import os

from sqlmesh import macro


@macro()
def padelnomics_glob(evaluator) -> str:
    """Return a quoted glob path for all padelnomics CSV gz files under LANDING_DIR.

    Used in raw models: SELECT * FROM read_csv(@padelnomics_glob(), ...)

    The LANDING_DIR variable is read from the SQLMesh config variables block first,
    then falls back to the LANDING_DIR environment variable, then to 'data/landing'.
    """
    landing_dir = evaluator.var("LANDING_DIR") or os.environ.get("LANDING_DIR", "data/landing")
    return f"'{landing_dir}/padelnomics/**/*.csv.gz'"


# ── Country code helpers ─────────────────────────────────────────────────────
# Shared lookup used by dim_cities and dim_locations.

_COUNTRY_NAMES = {
    "DE": "Germany", "ES": "Spain", "GB": "United Kingdom",
    "FR": "France", "IT": "Italy", "PT": "Portugal",
    "AT": "Austria", "CH": "Switzerland", "NL": "Netherlands",
    "BE": "Belgium", "SE": "Sweden", "NO": "Norway",
    "DK": "Denmark", "FI": "Finland", "US": "United States",
    "AR": "Argentina", "MX": "Mexico", "AE": "UAE",
    "AU": "Australia", "IE": "Ireland",
}


def _country_case(col: str) -> str:
    """Build a CASE expression mapping ISO 3166-1 alpha-2 → English name."""
    whens = "\n    ".join(
        f"WHEN '{code}' THEN '{name}'" for code, name in _COUNTRY_NAMES.items()
    )
    return f"CASE {col}\n    {whens}\n    ELSE {col}\n  END"


@macro()
def country_name(evaluator, code_col) -> str:
    """CASE expression: country code → English name.

    Usage in SQL: @country_name(vc.country_code) AS country_name_en
    """
    return _country_case(str(code_col))


@macro()
def country_slug(evaluator, code_col) -> str:
    """CASE expression: country code → URL-safe slug (lowercased, spaces → dashes).

    Usage in SQL: @country_slug(vc.country_code) AS country_slug
    """
    return f"LOWER(REGEXP_REPLACE({_country_case(str(code_col))}, '[^a-zA-Z0-9]+', '-'))"


@macro()
def normalize_eurostat_country(evaluator, code_col) -> str:
    """Normalize Eurostat country codes to ISO 3166-1 alpha-2: EL→GR, UK→GB.

    Usage in SQL: @normalize_eurostat_country(geo_code) AS country_code
    """
    col = str(code_col)
    return f"CASE {col} WHEN 'EL' THEN 'GR' WHEN 'UK' THEN 'GB' ELSE {col} END"


@macro()
def normalize_eurostat_nuts(evaluator, code_col) -> str:
    """Normalize NUTS code prefix: EL→GR, UK→GB, preserving the suffix.

    Usage in SQL: @normalize_eurostat_nuts(geo_code) AS nuts_code
    """
    col = str(code_col)
    return (
        f"CASE"
        f" WHEN {col} LIKE 'EL%' THEN 'GR' || SUBSTR({col}, 3)"
        f" WHEN {col} LIKE 'UK%' THEN 'GB' || SUBSTR({col}, 3)"
        f" ELSE {col}"
        f" END"
    )


@macro()
def slugify(evaluator, col) -> str:
    """URL-safe slug: lowercase → ß→ss → strip accents → non-alnum to dashes → trim.

    Usage in SQL: @slugify(city) AS city_slug
    """
    c = str(col)
    return (
        f"TRIM(REGEXP_REPLACE("
        f"LOWER(STRIP_ACCENTS(REPLACE(LOWER({c}), 'ß', 'ss'))), "
        f"'[^a-z0-9]+', '-'"
        f"), '-')"
    )


@macro()
def infer_country_from_coords(evaluator, lat_col, lon_col) -> str:
    """Infer ISO country code from lat/lon using bounding boxes for 8 European markets.

    Usage in SQL:
      COALESCE(NULLIF(TRIM(UPPER(country_code)), ''),
               @infer_country_from_coords(lat, lon)) AS country_code
    """
    lat = str(lat_col)
    lon = str(lon_col)
    return (
        f"CASE"
        f" WHEN {lat} BETWEEN 47.27 AND 55.06 AND {lon} BETWEEN  5.87 AND 15.04 THEN 'DE'"
        f" WHEN {lat} BETWEEN 35.95 AND 43.79 AND {lon} BETWEEN -9.39 AND  4.33 THEN 'ES'"
        f" WHEN {lat} BETWEEN 49.90 AND 60.85 AND {lon} BETWEEN -8.62 AND  1.77 THEN 'GB'"
        f" WHEN {lat} BETWEEN 41.36 AND 51.09 AND {lon} BETWEEN -5.14 AND  9.56 THEN 'FR'"
        f" WHEN {lat} BETWEEN 45.46 AND 47.80 AND {lon} BETWEEN  5.96 AND 10.49 THEN 'CH'"
        f" WHEN {lat} BETWEEN 46.37 AND 49.02 AND {lon} BETWEEN  9.53 AND 17.16 THEN 'AT'"
        f" WHEN {lat} BETWEEN 36.35 AND 47.09 AND {lon} BETWEEN  6.62 AND 18.51 THEN 'IT'"
        f" WHEN {lat} BETWEEN 37.00 AND 42.15 AND {lon} BETWEEN -9.50 AND -6.19 THEN 'PT'"
        f" ELSE NULL"
        f" END"
    )