"""Diagnostic script — run inside the pipeline container to test EES API access.

Usage:
    python scripts/diagnose_ees_ks4.py

Prints:
    - Whether the EES API is reachable and returns a valid release ID
    - Whether the ZIP download works
    - The list of CSV files inside the ZIP (so you can verify the filename match)
    - Row count and column names from the target CSV
"""

import io
import sys
import zipfile

import requests

CONTENT_API_BASE = "https://content.explore-education-statistics.service.gov.uk/api"
PUBLICATION_SLUG = "key-stage-4-performance"
TARGET_FILENAME = "performance_tables_schools"
TIMEOUT = 120


def main():
    # Step 1: get release ID
    url = f"{CONTENT_API_BASE}/publications/{PUBLICATION_SLUG}/releases/latest"
    print(f"\n[1] GET {url}")
    try:
        resp = requests.get(url, timeout=TIMEOUT)
        resp.raise_for_status()
    except Exception as e:
        print(f"    FAILED: {e}")
        sys.exit(1)

    data = resp.json()
    release_id = data.get("id")
    release_title = data.get("title", "?")
    print(f"    OK — release_id={release_id!r}  title={release_title!r}")

    if not release_id:
        print("    ERROR: no 'id' field in response. Response keys:", list(data.keys()))
        sys.exit(1)

    # Step 2: download the ZIP
    zip_url = f"{CONTENT_API_BASE}/releases/{release_id}/files"
    print(f"\n[2] GET {zip_url}  (ZIP download, may be slow...)")
    try:
        resp2 = requests.get(zip_url, timeout=300, stream=True)
        resp2.raise_for_status()
        content_type = resp2.headers.get("Content-Type", "?")
        content = resp2.content
        print(f"    OK — Content-Type={content_type!r}  size={len(content):,} bytes")
    except Exception as e:
        print(f"    FAILED: {e}")
        sys.exit(1)

    # Step 3: open as ZIP
    print(f"\n[3] Opening as ZIP...")
    try:
        zf = zipfile.ZipFile(io.BytesIO(content))
    except zipfile.BadZipFile as e:
        print(f"    FAILED — not a valid ZIP: {e}")
        print(f"    First 200 bytes of response: {content[:200]!r}")
        sys.exit(1)

    all_files = zf.namelist()
    csv_files = [n for n in all_files if n.endswith(".csv")]
    print(f"    OK — {len(all_files)} files total, {len(csv_files)} CSVs")
    print("    CSV files:")
    for f in csv_files:
        print(f"      {f}")

    # Step 4: find target file
    print(f"\n[4] Looking for file matching '{TARGET_FILENAME}'...")
    target = None
    for name in all_files:
        if TARGET_FILENAME in name and name.endswith(".csv"):
            target = name
            break

    if not target:
        print(f"    NOT FOUND. No CSV contains '{TARGET_FILENAME}'.")
        print("    All CSV names listed above — update _target_filename in tap.py to match.")
        sys.exit(1)

    print(f"    Found: {target!r}")

    # Step 5: read and report
    print(f"\n[5] Reading CSV...")
    import pandas as pd
    with zf.open(target) as f:
        df = pd.read_csv(f, dtype=str, keep_default_na=False, nrows=5)

    print(f"    Columns ({len(df.columns)}):")
    for col in df.columns:
        print(f"      {col!r}")

    print(f"\n[6] Filtering to school level and checking breakdown values...")
    with zf.open(target) as f:
        df_full = pd.read_csv(f, dtype=str, keep_default_na=False)

    if "geographic_level" in df_full.columns:
        school_df = df_full[df_full["geographic_level"] == "School"]
        print(f"    School-level rows: {len(school_df):,} / {len(df_full):,} total")
    else:
        school_df = df_full
        print(f"    No geographic_level column — total rows: {len(df_full):,}")

    for col in ["breakdown_topic", "breakdown", "sex"]:
        if col in school_df.columns:
            vals = school_df[col].value_counts().head(10)
            print(f"    {col} values: {vals.index.tolist()[:10]}")

    matching = school_df
    for col, val in [("breakdown_topic", "All pupils"), ("breakdown", "Total"), ("sex", "Total")]:
        if col in matching.columns:
            matching = matching[matching[col] == val]
    print(f"\n    Rows matching breakdown_topic='All pupils', breakdown='Total', sex='Total': {len(matching):,}")

    if len(matching) > 0:
        print("    LOOKS GOOD — data should flow through dbt once tap is fixed.")
    else:
        print("    WARNING — 0 rows match the dbt filter. Check breakdown values above.")

    print("\nDone.")


if __name__ == "__main__":
    main()