use indexmap::IndexMap;

struct Lookup {
    generated: Map<Id, i64>,
    reference: IndexMap<Id, i64>,
    keys: Vec<Id>,
}

struct Comparison {
    values: Vec<Id>,
    expected: Id,
}

fn id_fault() -> Fault {
    &FaultInfo {
        message: "integer arithmetic fault",
        source: "reference.dever",
        line: 1,
        column: 1,
    }
}

fn roundtrip_generated(values: &[String]) -> Result<String, Fault> {
    GENERATED_ROUNDTRIP(values.first().map(String::as_str).unwrap_or(""))
}

fn roundtrip_reference(values: &[String]) -> Result<String, Fault> {
    let id = Id::from(values.first().map(String::as_str).unwrap_or("").to_owned());
    Ok(id.into_text())
}

fn encode_reference(values: &[String]) -> Result<Vec<Id>, Fault> {
    Ok(values.iter().map(|text| Id::from(text.clone())).collect())
}

fn compare_generated(values: &[Comparison]) -> Result<i64, Fault> {
    match values.first() {
        Some(value) => GENERATED_COMPARE(&value.values, &value.expected),
        None => Ok(0),
    }
}

fn compare_reference(values: &[Comparison]) -> Result<i64, Fault> {
    let Some(value) = values.first() else {
        return Ok(0);
    };
    let expected = value.expected.clone();
    let mut count = 0i64;
    for item in &value.values {
        count = count
            .checked_add(i64::from(item == &expected))
            .ok_or_else(id_fault)?;
    }
    Ok(count)
}

fn lookup_generated(values: &[Lookup]) -> Result<i64, Fault> {
    match values.first() {
        Some(value) => GENERATED_LOOKUP(&value.generated, &value.keys),
        None => Ok(0),
    }
}

fn lookup_reference(values: &[Lookup]) -> Result<i64, Fault> {
    let Some(value) = values.first() else {
        return Ok(0);
    };
    let mut count = 0i64;
    for key in &value.keys {
        count = count
            .checked_add(value.reference.get(key).copied().unwrap_or(0))
            .ok_or_else(id_fault)?;
    }
    Ok(count)
}

fn lookup_same_table(values: &[Lookup]) -> Result<i64, Fault> {
    let Some(value) = values.first() else {
        return Ok(0);
    };
    let mut count = 0i64;
    for key in &value.keys {
        count = count
            .checked_add(value.generated.get(key).copied().unwrap_or(0))
            .ok_or_else(id_fault)?;
    }
    Ok(count)
}

fn map_reference(values: &[String]) -> Result<Vec<(Id, i64)>, Fault> {
    let mut map = IndexMap::new();
    for text in values {
        map.insert(Id::from(text.clone()), text.chars().count() as i64);
    }
    Ok(map.into_iter().collect())
}

fn main() {
    let texts: Vec<String> = (0..512)
        .map(|index| format!("user-{index:04}-雪"))
        .collect();
    let short = ["user-0012-雪".to_owned()];
    let long = ["雪山树林".repeat(512)];
    let reference = || {
        texts
            .iter()
            .map(|text| (Id::from(text.clone()), text.chars().count() as i64))
            .collect()
    };
    // 建表顺序影响独立表的哈希与分配布局；复测须等量覆盖两种顺序。
    let (generated, reference) = match std::env::var("DEVER_BENCH_MAP_ORDER")
        .as_deref()
        .unwrap_or("dever-first")
    {
        "dever-first" => {
            let generated = GENERATED_BUILD_MAP(&texts).unwrap();
            (generated, reference())
        }
        "rust-first" => {
            let reference = reference();
            (GENERATED_BUILD_MAP(&texts).unwrap(), reference)
        }
        order => panic!("unknown table construction order: {order}"),
    };
    let keys = (0..1024)
        .map(|index| Id::from(format!("user-{:04}-雪", (index * 17) % 576)))
        .collect();
    let lookups = [Lookup {
        generated,
        reference,
        keys,
    }];
    let comparisons = [Comparison {
        values: (0..1024)
            .map(|index| Id::from(format!("user-{:04}-雪", index % 32)))
            .collect(),
        expected: Id::from("user-0012-雪".to_owned()),
    }];
    assert_eq!(
        GENERATED_ENTRIES(&["a".into(), "b".into(), "a".into()]).unwrap(),
        map_reference(&["a".into(), "b".into(), "a".into()]).unwrap()
    );
    println!("case,sample,implementation,elapsed_ns,checksum");
    compare(
        "id_roundtrip_short",
        &short,
        300000,
        roundtrip_generated,
        roundtrip_reference,
        |value| value.len() as u64,
    );
    compare(
        "id_roundtrip_long",
        &long,
        20000,
        roundtrip_generated,
        roundtrip_reference,
        |value| value.len() as u64,
    );
    compare(
        "id_each",
        &texts,
        300,
        GENERATED_ENCODE_ALL,
        encode_reference,
        |value| value.len() as u64,
    );
    compare(
        "id_compare",
        &comparisons,
        2000,
        compare_generated,
        compare_reference,
        |value| *value as u64,
    );
    compare(
        "id_map_lookup",
        &lookups,
        1000,
        lookup_generated,
        lookup_reference,
        |value| *value as u64,
    );
    // 双方读取同一张表，避免将各自随机哈希状态的差异归给生成代码。
    compare_named(
        "id_map_lookup_same_table",
        &lookups,
        1000,
        lookup_generated,
        lookup_same_table,
        |value| *value as u64,
        "rust_runtime",
    );
    compare(
        "id_map_build",
        &texts,
        300,
        GENERATED_ENTRIES,
        map_reference,
        |value| value.len() as u64,
    );
}