//! The published pack, `smart-byte/conformance/v1`, held to the reference
//! implementation under `cargo test` — so CI fails whenever the two disagree.

use std::collections::BTreeSet;
use std::path::Path;

use serde_json::{Value, json};
use smart_byte_conformance::verify::{readme_error_classes, spec_cited_said_vectors};
use smart_byte_conformance::{pack, published_pack_dir, verify::verify_pack};

fn published(file: &str) -> String {
    std::fs::read_to_string(published_pack_dir().join(file))
        .unwrap_or_else(|e| panic!("read {file}: {e}"))
}

fn vectors(file: &str) -> Vec<Value> {
    serde_json::from_str::<Value>(&published(file))
        .unwrap()
        .as_array()
        .unwrap()
        .clone()
}

fn by_name(file: &str, name: &str) -> Value {
    vectors(file)
        .into_iter()
        .find(|v| v["name"] == name)
        .unwrap_or_else(|| panic!("{file} has no vector {name}"))
}

#[test]
fn every_published_vector_agrees_with_the_reference() {
    let report = verify_pack(&published_pack_dir());
    let failures = report.failures();
    assert!(failures.is_empty(), "{failures:#?}");
    // One structure check per file, one check per vector, two completeness
    // checks: none skipped.
    let total: usize = pack::FILES.iter().map(|f| vectors(f).len()).sum();
    assert_eq!(report.checks.len(), pack::FILES.len() + total + 2);
}

#[test]
fn the_published_pack_is_exactly_what_the_reference_generates() {
    for (file, generated) in pack::generate() {
        assert!(
            published(file) == generated,
            "{file} differs from the reference implementation's output; regenerate with \
             `cargo run -p smart-byte-conformance --bin gen-conformance-vectors`"
        );
    }
}

/// Write the published pack to `dir` with `edit` applied to the files'
/// parsed contents, and return the names of the checks the verifier fails.
fn failures_with(dir: &Path, edit: impl Fn(&str, &mut Vec<Value>)) -> Vec<String> {
    std::fs::create_dir_all(dir).unwrap();
    for f in pack::FILES {
        let mut items = vectors(f);
        edit(f, &mut items);
        std::fs::write(dir.join(f), serde_json::to_string_pretty(&items).unwrap()).unwrap();
    }
    verify_pack(dir)
        .failures()
        .into_iter()
        .map(|c| c.vector.clone())
        .collect()
}

fn scratch(name: &str) -> std::path::PathBuf {
    Path::new(env!("CARGO_TARGET_TMPDIR")).join(name)
}

/// Falsification: the verifier is not vacuous. Each planted defect — a wrong
/// value, a wrong error class, a negative vector turned positive — must be
/// caught, and caught on the vector it was planted in.
#[test]
fn the_verifier_catches_a_planted_defect_in_every_file() {
    let flip_last = |s: &str| {
        let mut s = s.to_owned();
        let last = s.pop().unwrap();
        s.push(if last == '0' { '1' } else { '0' });
        s
    };
    type Plant = (&'static str, &'static str, Box<dyn Fn(&mut Value)>);
    let plants: Vec<Plant> = vec![
        (
            "canonicalisation_vectors.json",
            "canon-001-sorted-map-keys",
            Box::new(move |v| {
                v["expected_cbor_hex"] = json!(flip_last(v["expected_cbor_hex"].as_str().unwrap()))
            }),
        ),
        (
            "canonicalisation_vectors.json",
            "canon-012-text-ordered-keys-refused",
            Box::new(|v| v["error"] = json!("duplicate_map_key")),
        ),
        (
            "canonicalisation_vectors.json",
            "canon-004-floats-forbidden",
            Box::new(|v| v["input_cbor_hex"] = json!("a16a65786163745f68616c6601")),
        ),
        (
            "canonicalisation_vectors.json",
            "canon-020-simple-value-refused",
            Box::new(|v| v["input_cbor_hex"] = json!("f6")),
        ),
        (
            "said_vectors.json",
            "said-008-spec-worked-example",
            Box::new(move |v| {
                v["expected_said"] = json!(flip_last(v["expected_said"].as_str().unwrap()))
            }),
        ),
        (
            "said_vectors.json",
            "said-009-non-canonical-copy-rejected",
            Box::new(|v| v["error"] = json!("said_mismatch")),
        ),
        (
            "said_vectors.json",
            "said-010-self-consistent-non-canonical-rejected",
            Box::new(move |v| {
                v["said_of_received_bytes"] =
                    json!(flip_last(v["said_of_received_bytes"].as_str().unwrap()))
            }),
        ),
        (
            "said_vectors.json",
            "said-003-transferred-envelope",
            Box::new(|v| v["input"]["joule_cost"]["measured_microjoules"] = json!(1201)),
        ),
        (
            "signature_vectors.json",
            "sig-001-issuer-attestation",
            Box::new(move |v| v["signature"] = json!(flip_last(v["signature"].as_str().unwrap()))),
        ),
        (
            "signature_vectors.json",
            "sig-003-message-swapped",
            Box::new(|v| {
                v["expected_verify"] = json!(true);
                v["error"] = Value::Null;
            }),
        ),
        (
            "signature_vectors.json",
            "sig-006-non-canonical-s-rejected",
            Box::new(|v| v["error"] = json!("malformed_signature")),
        ),
        (
            "signature_vectors.json",
            "sig-007-non-canonical-key-rejected",
            // The canonical spelling of the same point: now a well-formed key
            // that merely fails to verify, so the published class is wrong.
            Box::new(|v| {
                v["verifying_key"] =
                    json!("0300000000000000000000000000000000000000000000000000000000000000")
            }),
        ),
        (
            "kel_vectors.json",
            "kel-004-no-next-keys",
            Box::new(|v| v["expected"]["next_threshold"] = json!(1)),
        ),
        (
            "kel_vectors.json",
            "kel-008-rotation-signed-by-current-keys",
            Box::new(|v| v["error"] = json!("pre_rotation_mismatch")),
        ),
        (
            "kel_vectors.json",
            "kel-017-rotation-after-no-next-keys",
            Box::new(|v| v["error_at"] = json!(0)),
        ),
        (
            "kel_vectors.json",
            "kel-022-key-written-as-integers",
            // The issuer's inception in its own encoding, with its own
            // signature: a log the vector says must be refused, accepted.
            Box::new(|v| {
                v["events"] =
                    by_name("kel_vectors.json", "kel-001-single-key-inception")["events"].clone()
            }),
        ),
        (
            "kel_vectors.json",
            "kel-013-duplicate-key",
            // A seed that did not make the signature beside it.
            Box::new(|v| v["events"][0]["signatures"][1]["seed"] = json!("00".repeat(32))),
        ),
        (
            "envelope_vectors.json",
            "env-001-issued",
            Box::new(move |v| {
                v["expected"]["history_hash"] =
                    json!(flip_last(v["expected"]["history_hash"].as_str().unwrap()))
            }),
        ),
        (
            "envelope_vectors.json",
            "env-011-old-key-under-new-establishment",
            Box::new(|v| v["error"] = json!("below_threshold")),
        ),
        (
            "envelope_vectors.json",
            "env-018-cargo-bytes-written-as-integers",
            // env-003 in its own encoding: accepted, though the vector says
            // it must be refused.
            Box::new(|v| {
                let own = by_name("envelope_vectors.json", "env-003-empty-opaque-cargo");
                v["envelope"] = own["envelope"].clone();
                v["cbor_hex"] = own["cbor_hex"].clone();
            }),
        ),
        (
            "envelope_vectors.json",
            "env-002-transfers-across-a-rotation",
            Box::new(|v| v["expected"]["owner"] = v["expected"]["issuer"].clone()),
        ),
        (
            "state_vectors.json",
            "state-001-issue-transfer-rotate",
            Box::new(move |v| {
                let h = v["frames"][1]["expected_state_hash"]
                    .as_str()
                    .unwrap()
                    .to_owned();
                v["frames"][1]["expected_state_hash"] = json!(flip_last(&h));
            }),
        ),
        (
            "state_vectors.json",
            "state-007-transfer-checks",
            Box::new(|v| {
                let results = v["frames"][1]["expected_results"].as_array_mut().unwrap();
                let r = results
                    .iter_mut()
                    .find(|r| r["error"] == "broken_history_chain")
                    .unwrap();
                r["error"] = json!("unknown_byte");
            }),
        ),
        (
            "state_vectors.json",
            "state-004-rotation-retires-old-keys",
            // Application order is part of the result: the key event first.
            Box::new(|v| {
                v["frames"][1]["expected_results"]
                    .as_array_mut()
                    .unwrap()
                    .reverse()
            }),
        ),
        (
            "state_vectors.json",
            "state-011-malformed-inputs",
            Box::new(|v| {
                let results = v["frames"][0]["expected_results"].as_array_mut().unwrap();
                let r = results
                    .iter_mut()
                    .find(|r| r["error"] == "non_shortest_integer")
                    .unwrap();
                r["class"] = json!("transfer");
            }),
        ),
        (
            "state_vectors.json",
            "state-012-duplicate-submissions",
            // A duplicate counted as a second input.
            Box::new(|v| {
                let results = v["frames"][0]["expected_results"].as_array_mut().unwrap();
                let first = results[0].clone();
                results.insert(1, first);
            }),
        ),
        (
            "state_vectors.json",
            "state-009-signers-need-their-log",
            // Without Alice's inception her transfer cannot be checked.
            Box::new(|v| {
                let inputs = v["frames"][2]["inputs"].as_array_mut().unwrap();
                inputs.retain(|i| i["input"].get("key_event").is_none());
            }),
        ),
        (
            "state_vectors.json",
            "state-013-issuer-added-after-the-delay",
            Box::new(|v| v["frames"][2]["expected_results"][0]["error"] = json!("below_quorum")),
        ),
        (
            "state_vectors.json",
            "state-015-removal-without-the-target",
            Box::new(|v| v["frames"][1]["expected_results"][0]["error"] = json!("below_quorum")),
        ),
        (
            "state_vectors.json",
            "state-018-redemption",
            Box::new(|v| {
                let results = v["frames"][3]["expected_results"].as_array_mut().unwrap();
                let r = results
                    .iter_mut()
                    .find(|r| r["error"] == "duplicate_byte")
                    .unwrap();
                r["error"] = json!("byte_retired");
            }),
        ),
        (
            "state_vectors.json",
            "state-019-export-and-return",
            Box::new(move |v| {
                let h = v["frames"][2]["expected_state_hash"]
                    .as_str()
                    .unwrap()
                    .to_owned();
                v["frames"][2]["expected_state_hash"] = json!(flip_last(&h));
            }),
        ),
        (
            "state_vectors.json",
            "state-020-import-and-send-back",
            Box::new(|v| {
                let results = v["frames"][0]["expected_results"].as_array_mut().unwrap();
                let r = results.iter_mut().find(|r| r["class"] == "import").unwrap();
                r["outcome"] = json!("dropped");
                r["error"] = json!("duplicate_import");
            }),
        ),
        (
            "state_vectors.json",
            "state-021-import-checks",
            Box::new(|v| {
                let results = v["frames"][1]["expected_results"].as_array_mut().unwrap();
                let r = results
                    .iter_mut()
                    .find(|r| r["error"] == "below_threshold")
                    .unwrap();
                r["error"] = json!("signature_invalid");
            }),
        ),
        (
            "state_vectors.json",
            "state-023-an-import-meets-the-byte",
            // A burned byte's import reported as if the byte were still live.
            Box::new(|v| v["frames"][2]["expected_results"][0]["error"] = json!("duplicate_byte")),
        ),
        (
            "lockstep_vectors.json",
            "lockstep-002-supermajority-commit",
            Box::new(|v| v["expected_dissent_logs"]["node_1"] = json!([])),
        ),
        (
            "lockstep_vectors.json",
            "lockstep-004-three-nodes-one-diverged-split",
            Box::new(|v| v["expected_commit"] = json!(true)),
        ),
        (
            "lockstep_vectors.json",
            "lockstep-002-supermajority-commit",
            Box::new(|v| v["expected_outcomes"]["node_4"] = json!("commit_with_dissent")),
        ),
        (
            "lockstep_vectors.json",
            "lockstep-006-transport-liar-is-logged",
            Box::new(|v| v["expected_outcomes"]["node_4"] = json!("minority_divergence")),
        ),
        (
            "gossip_vectors.json",
            "gossip-002-said-conflict-rejected",
            Box::new(|v| {
                v["expected_results"][1] =
                    json!({"outcome": "duplicate", "said": v["expected_results"][0]["said"]})
            }),
        ),
        (
            "gossip_vectors.json",
            "gossip-005-non-canonical-copy-rejected",
            Box::new(|v| {
                let s = v["deliveries"][0]["claimed_said"].clone();
                let b = v["deliveries"][0]["cbor_hex"].clone();
                v["expected_results"][0] = json!({"outcome": "accepted", "said": s});
                v["expected_held"] = json!([{"said": s, "cbor_hex": b}]);
            }),
        ),
        (
            "gossip_vectors.json",
            "gossip-001-cross-node-propagation",
            Box::new(move |v| {
                let h = v["expected_held"][0]["cbor_hex"]
                    .as_str()
                    .unwrap()
                    .to_owned();
                v["expected_held"][0]["cbor_hex"] = json!(flip_last(&h));
            }),
        ),
    ];
    for (i, (file, name, mutate)) in plants.iter().enumerate() {
        let failed = failures_with(&scratch(&format!("planted/{i}")), |f, items| {
            if f == *file {
                mutate(items.iter_mut().find(|v| v["name"] == *name).expect(name));
            }
        });
        assert_eq!(
            failed,
            vec![name.to_string()],
            "planted defect {i} in {file}/{name}"
        );
    }
}

/// A defect in a log the envelope vectors draw key states from fails that
/// log and every envelope vector, and nothing else.
#[test]
fn a_defect_in_a_log_fails_the_envelopes_that_rely_on_it() {
    let failed = failures_with(&scratch("planted/log-dependency"), |f, items| {
        if f == "kel_vectors.json" {
            let v = items
                .iter_mut()
                .find(|v| v["name"] == "kel-003-two-of-three-rotation")
                .unwrap();
            // Drop the rotation's second signature: one of the two it needs.
            v["events"][1]["signatures"].as_array_mut().unwrap().pop();
        }
    });
    let mut expected = vec!["kel-003-two-of-three-rotation".to_string()];
    expected.extend(
        vectors("envelope_vectors.json")
            .iter()
            .map(|v| v["name"].as_str().unwrap().to_owned()),
    );
    assert_eq!(failed, expected);
}

/// Falsification: a pack cannot pass by losing vectors.
#[test]
fn an_incomplete_pack_fails() {
    // Every file emptied.
    let failed = failures_with(&scratch("incomplete/empty"), |_, items| items.clear());
    for f in pack::FILES {
        assert!(failed.contains(&"(file)".to_string()), "{f}");
    }
    assert!(failed.contains(&"spec-cited vectors present".to_string()));
    assert!(failed.contains(&"README error classes exercised".to_string()));

    // One vector the spec cites, deleted.
    let failed = failures_with(&scratch("incomplete/said-010"), |f, items| {
        if f == "said_vectors.json" {
            items.retain(|v| !v["name"].as_str().unwrap().starts_with("said-010-"));
        }
    });
    assert_eq!(failed, vec!["spec-cited vectors present".to_string()]);

    // The only vector exercising a README error class, deleted.
    let failed = failures_with(&scratch("incomplete/class"), |f, items| {
        if f == "canonicalisation_vectors.json" {
            items.retain(|v| v["name"] != "canon-020-simple-value-refused");
        }
    });
    assert_eq!(failed, vec!["README error classes exercised".to_string()]);
}

/// Falsification: a vector that names an error class the README does not
/// list is caught, so the README stays the full list.
#[test]
fn an_undocumented_error_class_fails() {
    let failed = failures_with(&scratch("undocumented"), |f, items| {
        if f == "canonicalisation_vectors.json" {
            let mut extra = items
                .iter()
                .find(|v| v["name"] == "canon-018-trailing-bytes-refused")
                .unwrap()
                .clone();
            extra["name"] = json!("canon-099-made-up");
            extra["error"] = json!("made_up_class");
            items.push(extra);
        }
    });
    assert!(failed.contains(&"README error classes exercised".to_string()));
    assert!(failed.contains(&"canon-099-made-up".to_string()));
}

#[test]
fn a_pack_with_a_duplicated_json_member_fails() {
    let dir = scratch("duplicate-member");
    std::fs::create_dir_all(&dir).unwrap();
    for f in pack::FILES {
        let mut body = published(f);
        if f == "lockstep_vectors.json" {
            // Name a member twice; a plain JSON parser would keep the last.
            body = body.replacen(
                "\"node_count\": 4,",
                "\"node_count\": 4,\n    \"node_count\": 4,",
                1,
            );
        }
        std::fs::write(dir.join(f), body).unwrap();
    }
    let report = verify_pack(&dir);
    let failed: Vec<&str> = report.failures().iter().map(|c| c.file.as_str()).collect();
    assert_eq!(failed, vec!["lockstep_vectors.json"]);
}

#[test]
fn the_said_pack_holds_the_suite_the_spec_names() {
    let cited = spec_cited_said_vectors().unwrap();
    for n in 1..=11 {
        assert!(
            cited.contains(&format!("said-{n:03}")),
            "the spec no longer cites said-{n:03}"
        );
    }
    let keys = |name: &str| -> BTreeSet<String> {
        by_name("said_vectors.json", name)["input"]
            .as_object()
            .unwrap()
            .keys()
            .cloned()
            .collect()
    };
    let set = |ks: &[&str]| ks.iter().map(|k| k.to_string()).collect::<BTreeSet<_>>();
    assert_eq!(keys("said-006-only-said-field"), set(&["d"]));
    assert_eq!(keys("said-007-one-field-per-key"), set(&["d", "k"]));
    assert_eq!(keys("said-008-spec-worked-example"), set(&["d", "n"]));
}

#[test]
fn every_canonical_rule_has_a_negative_vector() {
    let classes: BTreeSet<String> = vectors("canonicalisation_vectors.json")
        .into_iter()
        .filter_map(|v| v["error"].as_str().map(str::to_owned))
        .collect();
    for rule in [
        "non_shortest_integer",
        "non_shortest_length",
        "unsorted_map_keys",
        "duplicate_map_key",
        "float_forbidden",
        "simple_value_forbidden",
        "tag_forbidden",
        "indefinite_length",
        "invalid_utf8",
        "trailing_bytes",
    ] {
        assert!(
            classes.contains(rule),
            "no canonicalisation vector is refused with {rule}"
        );
        assert!(
            readme_error_classes().unwrap().contains(rule),
            "README omits {rule}"
        );
    }
}

#[test]
fn the_spec_prints_the_worked_example_the_pack_computes() {
    let spec = std::fs::read_to_string(
        Path::new(env!("CARGO_MANIFEST_DIR")).join("../../../spec/identity_and_key_rotation.md"),
    )
    .unwrap();
    let example = by_name("said_vectors.json", "said-008-spec-worked-example");
    for field in ["blake3_hex", "expected_said", "canonical_cbor_hex"] {
        let value = example[field].as_str().unwrap();
        assert!(
            spec.contains(value),
            "identity spec §2.4 does not print the pack's {field} {value}"
        );
    }
    assert!(
        spec.contains("total 61 bytes"),
        "§2.4 must give the encoding's real length"
    );
}

/// The files describe one world: the SAID vectors' objects are the envelope
/// and key-event-log vectors' objects, and the signature vectors sign their
/// messages.
#[test]
fn the_files_describe_one_world() {
    let said = |name: &str| by_name("said_vectors.json", name)["expected_said"].clone();
    let issued = by_name("envelope_vectors.json", "env-001-issued");
    let transferred = by_name(
        "envelope_vectors.json",
        "env-002-transfers-across-a-rotation",
    );
    let alice = by_name("kel_vectors.json", "kel-002-rotation-then-interaction");
    assert_eq!(
        said("said-001-issued-envelope"),
        issued["expected"]["snapshot"]
    );
    assert_eq!(
        said("said-002-byte-identity"),
        issued["expected"]["identity"]
    );
    assert_eq!(
        said("said-003-transferred-envelope"),
        transferred["expected"]["snapshot"]
    );
    assert_eq!(
        said("said-004-rotation-event"),
        alice["expected"]["event_saids"][1]
    );
    assert_eq!(
        said("said-005-interaction-event"),
        alice["expected"]["event_saids"][2]
    );
    // Alice's interaction anchors the byte she was issued.
    assert_eq!(
        alice["events"][2]["event"]["a"][0],
        issued["expected"]["identity"]
    );

    let sig = |name: &str| by_name("signature_vectors.json", name);
    let without_algorithm = |j: &Value| j.as_str().unwrap()[2..].to_owned();
    let attestation = smart_byte_conformance::world::World::build()
        .issued
        .provenance
        .signed_bytes();
    assert_eq!(
        sig("sig-001-issuer-attestation")["message_hex"],
        json!(hex::encode(attestation))
    );
    assert_eq!(
        sig("sig-001-issuer-attestation")["signature"],
        json!(without_algorithm(
            &issued["envelope"]["provenance"]["signature"]["signatures"][0]["signature"]["$bytes"]
        ))
    );
    assert_eq!(
        sig("sig-002-key-event")["message_hex"],
        alice["events"][0]["cbor_hex"]
    );
    assert_eq!(
        sig("sig-002-key-event")["signature"],
        json!(without_algorithm(
            &alice["events"][0]["signatures"][0]["signature"]
        ))
    );

    // The cluster's founding frame: the three logs' inceptions and env-001's
    // mint, as the other files give them.
    let journey = by_name("state_vectors.json", "state-001-issue-transfer-rotate");
    let founding: Vec<&Value> = journey["frames"][0]["inputs"]
        .as_array()
        .unwrap()
        .iter()
        .map(|i| &i["input"])
        .collect();
    for log in [
        "kel-001-single-key-inception",
        "kel-002-rotation-then-interaction",
        "kel-003-two-of-three-rotation",
    ] {
        let event = &by_name("kel_vectors.json", log)["events"][0]["event"];
        assert!(
            founding.iter().any(|i| &i["key_event"]["event"] == event),
            "{log}'s inception"
        );
    }
    assert!(
        founding
            .iter()
            .any(|i| i["mint"] == issued["envelope"]["provenance"]),
        "env-001's mint"
    );
    // A's export is what B imports, and B's export is what A takes back.
    let a = by_name("state_vectors.json", "state-019-export-and-return");
    let b = by_name("state_vectors.json", "state-020-import-and-send-back");
    let id = issued["expected"]["identity"].as_str().unwrap();
    let imported = |frame: &Value| {
        frame["inputs"]
            .as_array()
            .unwrap()
            .iter()
            .find_map(|i| i["input"].get("import").cloned())
            .unwrap()["certificate"]["statement"]["export"]
            .clone()
    };
    assert_eq!(
        imported(&b["frames"][0]),
        a["frames"][2]["expected_state"]["exported"][id]
    );
    assert_eq!(
        imported(&a["frames"][4]),
        b["frames"][1]["expected_state"]["exported"][id]
    );
    // The byte the cluster holds is env-001's.
    let state = &journey["frames"][0]["expected_state"];
    assert!(
        state["bytes"]
            .get(issued["expected"]["identity"].as_str().unwrap())
            .is_some()
    );
}