zer-schema 1.0.3

/// Example: schema registry warm-start workflow.
///
/// Demonstrates the full pipeline startup decision loop:
/// 1. Train on BRP Q1 → save `ModelArtifact` to registry
/// 2. Arrive with BRP Q2 (same schema) → WarmLoad (skip EM entirely)
/// 3. Arrive with BRP + one new field (verblijfstitel) → WarmStart (2–3 EM iters)
/// 4. Arrive with SIM subscriber schema → ColdStart (full EM from priors)
/// 5. Demonstrate `list_all` and `delete`
use zer_core::{
    record::{FieldValue, Record},
    schema::{FieldKind, SchemaBuilder},
    scoring::ModelParams,
};
use zer_schema::{
    artifact::ModelArtifact,
    fingerprint::SchemaFingerprint,
    registry::{SchemaRegistry, StartupMode},
};

const BRP_Q1_CSV: &str = concat!(
    env!("CARGO_MANIFEST_DIR"),
    "/../../data/examples/brp_q1/brp_persons.csv"
);

const BRP_Q2_CSV: &str = concat!(
    env!("CARGO_MANIFEST_DIR"),
    "/../../data/examples/brp_q2/brp_persons.csv"
);

fn load_records(path: &str) -> Vec<Record> {
    let mut rdr = csv::Reader::from_path(path)
        .unwrap_or_else(|_| panic!("CSV not found: {path}"));
    let headers = rdr.headers().unwrap().clone();
    let mut records = Vec::new();
    let mut id: u64 = 1;
    for result in rdr.records() {
        let row = result.unwrap();
        let mut r = Record::new(id);
        for (i, header) in headers.iter().enumerate() {
            let v = row.get(i).unwrap_or("").trim();
            r = r.insert(
                header,
                if v.is_empty() { FieldValue::Null } else { FieldValue::Text(v.into()) },
            );
        }
        records.push(r);
        id += 1;
    }
    records
}

fn brp_schema_base() -> zer_core::schema::Schema {
    SchemaBuilder::new()
        .field("bsn",            FieldKind::Id)
        .field("voornamen",      FieldKind::Name)
        .field("tussenvoegsel",  FieldKind::Categorical)
        .field("achternaam",     FieldKind::Name)
        .field("geboortedatum",  FieldKind::Date)
        .field("geboorteplaats", FieldKind::Categorical)
        .field("geboorteland",   FieldKind::Categorical)
        .field("nationaliteit",  FieldKind::Categorical)
        .field("geslacht",       FieldKind::Categorical)
        .field("straatnaam",     FieldKind::Address)
        .field("huisnummer",     FieldKind::Address)
        .field("postcode",       FieldKind::Id)
        .field("woonplaats",     FieldKind::Address)
        .build()
        .unwrap()
}

fn brp_schema_extended() -> zer_core::schema::Schema {
    SchemaBuilder::new()
        .field("bsn",             FieldKind::Id)
        .field("voornamen",       FieldKind::Name)
        .field("tussenvoegsel",   FieldKind::Categorical)
        .field("achternaam",      FieldKind::Name)
        .field("geboortedatum",   FieldKind::Date)
        .field("geboorteplaats",  FieldKind::Categorical)
        .field("geboorteland",    FieldKind::Categorical)
        .field("nationaliteit",   FieldKind::Categorical)
        .field("geslacht",        FieldKind::Categorical)
        .field("straatnaam",      FieldKind::Address)
        .field("huisnummer",      FieldKind::Address)
        .field("postcode",        FieldKind::Id)
        .field("woonplaats",      FieldKind::Address)
        .field("verblijfstitel",  FieldKind::Categorical) // added field
        .build()
        .unwrap()
}

fn sim_schema() -> zer_core::schema::Schema {
    SchemaBuilder::new()
        .field("sim_id",          FieldKind::Id)
        .field("msisdn",          FieldKind::Phone)
        .field("imsi",            FieldKind::Id)
        .field("iccid",           FieldKind::Id)
        .field("carrier",         FieldKind::Categorical)
        .field("contract_type",   FieldKind::Categorical)
        .field("activatiedatum",  FieldKind::Date)
        .field("voornamen",       FieldKind::Name)
        .field("achternaam",      FieldKind::Name)
        .field("geboortedatum",   FieldKind::Date)
        .field("nationaliteit",   FieldKind::Categorical)
        .field("document_type",   FieldKind::Categorical)
        .field("document_nummer", FieldKind::Id)
        .field("bsn",             FieldKind::Id)
        .build()
        .unwrap()
}

/// Simulate EM training by building dummy params (in real code you'd call
/// `FellegiSunterScorer::estimate_params`).
fn simulate_em(n_fields: usize) -> (ModelParams, usize) {
    let params = ModelParams {
        m: vec![vec![0.02, 0.06, 0.12, 0.80]; n_fields],
        u: vec![vec![0.70, 0.15, 0.10, 0.05]; n_fields],
        log_prior_odds: -2.0,
        upper_threshold: 0.9,
        lower_threshold: 0.1,
    };
    (params, 25)
}

fn main() {
    println!("=== zer-schema: registry warm-start example ===\n");

    // ── Setup: open a temporary registry ─────────────────────────────────────

    let dir = tempfile::tempdir().expect("failed to create temp dir");
    let registry = SchemaRegistry::open(&dir.path().join("demo.zsm")).expect("failed to open registry");

    // ── Step 1: Train on BRP Q1 and save artifact ─────────────────────────────

    println!("Step 1, Training on BRP Q1 ...");
    let q1_records = load_records(BRP_Q1_CSV);
    let base_schema = brp_schema_base();
    let fp_q1 = SchemaFingerprint::from_sample(&base_schema, &q1_records);

    let (params, iterations) = simulate_em(base_schema.len());
    let artifact = ModelArtifact {
        fingerprint: fp_q1.clone(),
        params,
        tag: Some("brp_q1_2024".into()),
        trained_on: 0,
        em_iterations: iterations,
    };
    registry.save(&artifact).expect("save must succeed");
    println!("  Saved artifact 'brp_q1_2024' ({} fields, {} EM iterations).", base_schema.len(), iterations);

    // Check serialized size
    let bytes = artifact.to_bytes().unwrap();
    println!("  Serialized size: {} bytes ({:.1} KB).", bytes.len(), bytes.len() as f64 / 1024.0);
    assert!(bytes.len() < 10_240, "artifact should be under 10 KB");

    // ── Step 2: Arrive with BRP Q2, same schema ──────────────────────────────

    println!("\nStep 2, Arriving with BRP Q2 (same schema) ...");
    let q2_records = load_records(BRP_Q2_CSV);
    let fp_q2 = SchemaFingerprint::from_sample(&base_schema, &q2_records);

    match registry.lookup_startup_mode(&fp_q2).expect("lookup failed") {
        StartupMode::WarmLoad(art) => {
            println!("  → WarmLoad: loaded '{}', EM skipped entirely. ✓",
                art.tag.as_deref().unwrap_or("(no tag)"));
        }
        other => panic!("expected WarmLoad, got {:?}", std::mem::discriminant(&other)),
    }

    // ── Step 3: Arrive with extended schema (verblijfstitel added) ────────────

    println!("\nStep 3, Arriving with extended BRP schema (verblijfstitel added) ...");
    let fp_ext = SchemaFingerprint::from_schema(&brp_schema_extended());

    match registry.lookup_startup_mode(&fp_ext).expect("lookup failed") {
        StartupMode::WarmStart { artifact: art, distance: d } => {
            println!("  → WarmStart: loaded '{}', distance={:.4}, run 2–3 EM iterations. ✓",
                art.tag.as_deref().unwrap_or("(no tag)"), d);
        }
        other => panic!("expected WarmStart, got {:?}", std::mem::discriminant(&other)),
    }

    // ── Step 4: Arrive with SIM subscriber schema ─────────────────────────────

    println!("\nStep 4, Arriving with SIM subscriber schema (incompatible) ...");
    let fp_sim = SchemaFingerprint::from_schema(&sim_schema());

    match registry.lookup_startup_mode(&fp_sim).expect("lookup failed") {
        StartupMode::ColdStart => {
            println!("  → ColdStart: no suitable prior found, run full EM. ✓");
        }
        other => panic!("expected ColdStart, got {:?}", std::mem::discriminant(&other)),
    }

    // ── Step 5: list_all and delete ───────────────────────────────────────────

    println!("\nStep 5, Inspecting and cleaning registry ...");
    let all = registry.list_all().expect("list_all failed");
    println!("  Registry contains {} artifact(s):", all.len());
    for a in &all {
        println!("    • {} (trained_on={})", a.tag.as_deref().unwrap_or("(no tag)"), a.trained_on);
    }

    let removed = registry.delete(&artifact.fingerprint.schema_hash).expect("delete failed");
    assert!(removed, "delete must return true for existing artifact");
    println!("  Deleted 'brp_q1_2024'. Registry now empty: {}", registry.list_all().unwrap().is_empty());

    println!("\nExample completed successfully.");
}