
        {"name": "id", "type": "BIGINT"},
        {"name": "nombre", "type": "VARCHAR"},
    ]
    ddl = _build_ddl("destino", cols, ["id"], drop_first=True)
    assert "DROP TABLE IF EXISTS \"destino\";" in ddl
    assert 'CREATE TABLE IF NOT EXISTS "destino"' in ddl
    assert '"id" BIGINT' in ddl
    assert '"nombre" TEXT' in ddl
    assert 'PRIMARY KEY ("id")' in ddl


def test_build_ddl_sin_pk_ni_drop():
    cols = [{"name": "x", "type": "DOUBLE"}]
    ddl = _build_ddl("t", cols, [], drop_first=False)
    assert "DROP TABLE" not in ddl
    assert '"x" DOUBLE PRECISION' in ddl
    assert "PRIMARY KEY" not in ddl


# --- Validaciones de entrada (sin Postgres) ---


def test_identificador_tabla_invalido(tmp_path):
    res = duckdb_to_postgres(str(tmp_path / "x.duckdb"), "t; DROP", "dsn")
    assert res["status"] == "error"
    assert "invalid table identifier" in res["error"]


def test_mode_invalido(tmp_path):
    db = tmp_path / "x.duckdb"
    con = duckdb.connect(str(db))
    con.execute("CREATE TABLE t (id BIGINT)")
    con.close()
    res = duckdb_to_postgres(str(db), "t", "dsn", mode="merge")
    assert res["status"] == "error"
    assert "invalid mode" in res["error"]


# --- Tests end-to-end con Postgres ---


@pytest.mark.skipif(not PG_DSN, reason="PG_TEST_DSN no definido")
def test_replace_sincroniza_filas(tmp_path):
    db = tmp_path / "src.duckdb"
    con = duckdb.connect(str(db))
    con.execute("CREATE TABLE ventas (id BIGINT, region VARCHAR, total DOUBLE)")
    con.execute(
        "INSERT INTO ventas VALUES (1,'norte',10.5),(2,'sur',20.0),(3,'norte',5.25)"
    )
    con.close()
    pgt = "test_duckdb_to_pg_ventas"
    res = duckdb_to_postgres(str(db), "ventas", PG_DSN, pg_table=pgt, mode="replace")
    assert res["status"] == "ok", res
    assert res["pg_table"] == pgt
    assert res["rows_synced"] == 3
    assert res["created"] is True

    import psycopg2

    conn = psycopg2.connect(PG_DSN)
    try:
        with conn.cursor() as cur:
            cur.execute(f'SELECT COUNT(*) FROM "{pgt}"')
            assert cur.fetchone()[0] == 3
            cur.execute(f'DROP TABLE IF EXISTS "{pgt}"')
        conn.commit()
    finally:
        conn.close()


@pytest.mark.skipif(not PG_DSN, reason="PG_TEST_DSN no definido")
def test_upsert_idempotente_con_key_cols(tmp_path):
    db = tmp_path / "src.duckdb"
    con = duckdb.connect(str(db))
    con.execute("CREATE TABLE u (id BIGINT, v VARCHAR)")
    con.execute("INSERT INTO u VALUES (1,'a'),(2,'b')")
    con.close()
    pgt = "test_duckdb_to_pg_upsert"
    r1 = duckdb_to_postgres(
        str(db), "u", PG_DSN, pg_table=pgt, mode="replace", key_cols=["id"]
    )
    assert r1["status"] == "ok", r1
    # Re-sync en modo upsert: no debe duplicar (idempotente).
    r2 = duckdb_to_postgres(
        str(db), "u", PG_DSN, pg_table=pgt, mode="upsert", key_cols=["id"]
    )
    assert r2["status"] == "ok", r2

    import psycopg2

    conn = psycopg2.connect(PG_DSN)
    try:
        with conn.cursor() as cur:
            cur.execute(f'SELECT COUNT(*) FROM "{pgt}"')
            assert cur.fetchone()[0] == 2
            cur.execute(f'DROP TABLE IF EXISTS "{pgt}"')
        conn.commit()
    finally:
        conn.close()