from sqlalchemy import inspect, text

from app.db.base import engine
from app.db.dialect import bool_literal


def run_migrations() -> None:
    inspector = inspect(engine)

    if "pomodoro_sessions" in inspector.get_table_names():
        columns = {col["name"] for col in inspector.get_columns("pomodoro_sessions")}
        with engine.begin() as conn:
            if "phase" not in columns:
                conn.execute(
                    text("ALTER TABLE pomodoro_sessions ADD COLUMN phase VARCHAR(32) DEFAULT 'work'")
                )
            if "completion_notified" not in columns:
                conn.execute(
                    text(
                        "ALTER TABLE pomodoro_sessions "
                        f"ADD COLUMN completion_notified BOOLEAN DEFAULT {bool_literal(engine, False)}"
                    )
                )

    if "messages" in inspector.get_table_names():
        columns = {col["name"] for col in inspector.get_columns("messages")}
        with engine.begin() as conn:
            if "reasoning_json" not in columns:
                conn.execute(text("ALTER TABLE messages ADD COLUMN reasoning_json TEXT"))

    if "pomodoro_cycles" not in inspector.get_table_names():
        _migrate_documents(inspector)
        return

    columns = {col["name"] for col in inspector.get_columns("pomodoro_cycles")}
    with engine.begin() as conn:
        if "chat_notify_seq" not in columns:
            conn.execute(
                text("ALTER TABLE pomodoro_cycles ADD COLUMN chat_notify_seq INTEGER DEFAULT 0")
            )

    _migrate_documents(inspector)


def _add_column_if_missing(table: str, columns: set[str], column: str, ddl: str) -> None:
    if column in columns:
        return
    with engine.begin() as conn:
        conn.execute(text(ddl))


def _migrate_documents(inspector) -> None:
    table_names = inspector.get_table_names()
    if "documents" in table_names:
        columns = {col["name"] for col in inspector.get_columns("documents")}
        _add_column_if_missing(
            "documents",
            columns,
            "mime_type",
            "ALTER TABLE documents ADD COLUMN mime_type VARCHAR(128) DEFAULT ''",
        )
        _add_column_if_missing(
            "documents",
            columns,
            "chunk_count",
            "ALTER TABLE documents ADD COLUMN chunk_count INTEGER DEFAULT 0",
        )
        _add_column_if_missing(
            "documents",
            columns,
            "index_status",
            "ALTER TABLE documents ADD COLUMN index_status VARCHAR(32) DEFAULT 'indexed'",
        )

    if "document_chunks" in table_names:
        columns = {col["name"] for col in inspector.get_columns("document_chunks")}
        _add_column_if_missing(
            "document_chunks",
            columns,
            "source_filename",
            "ALTER TABLE document_chunks ADD COLUMN source_filename VARCHAR(255) DEFAULT ''",
        )
        _add_column_if_missing(
            "document_chunks",
            columns,
            "mime_type",
            "ALTER TABLE document_chunks ADD COLUMN mime_type VARCHAR(128) DEFAULT ''",
        )
        _add_column_if_missing(
            "document_chunks",
            columns,
            "page_start",
            "ALTER TABLE document_chunks ADD COLUMN page_start INTEGER",
        )
        _add_column_if_missing(
            "document_chunks",
            columns,
            "page_end",
            "ALTER TABLE document_chunks ADD COLUMN page_end INTEGER",
        )
        _add_column_if_missing(
            "document_chunks",
            columns,
            "section_title",
            "ALTER TABLE document_chunks ADD COLUMN section_title VARCHAR(500) DEFAULT ''",
        )
        _add_column_if_missing(
            "document_chunks",
            columns,
            "section_path",
            "ALTER TABLE document_chunks ADD COLUMN section_path TEXT DEFAULT ''",
        )
        _add_column_if_missing(
            "document_chunks",
            columns,
            "paragraph_index",
            "ALTER TABLE document_chunks ADD COLUMN paragraph_index INTEGER",
        )
        _add_column_if_missing(
            "document_chunks",
            columns,
            "source_ref",
            "ALTER TABLE document_chunks ADD COLUMN source_ref VARCHAR(500) DEFAULT ''",
        )