//! Consume the published `aac` conformance pack.
//!
//! `gen_vectors` writes `aac/conformance/v1/cascade.json` and nothing read it back,
//! so the published cascade — the table a third-party implementation certifies
//! against — was never checked against the engine that produces it.
//!
//! The pack also **declares its own invariants**, and that block is written as
//! literals by the generator rather than derived from the levels beside it:
//!
//! ```text
//! "invariants": { "energy_strictly_monotonic": true, "offline_levels": ["L0","L1","L2"] }
//! ```
//!
//! So the pack asserts those properties; nothing made them true. If `is_offline()`
//! moved a level, the generator would emit the new `levels` array next to the old
//! claim and the file would contradict itself. These tests check the declared
//! invariants against the published data, which is what turns the claim into a fact.

use aac_core::{AacCascade, AacCascadeLevel, AacOperation};
use serde_json::Value;
use std::path::PathBuf;

/// The level order and tags the generator publishes.
const LEVELS: [(AacCascadeLevel, &str); 10] = [
    (AacCascadeLevel::CacheHit, "L0"),
    (AacCascadeLevel::SymbolLookup, "L1"),
    (AacCascadeLevel::LocalPredict, "L2"),
    (AacCascadeLevel::ContextPredict, "L3"),
    (AacCascadeLevel::SemanticExpand, "L4"),
    (AacCascadeLevel::ConversationAi, "L5"),
    (AacCascadeLevel::GenerativeComm, "L6"),
    (AacCascadeLevel::VoiceClone, "L7"),
    (AacCascadeLevel::MultimodalGen, "L8"),
    (AacCascadeLevel::AdaptiveModel, "L9"),
];

const OPS: [(AacOperation, &str); 10] = [
    (AacOperation::CellSelect, "CellSelect"),
    (AacOperation::SymbolSearch, "SymbolSearch"),
    (AacOperation::WordPrediction, "WordPrediction"),
    (AacOperation::SocialScript, "SocialScript"),
    (AacOperation::SentenceConstruction, "SentenceConstruction"),
    (AacOperation::ConversationRepair, "ConversationRepair"),
    (AacOperation::ComposeLong, "ComposeLong"),
    (AacOperation::VoiceBanking, "VoiceBanking"),
    (AacOperation::SymbolGeneration, "SymbolGeneration"),
    (AacOperation::ModelRetrain, "ModelRetrain"),
];

fn pack() -> Value {
    let p = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("../../../conformance/v1/cascade.json")
        .canonicalize()
        .expect("the conformance pack must exist next to the spec");
    serde_json::from_slice(&std::fs::read(&p).expect("read cascade.json"))
        .expect("cascade.json must parse")
}

fn levels(doc: &Value) -> &Vec<Value> {
    doc["levels"].as_array().expect("the pack publishes a level table")
}

/// The engine still produces exactly the published cascade.
///
/// Rebuilt in process rather than by running the generator: `gen_vectors` writes to
/// a hardcoded relative path with no output argument, so running it to diff would
/// overwrite the published file.
#[test]
fn the_engine_still_produces_the_published_cascade() {
    let doc = pack();
    assert_eq!(doc["standard"], "aac");
    assert_eq!(doc["vector"], "cascade");

    let rebuilt_levels: Vec<Value> = LEVELS
        .iter()
        .enumerate()
        .map(|(i, (lvl, tag))| {
            serde_json::json!({
                "index": i,
                "tag": tag,
                "name": lvl.label(),
                "energy_uj": lvl.estimated_energy_uj(),
                "offline": lvl.is_offline(),
            })
        })
        .collect();
    assert_eq!(&rebuilt_levels, levels(&doc), "the level table has drifted from the engine");

    let rebuilt_routes: Vec<Value> = OPS
        .iter()
        .map(|(op, name)| {
            let lvl = AacCascade::level_for_operation(*op);
            let tag = LEVELS.iter().find(|(l, _)| l == &lvl).map(|(_, t)| *t).expect("known level");
            serde_json::json!({ "operation": name, "level": tag })
        })
        .collect();
    assert_eq!(&rebuilt_routes, doc["routing"].as_array().unwrap(), "routing has drifted");
}

/// The invariants the pack declares, checked against the data it ships beside them.
///
/// Both are literals in the generator. Until something compares them to the levels,
/// a pack that contradicts itself would publish cleanly.
#[test]
fn the_declared_invariants_hold_over_the_published_levels() {
    let doc = pack();
    let inv = &doc["invariants"];
    let levels = levels(&doc);
    assert_eq!(levels.len(), 10, "a truncated table must not look like a pass");

    // Indices and tags are consistent and contiguous.
    for (i, l) in levels.iter().enumerate() {
        assert_eq!(l["index"].as_u64().unwrap() as usize, i, "level {i} index disagrees");
        assert_eq!(l["tag"].as_str().unwrap(), format!("L{i}"), "level {i} tag disagrees");
    }

    if inv["energy_strictly_monotonic"].as_bool().expect("declared monotonicity") {
        for w in levels.windows(2) {
            let (a, b) = (w[0]["energy_uj"].as_u64().unwrap(), w[1]["energy_uj"].as_u64().unwrap());
            assert!(
                b > a,
                "the pack declares strictly monotonic energy but {} ({a} uJ) is not below {} ({b} uJ)",
                w[0]["tag"],
                w[1]["tag"]
            );
        }
    }

    let declared: Vec<&str> = inv["offline_levels"]
        .as_array()
        .expect("declared offline levels")
        .iter()
        .map(|v| v.as_str().unwrap())
        .collect();
    let actual: Vec<&str> = levels
        .iter()
        .filter(|l| l["offline"].as_bool().unwrap())
        .map(|l| l["tag"].as_str().unwrap())
        .collect();
    assert_eq!(
        actual, declared,
        "the levels marked offline do not match the offline_levels the pack declares"
    );
}

/// The accessibility property the cascade exists to protect: the operations a person
/// needs to say something at all must route to a level that works offline.
///
/// Selecting a cell, searching for a symbol and predicting a word are how an AAC user
/// forms basic utterances. If any of those routed above the offline boundary, losing
/// connectivity would cost someone their voice, not merely a feature.
#[test]
fn basic_communication_routes_below_the_offline_boundary() {
    let doc = pack();
    let offline: Vec<&str> = levels(&doc)
        .iter()
        .filter(|l| l["offline"].as_bool().unwrap())
        .map(|l| l["tag"].as_str().unwrap())
        .collect();

    let route_of = |op: &str| -> String {
        doc["routing"]
            .as_array()
            .unwrap()
            .iter()
            .find(|r| r["operation"] == op)
            .unwrap_or_else(|| panic!("the pack routes {op}"))["level"]
            .as_str()
            .unwrap()
            .to_string()
    };

    for op in ["CellSelect", "SymbolSearch", "WordPrediction"] {
        let lvl = route_of(op);
        assert!(
            offline.contains(&lvl.as_str()),
            "{op} routes to {lvl}, which the pack marks online — basic communication \
             must not depend on connectivity"
        );
    }

    // And the converse, so the offline set is not trivially everything: the expensive
    // generative operations are online, which is why they are allowed to cost more.
    for op in ["ComposeLong", "VoiceBanking", "ModelRetrain"] {
        let lvl = route_of(op);
        assert!(!offline.contains(&lvl.as_str()), "{op} unexpectedly routes offline ({lvl})");
    }
}

/// Every published operation routes to a level the pack also publishes, and every
/// level is reachable — a routing table naming a level that does not exist, or a
/// level nothing can reach, is a table nobody can implement against.
#[test]
fn routing_and_levels_are_mutually_complete() {
    let doc = pack();
    let tags: Vec<&str> = levels(&doc).iter().map(|l| l["tag"].as_str().unwrap()).collect();
    let routes = doc["routing"].as_array().expect("the pack publishes routing");
    assert_eq!(routes.len(), OPS.len(), "routing must cover every operation");

    for r in routes {
        let lvl = r["level"].as_str().unwrap();
        assert!(tags.contains(&lvl), "{} routes to unknown level {lvl}", r["operation"]);
    }
    for tag in &tags {
        assert!(
            routes.iter().any(|r| r["level"] == *tag),
            "level {tag} is published but no operation reaches it"
        );
    }
}