"""
Diagnostic script: check row counts at every layer of the pricing pipeline.

Run on prod via SSH:
    DUCKDB_PATH=/opt/padelnomics/data/lakehouse.duckdb uv run python scripts/check_pipeline.py

Or locally:
    DUCKDB_PATH=data/lakehouse.duckdb uv run python scripts/check_pipeline.py

Read-only — never writes to the database.
"""

import os
import sys

import duckdb

DUCKDB_PATH = os.environ.get("DUCKDB_PATH", "data/lakehouse.duckdb")

PIPELINE_TABLES = [
    ("staging", "stg_playtomic_availability"),
    ("foundation", "fct_availability_slot"),
    ("foundation", "dim_venue_capacity"),
    ("foundation", "fct_daily_availability"),
    ("serving", "venue_pricing_benchmarks"),
    ("serving", "pseo_city_pricing"),
]


def main():
    if not os.path.exists(DUCKDB_PATH):
        print(f"ERROR: {DUCKDB_PATH} not found")
        sys.exit(1)

    con = duckdb.connect(DUCKDB_PATH, read_only=True)

    print(f"Database: {DUCKDB_PATH}")
    print(f"DuckDB version: {con.execute('SELECT version()').fetchone()[0]}")
    print()

    # ── Row counts at each layer ──────────────────────────────────────────
    print("=" * 60)
    print("PIPELINE ROW COUNTS")
    print("=" * 60)

    for schema, table in PIPELINE_TABLES:
        # SQLMesh may use __<env> suffixed physical tables
        # Try the logical name first, then scan for physical tables
        candidates = [f"{schema}.{table}"]
        try:
            phys = con.execute(
                f"SELECT table_schema || '.' || table_name "
                f"FROM information_schema.tables "
                f"WHERE table_name LIKE '{table}%' "
                f"ORDER BY table_name"
            ).fetchall()
            for (name,) in phys:
                if name not in candidates:
                    candidates.append(name)
        except Exception:
            pass

        for fqn in candidates:
            try:
                (count,) = con.execute(f"SELECT COUNT(*) FROM {fqn}").fetchone()
                print(f"  {fqn:50s} {count:>10,} rows")
            except Exception as e:
                print(f"  {fqn:50s} ERROR: {e}")

    # ── Date range in fct_daily_availability ──────────────────────────────
    print()
    print("=" * 60)
    print("DATE RANGE: fct_daily_availability")
    print("=" * 60)

    try:
        row = con.execute("""
            SELECT
                MIN(snapshot_date) AS min_date,
                MAX(snapshot_date) AS max_date,
                COUNT(DISTINCT snapshot_date) AS distinct_days,
                CURRENT_DATE AS today,
                CURRENT_DATE - INTERVAL '30 days' AS window_start
            FROM foundation.fct_daily_availability
        """).fetchone()
        if row:
            min_date, max_date, days, today, window_start = row
            print(f"  Min snapshot_date:   {min_date}")
            print(f"  Max snapshot_date:   {max_date}")
            print(f"  Distinct days:       {days}")
            print(f"  Today:               {today}")
            print(f"  30-day window start: {window_start}")
            if max_date and str(max_date) < str(window_start):
                print()
                print("  *** ALL DATA IS OUTSIDE THE 30-DAY WINDOW ***")
                print("  This is why venue_pricing_benchmarks is empty.")
    except Exception as e:
        print(f"  ERROR: {e}")

    # ── HAVING filter impact in venue_pricing_benchmarks ──────────────────
    print()
    print("=" * 60)
    print("HAVING FILTER IMPACT (venue_pricing_benchmarks)")
    print("=" * 60)

    try:
        row = con.execute("""
            WITH venue_stats AS (
                SELECT
                    da.tenant_id,
                    da.country_code,
                    da.city,
                    COUNT(DISTINCT da.snapshot_date) AS days_observed
                FROM foundation.fct_daily_availability da
                WHERE TRY_CAST(da.snapshot_date AS DATE) >= CURRENT_DATE - INTERVAL '30 days'
                  AND da.occupancy_rate IS NOT NULL
                  AND da.occupancy_rate BETWEEN 0 AND 1.5
                GROUP BY da.tenant_id, da.country_code, da.city
            )
            SELECT
                COUNT(*) AS total_venues,
                COUNT(*) FILTER (WHERE days_observed >= 3) AS venues_passing_having,
                COUNT(*) FILTER (WHERE days_observed < 3) AS venues_failing_having,
                MAX(days_observed) AS max_days,
                MIN(days_observed) AS min_days
            FROM venue_stats
        """).fetchone()
        if row:
            total, passing, failing, max_d, min_d = row
            print(f"  Venues in 30-day window:          {total}")
            print(f"  Venues with >= 3 days (PASSING):  {passing}")
            print(f"  Venues with < 3 days (FILTERED):  {failing}")
            print(f"  Max days observed:                {max_d}")
            print(f"  Min days observed:                {min_d}")
            if total == 0:
                print()
                print("  *** NO VENUES IN 30-DAY WINDOW — check fct_daily_availability dates ***")
    except Exception as e:
        print(f"  ERROR: {e}")

    # ── Occupancy rate distribution ───────────────────────────────────────
    print()
    print("=" * 60)
    print("OCCUPANCY RATE DISTRIBUTION (fct_daily_availability)")
    print("=" * 60)

    try:
        rows = con.execute("""
            SELECT
                CASE
                    WHEN occupancy_rate IS NULL THEN 'NULL'
                    WHEN occupancy_rate < 0 THEN '< 0 (invalid)'
                    WHEN occupancy_rate > 1.5 THEN '> 1.5 (filtered)'
                    WHEN occupancy_rate <= 0.25 THEN '0 – 0.25'
                    WHEN occupancy_rate <= 0.50 THEN '0.25 – 0.50'
                    WHEN occupancy_rate <= 0.75 THEN '0.50 – 0.75'
                    ELSE '0.75 – 1.0+'
                END AS bucket,
                COUNT(*) AS cnt
            FROM foundation.fct_daily_availability
            GROUP BY 1
            ORDER BY 1
        """).fetchall()
        for bucket, cnt in rows:
            print(f"  {bucket:25s} {cnt:>10,}")
    except Exception as e:
        print(f"  ERROR: {e}")

    # ── dim_venue_capacity join coverage ──────────────────────────────────
    print()
    print("=" * 60)
    print("JOIN COVERAGE: fct_availability_slot → dim_venue_capacity")
    print("=" * 60)

    try:
        row = con.execute("""
            SELECT
                COUNT(DISTINCT a.tenant_id) AS slot_tenants,
                COUNT(DISTINCT c.tenant_id) AS capacity_tenants,
                COUNT(DISTINCT a.tenant_id) - COUNT(DISTINCT c.tenant_id) AS missing_capacity
            FROM foundation.fct_availability_slot a
            LEFT JOIN foundation.dim_venue_capacity c ON a.tenant_id = c.tenant_id
        """).fetchone()
        if row:
            slot_t, cap_t, missing = row
            print(f"  Tenants in fct_availability_slot: {slot_t}")
            print(f"  Tenants with capacity match:      {cap_t}")
            print(f"  Tenants missing capacity:         {missing}")
            if missing and missing > 0:
                print(f"  *** {missing} tenants dropped by INNER JOIN to dim_venue_capacity ***")
    except Exception as e:
        print(f"  ERROR: {e}")

    con.close()
    print()
    print("Done.")


if __name__ == "__main__":
    main()