"""Change serialization of signals to allow for function calls."""

import json

from sqlglot import exp, parse_one

from sqlmesh.utils.migration import index_text_type, blob_text_type


def migrate_schemas(engine_adapter, schema, **kwargs):  # type: ignore
    pass


def migrate_rows(engine_adapter, schema, **kwargs):  # type: ignore
    import pandas as pd

    snapshots_table = "_snapshots"
    index_type = index_text_type(engine_adapter.dialect)
    if schema:
        snapshots_table = f"{schema}.{snapshots_table}"

    new_snapshots = []

    signal_change = False
    for (
        name,
        identifier,
        version,
        snapshot,
        kind_name,
        updated_ts,
        unpaused_ts,
        ttl_ms,
        unrestorable,
    ) in engine_adapter.fetchall(
        exp.select(
            "name",
            "identifier",
            "version",
            "snapshot",
            "kind_name",
            "updated_ts",
            "unpaused_ts",
            "ttl_ms",
            "unrestorable",
        ).from_(snapshots_table),
        quote_identifiers=True,
    ):
        parsed_snapshot = json.loads(snapshot)
        node = parsed_snapshot["node"]
        signals = node.get("signals")

        if signals:
            signal_change = True
            node["signals"] = []

            for signal in signals:
                node["signals"].append(
                    (
                        "",
                        {
                            eq.left.name: eq.right.sql()
                            for eq in parse_one(signal, into=exp.Tuple).expressions
                        },
                    )
                )

        new_snapshots.append(
            {
                "name": name,
                "identifier": identifier,
                "version": version,
                "snapshot": json.dumps(parsed_snapshot),
                "kind_name": kind_name,
                "updated_ts": updated_ts,
                "unpaused_ts": unpaused_ts,
                "ttl_ms": ttl_ms,
                "unrestorable": unrestorable,
            }
        )

    if signal_change and new_snapshots:
        engine_adapter.delete_from(snapshots_table, "TRUE")
        blob_type = blob_text_type(engine_adapter.dialect)

        engine_adapter.insert_append(
            snapshots_table,
            pd.DataFrame(new_snapshots),
            target_columns_to_types={
                "name": exp.DataType.build(index_type),
                "identifier": exp.DataType.build(index_type),
                "version": exp.DataType.build(index_type),
                "snapshot": exp.DataType.build(blob_type),
                "kind_name": exp.DataType.build(index_type),
                "updated_ts": exp.DataType.build("bigint"),
                "unpaused_ts": exp.DataType.build("bigint"),
                "ttl_ms": exp.DataType.build("bigint"),
                "unrestorable": exp.DataType.build("boolean"),
            },
        )
