"""
Migration idempotente per sandbox.
Base.metadata.create_all() crea solo tabelle mancanti, non colonne aggiuntive.
Qui gestiamo ALTER TABLE ADD COLUMN IF NOT EXISTS per l'evoluzione dello schema.

Ogni migration è una stringa SQL che puo essere eseguita piu volte senza errori.
"""
from sqlalchemy import text
import logging

log = logging.getLogger("rendicontazione-api.migrations")


MIGRATIONS = [
    # 2026-04-18: colonne file upload su remission_invoice
    """
    ALTER TABLE gepafin_rendic.remission_invoice
        ADD COLUMN IF NOT EXISTS storage_path varchar(1024),
        ADD COLUMN IF NOT EXISTS mime varchar(128),
        ADD COLUMN IF NOT EXISTS size_bytes bigint,
        ADD COLUMN IF NOT EXISTS sha256 varchar(64),
        ADD COLUMN IF NOT EXISTS uploaded_by integer,
        ADD COLUMN IF NOT EXISTS uploaded_at timestamptz;
    """,
    # 2026-04-18: colonne file upload su remission_ula_employee
    """
    ALTER TABLE gepafin_rendic.remission_ula_employee
        ADD COLUMN IF NOT EXISTS storage_path varchar(1024),
        ADD COLUMN IF NOT EXISTS mime varchar(128),
        ADD COLUMN IF NOT EXISTS size_bytes bigint,
        ADD COLUMN IF NOT EXISTS sha256 varchar(64),
        ADD COLUMN IF NOT EXISTS uploaded_by integer,
        ADD COLUMN IF NOT EXISTS uploaded_at timestamptz;
    """,
    # 2026-04-18: colonne file upload su remission_document
    """
    ALTER TABLE gepafin_rendic.remission_document
        ADD COLUMN IF NOT EXISTS storage_path varchar(1024),
        ADD COLUMN IF NOT EXISTS mime varchar(128),
        ADD COLUMN IF NOT EXISTS size_bytes bigint,
        ADD COLUMN IF NOT EXISTS sha256 varchar(64),
        ADD COLUMN IF NOT EXISTS uploaded_by integer;
    """,
    # 2026-04-18 v2: multi-tranche su remission_practice
    # DROP UNIQUE su application_id (permette piu tranche per stessa domanda)
    # aggiunge sequence_number, period_label, suggested_instructor_id
    # nuova UNIQUE (application_id, sequence_number)
    # partial index su assigned_instructor_id IS NULL per coda "da assegnare"
    """
    ALTER TABLE gepafin_rendic.remission_practice
        DROP CONSTRAINT IF EXISTS uq_remission_practice_application;
    ALTER TABLE gepafin_rendic.remission_practice
        ADD COLUMN IF NOT EXISTS sequence_number integer NOT NULL DEFAULT 1,
        ADD COLUMN IF NOT EXISTS period_label varchar(100),
        ADD COLUMN IF NOT EXISTS suggested_instructor_id integer;
    DO $$
    BEGIN
        IF NOT EXISTS (
            SELECT 1 FROM pg_constraint
            WHERE conname = 'uq_remission_practice_app_seq'
              AND conrelid = 'gepafin_rendic.remission_practice'::regclass
        ) THEN
            ALTER TABLE gepafin_rendic.remission_practice
                ADD CONSTRAINT uq_remission_practice_app_seq UNIQUE (application_id, sequence_number);
        END IF;
    END$$;
    CREATE INDEX IF NOT EXISTS idx_remission_practice_unassigned
        ON gepafin_rendic.remission_practice(assigned_instructor_id)
        WHERE assigned_instructor_id IS NULL;
    """,
    # 2026-04-18 v2: tabella custom checks
    # allineata allo storage adapter esistente (storage_path + mime + size + sha256)
    # NON segue le specs RAG p1 che usavano document_filename (v1 obsoleta)
    """
    CREATE TABLE IF NOT EXISTS gepafin_rendic.remission_custom_check_value (
        id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
        practice_id uuid NOT NULL REFERENCES gepafin_rendic.remission_practice(id) ON DELETE CASCADE,
        check_code varchar(64) NOT NULL,
        beneficiary_declared boolean NOT NULL DEFAULT false,
        declared_at timestamptz,
        storage_path varchar(1024),
        mime varchar(128),
        size_bytes bigint,
        sha256 varchar(64),
        document_uploaded_at timestamptz,
        uploaded_by integer,
        verification_status varchar(20) NOT NULL DEFAULT 'PENDING',
        verification_notes text,
        verified_by integer,
        verified_at timestamptz,
        created_at timestamptz NOT NULL DEFAULT NOW(),
        updated_at timestamptz NOT NULL DEFAULT NOW(),
        CONSTRAINT uq_custom_check_practice_code UNIQUE (practice_id, check_code)
    );
    CREATE INDEX IF NOT EXISTS idx_custom_check_practice
        ON gepafin_rendic.remission_custom_check_value(practice_id);
    """,
]


def run_migrations(engine) -> None:
    """Esegue tutte le migration in transazione. Log su ciascuna."""
    with engine.begin() as conn:
        for i, sql in enumerate(MIGRATIONS, 1):
            try:
                conn.execute(text(sql))
                log.info(f"migration {i}/{len(MIGRATIONS)} OK")
            except Exception as e:
                log.error(f"migration {i} FAILED: {e}")
                raise