"""Brand layer (D-189, #827): generate_brands shell-out, TOML import, validation."""

import sqlite3
import sys
import tomllib
from pathlib import Path

from .errors import ImportAborted
from .paths import BRANDS_TOML, GENERATED_BRANDS_TOML, REPO_ROOT

# economy-db/ is hyphenated, so it is not importable as a package and cannot
# reach `tooling.core` by normal import. The bootstrap goes away with T-1272
# (the hyphen sweep); until then it is explicit rather than implied.
if str(REPO_ROOT) not in sys.path:
    sys.path.insert(0, str(REPO_ROOT))

VALID_BRAND_CATEGORIES: set[str] = {
    "terroir", "heritage_craft", "tech_premium", "cultural",
    "service_premium", "commodity_branded", "design_heritage", "platform_catalogue",
}
VALID_VALUE_TRAJECTORIES: set[str] = {"appreciating", "depreciating", "timeless"}
VALID_SCARCITY_CLASSES: set[str] = {"capped", "constrained", "scalable", "unlimited"}
VALID_BRAND_TIERS: set[str] = {"halo", "volume"}
VALID_CURRENCY_DENOMINATIONS: set[str] = {"tractus", "mark", "mixed", "sol_adjacent"}
VALID_PRICE_TIERS: set[str] = {"mass", "premium", "luxury", "flagship", "institutional"}


def regenerate_brands() -> None:
    """Run the Rust generate_brands binary to refresh generated_brands.toml.

    Invoked as the first step of import_economics' main flow so the TOML on disk
    always matches the current Rust source before the Python import reads it.
    This replaces the former split (tooling/generate-brands run separately by
    make regen-db) with a single, coherent brand pipeline owned by one stamp.

    The binary is built on demand and run with the default canonical seed=1;
    callers that need non-canonical seeds invoke it directly (experimentation
    only — committed output must be seed=1).

    This used to shell out to a `tooling/generate-brands` bash wrapper. The
    wrapper was one of three identical copies of build-if-missing-then-exec, so
    it was retired into `core.process.cargo_binary` (T-1286) and this calls that
    helper instead. Same binary, same seed, same output.
    """
    from tooling.core.errors import ReachError
    from tooling.core.process import cargo_binary

    print("  [pre/10] Running generate_brands (Rust) to refresh generated_brands.toml...")
    try:
        stdout = cargo_binary("generate_brands")
    except ReachError as exc:
        print(str(exc), file=sys.stderr)
        raise ImportAborted() from exc

    # Print the Rust binary's own summary lines (brands generated, coverage).
    # Indent so they fold under the pre-step heading.
    for line in stdout.splitlines():
        if line.strip():
            print(f"        {line}")


def _load_brand_file(path: Path) -> tuple[list, list]:
    """Load brand_products and brand_inputs from a TOML file. Returns empty lists if missing."""
    if not path.exists():
        return [], []
    with open(path, "rb") as f:
        data = tomllib.load(f)
    return data.get("brand_products", []), data.get("brand_inputs", [])


def import_brands(
    conn: sqlite3.Connection, dry_run: bool
) -> tuple[int, int]:
    """Import brand_products and brand_inputs from brands.toml and generated_brands.toml.

    Hand-authored brands (brands.toml) are imported first; generated brands
    (generated_brands.toml, produced by `tooling/generate-brands`) are merged in.
    Returns (n_products, n_inputs).
    """
    if not BRANDS_TOML.exists():
        print("        warning: brands.toml not found — brand layer skipped")
        return 0, 0

    products_authored, inputs_authored = _load_brand_file(BRANDS_TOML)
    products_generated, inputs_generated = _load_brand_file(GENERATED_BRANDS_TOML)

    if products_generated:
        print(f"        merging {len(products_generated)} generated brand_products from generated_brands.toml")

    products = products_authored + products_generated
    inputs = inputs_authored + inputs_generated

    product_rows: list[tuple] = []
    for p in products:
        product_rows.append((
            p["brand_product_id"],
            p["corp_id"],
            p["product_name"],
            p["brand_category"],
            p["value_trajectory"],
            p["scarcity_class"],
            p.get("product_subcategory"),
            p.get("base_premium_multiplier", 1.0),
            p.get("premium_floor", 0.0),
            p.get("origin_system"),
            int(p.get("terroir_locked", False)),
            p.get("currency_denomination", "tractus"),
            int(p.get("shadow_viable", False)),
            p["brand_tier"],
            p.get("halo_brand_id"),
            p.get("price_tier"),
        ))

    input_rows: list[tuple] = []
    for inp in inputs:
        input_rows.append((
            inp["brand_product_id"],
            inp["commodity_id"],
            inp["quantity"],
        ))

    if not dry_run:
        conn.executemany(
            """INSERT OR REPLACE INTO brand_products (
                brand_product_id, corp_id, product_name, brand_category,
                value_trajectory, scarcity_class, product_subcategory,
                base_premium_multiplier, premium_floor, origin_system,
                terroir_locked, currency_denomination, shadow_viable,
                brand_tier, halo_brand_id, price_tier
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)""",
            product_rows,
        )
        conn.executemany(
            """INSERT OR REPLACE INTO brand_inputs
               (brand_product_id, commodity_id, quantity) VALUES (?, ?, ?)""",
            input_rows,
        )

    return len(product_rows), len(input_rows)


def validate_brands(conn: sqlite3.Connection) -> list[str]:
    """Brand layer structural validation rules V-B01 through V-B06.

    V-B01: Every brand_products row has a valid corp_id (FK to corporations).
    V-B02: Every brand_inputs row has valid brand_product_id and commodity_id FKs.
    V-B03: Every halo brand has at least one brand_inputs entry (demand stub must consume).
    V-B04: Every volume tier must reference an existing halo brand_product_id.
    V-B05: No brand_product_id is used as halo_brand_id by a non-volume-tier product.
    V-B06: Every enum column (brand_category, value_trajectory, scarcity_class,
           brand_tier, currency_denomination) is a member of its VALID_* set.
    """
    errors: list[str] = []

    # V-B01: brand_products → corporations FK
    orphan_corps = conn.execute("""
        SELECT bp.brand_product_id, bp.corp_id
        FROM brand_products bp
        LEFT JOIN corporations c ON bp.corp_id = c.corp_id
        WHERE c.corp_id IS NULL
    """).fetchall()
    for pid, corp_id in orphan_corps:
        errors.append(
            f"V-B01: brand_product '{pid}' references unknown corp_id '{corp_id}'"
        )

    # V-B02: brand_inputs → brand_products and brand_inputs → commodities FKs
    orphan_inputs_bp = conn.execute("""
        SELECT bi.brand_product_id, bi.commodity_id
        FROM brand_inputs bi
        LEFT JOIN brand_products bp ON bi.brand_product_id = bp.brand_product_id
        WHERE bp.brand_product_id IS NULL
    """).fetchall()
    for pid, cid in orphan_inputs_bp:
        errors.append(
            f"V-B02: brand_inputs row ({pid}, {cid}) references unknown brand_product_id"
        )

    orphan_inputs_comm = conn.execute("""
        SELECT bi.brand_product_id, bi.commodity_id
        FROM brand_inputs bi
        LEFT JOIN commodities c ON bi.commodity_id = c.commodity_id
        WHERE c.commodity_id IS NULL
    """).fetchall()
    for pid, cid in orphan_inputs_comm:
        errors.append(
            f"V-B02: brand_inputs row ({pid}, {cid}) references unknown commodity_id '{cid}'"
        )

    # V-B03: every halo brand has at least one brand_inputs entry
    halo_no_inputs = conn.execute("""
        SELECT bp.brand_product_id
        FROM brand_products bp
        WHERE bp.brand_tier = 'halo'
          AND bp.brand_product_id NOT IN (SELECT brand_product_id FROM brand_inputs)
    """).fetchall()
    for (pid,) in halo_no_inputs:
        errors.append(
            f"V-B03: halo brand '{pid}' has no brand_inputs entries "
            f"(must consume at least one commodity as a demand node)"
        )

    # V-B04: volume tiers reference valid halo_brand_id
    volume_bad_halo = conn.execute("""
        SELECT bp.brand_product_id, bp.halo_brand_id
        FROM brand_products bp
        WHERE bp.brand_tier = 'volume'
          AND (bp.halo_brand_id IS NULL
               OR bp.halo_brand_id NOT IN (SELECT brand_product_id FROM brand_products))
    """).fetchall()
    for pid, halo_id in volume_bad_halo:
        errors.append(
            f"V-B04: volume brand '{pid}' has invalid halo_brand_id '{halo_id}'"
        )

    # V-B05: halo_brand_id must only point to halo-tier products
    halo_points_to_non_halo = conn.execute("""
        SELECT child.brand_product_id, child.halo_brand_id, parent.brand_tier
        FROM brand_products child
        JOIN brand_products parent ON child.halo_brand_id = parent.brand_product_id
        WHERE child.brand_tier = 'volume'
          AND parent.brand_tier != 'halo'
    """).fetchall()
    for child_id, halo_id, parent_tier in halo_points_to_non_halo:
        errors.append(
            f"V-B05: volume brand '{child_id}' points to '{halo_id}' "
            f"which has brand_tier='{parent_tier}', not 'halo'"
        )

    # V-B06: every enum column is in its VALID_* set. The SQL columns are
    # plain TEXT without CHECK constraints, so a typo like `terrior` would
    # otherwise silently import.
    enum_checks: list[tuple[str, set[str]]] = [
        ("brand_category", VALID_BRAND_CATEGORIES),
        ("value_trajectory", VALID_VALUE_TRAJECTORIES),
        ("scarcity_class", VALID_SCARCITY_CLASSES),
        ("brand_tier", VALID_BRAND_TIERS),
        ("currency_denomination", VALID_CURRENCY_DENOMINATIONS),
        ("price_tier", VALID_PRICE_TIERS),
    ]
    for column, valid_set in enum_checks:
        bad = conn.execute(
            f"SELECT brand_product_id, {column} FROM brand_products"
        ).fetchall()
        for pid, value in bad:
            if value is None:
                continue  # nullable columns (e.g. price_tier) may be unset
            if value not in valid_set:
                errors.append(
                    f"V-B06: brand_product '{pid}' has {column}='{value}' — "
                    f"must be one of {sorted(valid_set)}"
                )

    return errors