from pathlib import Path

import typer

from tht.cli._guards import (
    has_vector_write_rest,
    require_server_profile,
    require_vector_write_allowed,
)
from tht.cli.config_cmd import CONFIG_OPT
from tht.cli.schema_cmd import _load_config_or_exit, annotations_path, physical_path
from tht.ports.vector import VectorWriteRecord
from tht.vectorstore.store import SyncStats, content_hash

vector_app = typer.Typer(help="Indice semantico pgvector (derivato, rigenerabile)")


def make_embedder(embeddings_cfg):
    """Factory del client embeddings (monkeypatchabile nei test)."""
    from tht.vectorstore.embeddings import OllamaEmbeddings

    return OllamaEmbeddings(embeddings_cfg)


def require_vector_cfg(cfg):
    missing = []
    if cfg.embeddings is None:
        missing.append("embeddings")
    if cfg.vector_db is None and not has_vector_write_rest(cfg):
        missing.append("vector_db o vector_write_rest")
    if missing:
        typer.secho(
            f"ERRORE: sezioni mancanti nel workspace yaml: {', '.join(missing)}.",
            fg=typer.colors.RED, err=True,
        )
        raise typer.Exit(code=1)


def require_direct_vector_cfg(cfg):
    missing = [k for k in ("vector_db", "embeddings") if getattr(cfg, k) is None]
    if missing:
        typer.secho(
            f"ERRORE: sezioni mancanti nel workspace yaml: {', '.join(missing)}.",
            fg=typer.colors.RED, err=True,
        )
        raise typer.Exit(code=1)


def open_store(cfg, table: str):
    """Writer table-scoped per il LOADING.

    Sul server preferisce la connessione diretta. In profilo workstation usa `vector_write_rest`
    se configurato, con upsert remoto non distruttivo.
    """
    from tht.adapters.factory import build_vector_loader

    return build_vector_loader(cfg, table)


def open_searcher(cfg):
    """Searcher per la LETTURA (similarity search): via REST se `vector_rest` è configurato,
    altrimenti connessione diretta (dev/test)."""
    from tht.adapters.factory import build_vector_store
    from tht.vectorstore.reader import tables_for_kinds

    store = build_vector_store(cfg)

    class AdapterSearcher:
        def search(self, query_vec, top_n=10, kinds=None, metadata_filter=None):
            return store.search(
                tables_for_kinds(kinds), query_vec, limit=top_n, kinds=kinds,
                metadata_filter=metadata_filter,
            )

    return AdapterSearcher()


def sync_canonical_records(collection, records, *, store, embedder):
    kinds = sorted({record.kind for record in records})
    existing = store.existing_hashes(collection, kinds)
    pending = []
    stats = SyncStats()
    changed = []
    for record in records:
        hashed = content_hash(record.content)
        current = existing.get(record.id)
        if current == hashed:
            stats.unchanged += 1
            continue
        changed.append((record, hashed, current is None))
    if changed:
        embeddings = embedder.embed_documents([record.content for record, *_ in changed])
        for (record, hashed, is_added), embedding in zip(changed, embeddings, strict=True):
            pending.append(VectorWriteRecord(record=record, embedding=embedding, content_hash=hashed))
            if is_added:
                stats.added += 1
            else:
                stats.updated += 1
        store.upsert(collection, pending)
    return stats


def _print_stats(stats) -> None:
    typer.secho(
        f"OK: {stats.added} nuovi, {stats.updated} aggiornati, "
        f"{stats.deleted} rimossi, {stats.unchanged} invariati",
        fg=typer.colors.GREEN,
    )


@vector_app.command("init")
def init_cmd(
    config: Path = CONFIG_OPT,
    skip_ollama_check: bool = typer.Option(
        False, "--skip-ollama-check", help="Non verificare la raggiungibilita' di Ollama."
    ),
) -> None:
    """Crea schema e tabella pgvector (idempotente) e verifica le connessioni."""
    from sqlalchemy.exc import OperationalError

    from tht.vectorstore.embeddings import EmbeddingsError
    from tht.vectorstore.reader import ALL_TABLES

    cfg = _load_config_or_exit(config)
    require_server_profile(cfg, "vector init")
    require_direct_vector_cfg(cfg)
    try:
        for table in ALL_TABLES:
            open_store(cfg, table).init_schema()
    except OperationalError as e:
        typer.secho(f"ERRORE connessione pgvector: {e.orig}", fg=typer.colors.RED, err=True)
        raise typer.Exit(code=1)
    if not skip_ollama_check:
        try:
            make_embedder(cfg.embeddings).embed_query("ping")
        except EmbeddingsError as e:
            typer.secho(f"ERRORE: {e}", fg=typer.colors.RED, err=True)
            raise typer.Exit(code=1)
    typer.secho(
        f"OK: schema {cfg.vector_db.db_schema} pronto (tabelle: {', '.join(ALL_TABLES)}) su "
        f"{cfg.vector_db.host}:{cfg.vector_db.port}", fg=typer.colors.GREEN,
    )


@vector_app.command("index-schema")
def index_schema_cmd(config: Path = CONFIG_OPT) -> None:
    """Embedda e sincronizza i record schema (tabelle e colonne) da mschema."""
    from tht.mschema.models import Annotations, PhysicalSchema
    from tht.vectorstore.records import schema_records

    cfg = _load_config_or_exit(config)
    require_vector_write_allowed(cfg, "vector index-schema")
    require_vector_cfg(cfg)
    phys_file = physical_path(cfg)
    if not phys_file.exists():
        typer.secho(
            f"ERRORE: {phys_file} non trovato. Esegui prima `tht schema introspect`.",
            fg=typer.colors.RED, err=True,
        )
        raise typer.Exit(code=1)
    physical = PhysicalSchema.from_yaml(phys_file)
    annotations = Annotations.from_yaml(annotations_path(cfg))
    records = schema_records(physical, annotations)
    from tht.adapters.factory import build_vector_store

    stats = sync_canonical_records(
        "schema_records",
        records,
        store=build_vector_store(cfg, require_write=True),
        embedder=make_embedder(cfg.embeddings),
    )
    _print_stats(stats)