nescript/src/analyzer/tests.rs

use super::*;
use crate::errors::ErrorCode;
use crate::parser;

fn analyze_ok(input: &str) -> AnalysisResult {
    let (prog, diags) = parser::parse(input);
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let prog = prog.unwrap();
    let result = analyze(&prog);
    assert!(
        result.diagnostics.iter().all(|d| !d.is_error()),
        "analysis errors: {:?}",
        result.diagnostics
    );
    result
}

fn analyze_errors(input: &str) -> Vec<ErrorCode> {
    let (prog, parse_diags) = parser::parse(input);
    if prog.is_none() {
        return parse_diags.into_iter().map(|d| d.code).collect();
    }
    let result = analyze(&prog.unwrap());
    result.diagnostics.into_iter().map(|d| d.code).collect()
}

#[test]
fn analyze_minimal_program() {
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        var px: u8 = 128
        on frame { px = 1 }
        start Main
    "#,
    );
    assert!(result.symbols.contains_key("px"));
    assert_eq!(result.var_allocations.len(), 1);
}

#[test]
fn analyze_allocates_zero_page() {
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        var x: u8 = 0
        var y: u8 = 0
        on frame { x = 1 }
        start Main
    "#,
    );
    // u8 vars should be allocated in zero page starting at $10
    assert_eq!(result.var_allocations[0].address, 0x10);
    assert_eq!(result.var_allocations[1].address, 0x11);
}

#[test]
fn analyze_duplicate_var() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        var x: u8 = 0
        var x: u8 = 1
        on frame { x = 1 }
        start Main
    "#,
    );
    assert!(errors.contains(&ErrorCode::E0501));
}

#[test]
fn analyze_undefined_transition() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        state Main {
            on frame { transition Nonexistent }
        }
        start Main
    "#,
    );
    assert!(errors.contains(&ErrorCode::E0404));
}

#[test]
fn analyze_valid_transition() {
    let _result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        state Main {
            on frame { transition Other }
        }
        state Other {
            on frame { wait_frame }
        }
        start Main
    "#,
    );
}

#[test]
fn analyze_start_state_exists() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        state Main {
            on frame { wait_frame }
        }
        start Nonexistent
    "#,
    );
    assert!(errors.contains(&ErrorCode::E0404));
}

#[test]
fn analyze_const_symbol() {
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        const SPEED: u8 = 2
        var px: u8 = 0
        on frame { px = SPEED }
        start Main
    "#,
    );
    let sym = result.symbols.get("SPEED").unwrap();
    assert!(sym.is_const);
}

#[test]
fn analyze_function_registered() {
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        fun add(a: u8, b: u8) -> u8 { return a }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(result.symbols.contains_key("add"));
}

#[test]
fn analyze_recursion_detected() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun a() { a() }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(errors.contains(&ErrorCode::E0402));
}

#[test]
fn analyze_mutual_recursion() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun a() { b() }
        fun b() { a() }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(errors.contains(&ErrorCode::E0402));
}

#[test]
fn analyze_call_depth_ok() {
    // 3 levels of nesting — well within the default limit of 8
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        fun c() { wait_frame }
        fun b() { c() }
        fun a() { b() }
        on frame { a() }
        start Main
    "#,
    );
    // The frame handler's depth should be <= 8
    for &depth in result.max_depths.values() {
        assert!(depth <= 8, "depth {depth} should be within limit");
    }
}

#[test]
fn analyze_call_depth_exceeded() {
    // Build a call chain deeper than 8: f1 -> f2 -> ... -> f10
    let result = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun f10() { wait_frame }
        fun f9() { f10() }
        fun f8() { f9() }
        fun f7() { f8() }
        fun f6() { f7() }
        fun f5() { f6() }
        fun f4() { f5() }
        fun f3() { f4() }
        fun f2() { f3() }
        fun f1() { f2() }
        on frame { f1() }
        start Main
    "#,
    );
    assert!(
        result.contains(&ErrorCode::E0401),
        "expected E0401 for exceeded call depth, got: {result:?}"
    );
}

#[test]
fn analyze_undefined_function() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        on frame { no_such_fn() }
        start Main
    "#,
    );
    assert!(errors.contains(&ErrorCode::E0503));
}

#[test]
fn analyze_call_arity_mismatch() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun add(a: u8, b: u8) -> u8 { return a }
        on frame { add(1) }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0203),
        "calling with wrong argument count should produce E0203, got: {errors:?}"
    );
}

#[test]
fn analyze_call_arity_ok() {
    analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        fun add(a: u8, b: u8) -> u8 { return a }
        on frame { add(1, 2) }
        start Main
    "#,
    );
}

#[test]
fn analyze_call_arity_in_expr_context() {
    // Calls used as expressions should also be checked.
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun two(a: u8, b: u8) -> u8 { return a }
        var x: u8 = 0
        on frame { x = two(1) }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0203),
        "call arity error in expression context should still trigger E0203: {errors:?}"
    );
}

#[test]
fn analyze_return_type_ok() {
    analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        fun get_five() -> u8 { return 5 }
        on frame { wait_frame }
        start Main
    "#,
    );
}

#[test]
fn analyze_return_wrong_type() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun is_ok() -> bool { return 5 }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0201),
        "returning wrong type should produce E0201, got: {errors:?}"
    );
}

#[test]
fn analyze_struct_variable_allocates_fields() {
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        struct Vec2 { x: u8, y: u8 }
        var pos: Vec2
        on frame {
            pos.x = 10
            pos.y = pos.x
        }
        start Main
    "#,
    );
    // The analyzer should synthesize pos.x and pos.y as separate
    // variables with consecutive addresses.
    let px = result
        .var_allocations
        .iter()
        .find(|a| a.name == "pos.x")
        .expect("pos.x should be allocated");
    let py = result
        .var_allocations
        .iter()
        .find(|a| a.name == "pos.y")
        .expect("pos.y should be allocated");
    assert_eq!(py.address, px.address + 1);
}

#[test]
fn analyze_struct_u16_field_allocates_two_bytes() {
    // A struct with a u16 field should lay out fields with
    // byte-accurate offsets: a u8 followed by a u16 followed by a u8
    // puts `b` at offset 1 and `c` at offset 3.
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        struct Mixed { a: u8, b: u16, c: u8 }
        var m: Mixed
        on frame {
            m.a = 1
            m.b = 300
            m.c = 7
        }
        start Main
    "#,
    );
    let a = result
        .var_allocations
        .iter()
        .find(|x| x.name == "m.a")
        .expect("m.a should be allocated");
    let b = result
        .var_allocations
        .iter()
        .find(|x| x.name == "m.b")
        .expect("m.b should be allocated");
    let c = result
        .var_allocations
        .iter()
        .find(|x| x.name == "m.c")
        .expect("m.c should be allocated");
    // Offsets from base: a=0, b=1, c=3 (b is two bytes wide).
    assert_eq!(b.address, a.address + 1);
    assert_eq!(c.address, a.address + 3);
    // u16 field is recorded with size 2 so codegen bookkeeping
    // knows how much space the field occupies.
    assert_eq!(a.size, 1);
    assert_eq!(b.size, 2);
    assert_eq!(c.size, 1);
}

#[test]
fn analyze_struct_with_array_field_is_rejected() {
    // Array fields are still rejected — the analyzer only accepts
    // u8/i8/u16/bool scalar fields in v1 structs.
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        struct Bag { xs: u8[4] }
        var b: Bag
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0201),
        "array struct field should emit E0201: {errors:?}"
    );
}

#[test]
fn analyze_struct_with_nested_struct_field_is_rejected() {
    // Nested struct fields are still rejected — only scalar primitives.
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        struct Inner { a: u8 }
        struct Outer { inner: Inner }
        var o: Outer
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0201),
        "nested struct field should emit E0201: {errors:?}"
    );
}

#[test]
fn analyze_struct_unknown_field_errors() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        struct Vec2 { x: u8, y: u8 }
        var pos: Vec2
        on frame { pos.z = 5 }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0201),
        "unknown field should emit E0201: {errors:?}"
    );
}

#[test]
fn analyze_unknown_struct_type_errors() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        var pos: NoSuchStruct
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0201),
        "unknown struct type should emit E0201: {errors:?}"
    );
}

#[test]
fn analyze_assign_to_undefined_var_errors() {
    // Assigning to an undeclared variable must produce E0502
    // rather than silently creating the variable.
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        on frame { nope = 5 }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0502),
        "assignment to undefined var should produce E0502, got: {errors:?}"
    );
}

#[test]
fn analyze_enum_variants_as_constants() {
    let result = analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        enum Color { Red, Green, Blue }
        var c: u8 = Red
        on frame {
            if c == Blue { c = Green }
        }
        start Main
    "#,
    );
    // Variants should be registered as constant symbols.
    assert!(result.symbols.get("Red").is_some_and(|s| s.is_const));
    assert!(result.symbols.get("Green").is_some_and(|s| s.is_const));
    assert!(result.symbols.get("Blue").is_some_and(|s| s.is_const));
}

#[test]
fn analyze_duplicate_enum_variant_errors() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        enum A { Foo, Bar }
        enum B { Baz, Bar }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0501),
        "duplicate variant should emit E0501, got: {errors:?}"
    );
}

#[test]
fn analyze_dead_code_after_break() {
    let src = r#"
        game "Test" { mapper: NROM }
        var x: u8 = 0
        on frame {
            loop {
                break
                x += 1
            }
        }
        start Main
    "#;
    let errors = analyze_errors(src);
    assert!(
        errors.contains(&ErrorCode::W0104),
        "code after break should trigger W0104, got: {errors:?}"
    );
}

#[test]
fn analyze_dead_code_after_transition() {
    let src = r#"
        game "Test" { mapper: NROM }
        state A {
            on frame {
                transition B
                wait_frame
            }
        }
        state B { on frame { wait_frame } }
        start A
    "#;
    let errors = analyze_errors(src);
    assert!(
        errors.contains(&ErrorCode::W0104),
        "code after transition should trigger W0104, got: {errors:?}"
    );
}

#[test]
fn analyze_dead_code_after_return_in_fn() {
    let src = r#"
        game "Test" { mapper: NROM }
        fun foo() -> u8 {
            return 5
            return 6
        }
        on frame { wait_frame }
        start Main
    "#;
    let errors = analyze_errors(src);
    assert!(
        errors.contains(&ErrorCode::W0104),
        "code after return should trigger W0104, got: {errors:?}"
    );
}

#[test]
fn analyze_ram_overflow_emits_e0301() {
    // Two arrays totalling >2 KB cannot fit in NES RAM, triggering
    // E0301 at allocation time.
    let src = r#"
        game "Test" { mapper: NROM }
        var huge: u8[2000]
        var also_huge: u8[2000]
        on frame { wait_frame }
        start Main
    "#;
    let errors = analyze_errors(src);
    assert!(
        errors.contains(&ErrorCode::E0301),
        "RAM overflow should produce E0301, got: {errors:?}"
    );
}

#[test]
fn analyze_expensive_multiply_warns() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        var a: u8 = 3
        var b: u8 = 5
        var c: u8 = 0
        on frame { c = a * b }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::W0101),
        "variable*variable multiply should emit W0101, got: {errors:?}"
    );
}

#[test]
fn analyze_multiply_by_constant_ok() {
    // Multiply by a literal is cheap (strength reduced to shifts).
    analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        var a: u8 = 3
        var c: u8 = 0
        on frame { c = a * 4 }
        start Main
    "#,
    );
}

#[test]
fn analyze_on_scanline_requires_mmc3() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        state Main {
            on frame { wait_frame }
            on scanline(120) { scroll(0, 0) }
        }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0203),
        "on scanline without MMC3 should produce E0203, got: {errors:?}"
    );
}

#[test]
fn analyze_on_scanline_mmc3_ok() {
    analyze_ok(
        r#"
        game "Test" { mapper: MMC3 }
        state Main {
            on frame { wait_frame }
            on scanline(120) { scroll(0, 0) }
        }
        start Main
    "#,
    );
}

#[test]
fn analyze_loop_without_exit_warns() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        var x: u8 = 0
        on frame {
            loop { x += 1 }
        }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::W0102),
        "infinite loop with no exit should produce W0102, got: {errors:?}"
    );
}

#[test]
fn analyze_loop_with_wait_frame_ok() {
    analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        on frame {
            loop { wait_frame }
        }
        start Main
    "#,
    );
}

#[test]
fn analyze_loop_with_break_ok() {
    analyze_ok(
        r#"
        game "Test" { mapper: NROM }
        var x: u8 = 0
        on frame {
            loop {
                x += 1
                if x == 10 { break }
            }
        }
        start Main
    "#,
    );
}

#[test]
fn analyze_bare_return_from_typed_fn_errors() {
    // A `return` with no value inside a function that has a declared
    // return type should produce E0203.
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun get_five() -> u8 {
            return
        }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0203),
        "bare return from typed fn should produce E0203, got: {errors:?}"
    );
}

#[test]
fn analyze_return_value_from_void_fn() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        fun do_nothing() { return 5 }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0203),
        "returning value from void function should produce E0203, got: {errors:?}"
    );
}

#[test]
fn analyze_const_assignment_error() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        const SPEED: u8 = 2
        on frame { SPEED = 5 }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0203),
        "assigning to const should produce E0203, got: {errors:?}"
    );
}

#[test]
fn analyze_break_outside_loop() {
    let errors = analyze_errors(
        r#"
        game "Test" { mapper: NROM }
        on frame { break }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0203),
        "break outside loop should produce E0203, got: {errors:?}"
    );
}

#[test]
fn analyze_unused_variable_warning() {
    // `ghost` is declared but never read (only the initializer runs).
    // It should trigger a W0103 warning.
    let (prog, diags) = parser::parse(
        r#"
        game "Test" { mapper: NROM }
        var ghost: u8 = 0
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let result = analyze(&prog.unwrap());
    assert!(
        result.diagnostics.iter().any(|d| d.code == ErrorCode::W0103
            && d.level == crate::errors::Level::Warning
            && d.message.contains("ghost")),
        "expected W0103 for unused var 'ghost', got: {:?}",
        result.diagnostics
    );
    // And no hard errors.
    assert!(
        result.diagnostics.iter().all(|d| !d.is_error()),
        "unexpected hard errors: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_unused_state_local_warning() {
    // State-local `bonus` is declared but never read — W0103 should fire.
    let (prog, diags) = parser::parse(
        r#"
        game "Test" { mapper: NROM }
        state Main {
            var bonus: u8 = 0
            on frame { wait_frame }
        }
        start Main
    "#,
    );
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let result = analyze(&prog.unwrap());
    assert!(
        result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0103 && d.message.contains("bonus")),
        "expected W0103 for unused state-local 'bonus', got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_unused_variable_no_warning_when_read() {
    // `counter` is both written and read (in the `if` condition),
    // so W0103 should NOT fire for it.
    let (prog, diags) = parser::parse(
        r#"
        game "Test" { mapper: NROM }
        var counter: u8 = 0
        on frame {
            counter = counter + 1
            if counter > 60 { wait_frame }
        }
        start Main
    "#,
    );
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let result = analyze(&prog.unwrap());
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0103 && d.message.contains("counter")),
        "did not expect W0103 for read variable 'counter', got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_unused_variable_underscore_prefix_silences() {
    // A leading underscore silences the W0103 warning, matching Rust's
    // convention for intentionally-unused names.
    let (prog, diags) = parser::parse(
        r#"
        game "Test" { mapper: NROM }
        var _reserved: u8 = 0
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let result = analyze(&prog.unwrap());
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0103),
        "did not expect W0103 for underscore-prefixed var, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_unreachable_state_warning() {
    // `Orphan` is never reached from `Main` — W0104 should fire.
    let (prog, diags) = parser::parse(
        r#"
        game "Test" { mapper: NROM }
        state Main {
            on frame { wait_frame }
        }
        state Orphan {
            on frame { wait_frame }
        }
        start Main
    "#,
    );
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let result = analyze(&prog.unwrap());
    assert!(
        result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0104 && d.message.contains("Orphan")),
        "expected W0104 for unreachable state 'Orphan', got: {:?}",
        result.diagnostics
    );
    // And no hard errors.
    assert!(
        result.diagnostics.iter().all(|d| !d.is_error()),
        "unexpected hard errors: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_reachable_state_no_warning() {
    // Both states are reachable: Main transitions to Other, and Other
    // transitions back to Main. Neither should trigger W0104.
    let (prog, diags) = parser::parse(
        r#"
        game "Test" { mapper: NROM }
        state Main {
            on frame { transition Other }
        }
        state Other {
            on frame { transition Main }
        }
        start Main
    "#,
    );
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let result = analyze(&prog.unwrap());
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0104),
        "did not expect any W0104 warnings, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_undefined_variable_emits_e0502() {
    // `ghosy` does not exist; analyzer should emit E0502 and — thanks to
    // the suggestion helper — hint at `ghost` which is the close match.
    let (prog, diags) = parser::parse(
        r#"
        game "Test" { mapper: NROM }
        var ghost: u8 = 0
        var score: u8 = 0
        on frame {
            score = ghosy + 1
        }
        start Main
    "#,
    );
    assert!(diags.is_empty(), "parse errors: {diags:?}");
    let result = analyze(&prog.unwrap());
    let diag = result
        .diagnostics
        .iter()
        .find(|d| d.code == ErrorCode::E0502)
        .expect("expected E0502 for undefined variable 'ghosy'");
    assert!(
        diag.message.contains("ghosy"),
        "E0502 message should mention 'ghosy', got: {}",
        diag.message
    );
    assert_eq!(
        diag.help.as_deref(),
        Some("did you mean 'ghost'?"),
        "expected suggestion for 'ghost', got: {:?}",
        diag.help
    );
}

// ── Audio name validation ──

#[test]
fn analyze_accepts_builtin_sfx() {
    // `play coin` is always valid because `coin` is a builtin
    // even without a user `sfx Coin { ... }` declaration.
    analyze_ok(
        r#"
        game "T" { mapper: NROM }
        on frame { play coin }
        start Main
    "#,
    );
}

#[test]
fn analyze_accepts_user_declared_sfx() {
    analyze_ok(
        r#"
        game "T" { mapper: NROM }
        sfx Chime {
            pitch: [0x20, 0x22, 0x24, 0x26]
            volume: [15, 12, 8, 4]
        }
        on frame { play Chime }
        start Main
    "#,
    );
}

#[test]
fn analyze_rejects_unknown_sfx_name() {
    // `play Nonexistent` with no matching user decl or builtin
    // should emit E0505.
    let codes = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        on frame { play Nonexistent }
        start Main
    "#,
    );
    assert!(
        codes.contains(&ErrorCode::E0505),
        "expected E0505 for unknown sfx, got {codes:?}"
    );
}

#[test]
fn analyze_accepts_builtin_music() {
    analyze_ok(
        r#"
        game "T" { mapper: NROM }
        on frame { start_music theme }
        start Main
    "#,
    );
}

#[test]
fn analyze_accepts_user_declared_music() {
    analyze_ok(
        r#"
        game "T" { mapper: NROM }
        music Boss {
            notes: [37, 8, 41, 8, 44, 8, 49, 8]
        }
        on frame { start_music Boss }
        start Main
    "#,
    );
}

#[test]
fn analyze_rejects_unknown_music_name() {
    let codes = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        on frame { start_music Nonexistent }
        start Main
    "#,
    );
    assert!(
        codes.contains(&ErrorCode::E0505),
        "expected E0505 for unknown music, got {codes:?}"
    );
}

#[test]
fn analyze_stop_music_needs_no_name_and_is_always_valid() {
    // `stop_music` takes no argument, so there's nothing to
    // validate — it should always analyze cleanly.
    analyze_ok(
        r#"
        game "T" { mapper: NROM }
        on frame { stop_music }
        start Main
    "#,
    );
}

// ── Palette / background validation ──

#[test]
fn analyze_accepts_declared_palette() {
    analyze_ok(
        r#"
        game "T" { mapper: NROM }
        palette Cool { colors: [0x0F, 0x01, 0x11, 0x21] }
        on frame { set_palette Cool }
        start Main
    "#,
    );
}

#[test]
fn analyze_rejects_unknown_palette() {
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        on frame { set_palette Ghost }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0502),
        "expected E0502 for unknown palette, got {errors:?}"
    );
}

#[test]
fn analyze_accepts_declared_background() {
    analyze_ok(
        r#"
        game "T" { mapper: NROM }
        background Stage { tiles: [0, 1, 2] }
        on frame { load_background Stage }
        start Main
    "#,
    );
}

#[test]
fn analyze_rejects_unknown_background() {
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        on frame { load_background Ghost }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0502),
        "expected E0502 for unknown background, got {errors:?}"
    );
}

#[test]
fn analyze_rejects_palette_color_out_of_range() {
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        palette Bad { colors: [0x0F, 0x40] }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0201),
        "expected E0201 for out-of-range NES color, got {errors:?}"
    );
}

#[test]
fn analyze_rejects_palette_too_long() {
    // 33 bytes > 32-byte PPU palette RAM limit.
    let colors = (0..33)
        .map(|_| "0x0F".to_string())
        .collect::<Vec<_>>()
        .join(", ");
    let src = format!(
        r#"
        game "T" {{ mapper: NROM }}
        palette Big {{ colors: [{colors}] }}
        on frame {{ wait_frame }}
        start Main
    "#
    );
    let errors = analyze_errors(&src);
    assert!(
        errors.contains(&ErrorCode::E0201),
        "expected E0201 for >32-byte palette, got {errors:?}"
    );
}

#[test]
fn analyze_rejects_background_tiles_too_long() {
    // 961 bytes > 960-byte nametable.
    let tiles = (0..961)
        .map(|_| "0".to_string())
        .collect::<Vec<_>>()
        .join(", ");
    let src = format!(
        r#"
        game "T" {{ mapper: NROM }}
        background Big {{ tiles: [{tiles}] }}
        on frame {{ wait_frame }}
        start Main
    "#
    );
    let errors = analyze_errors(&src);
    assert!(
        errors.contains(&ErrorCode::E0201),
        "expected E0201 for >960-byte nametable, got {errors:?}"
    );
}

#[test]
fn analyze_rejects_duplicate_palette_name() {
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        palette Dup { colors: [0x0F] }
        palette Dup { colors: [0x10] }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::E0501),
        "expected E0501 for duplicate palette name, got {errors:?}"
    );
}

#[test]
fn analyze_reserves_zero_page_when_palette_declared() {
    // When a program declares any palette or background, the
    // analyzer bumps the user zero-page start from $10 to $18 so
    // the runtime can own $11-$17 for the vblank update handshake.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        palette P { colors: [0x0F] }
        var x: u8 = 0
        on frame { wait_frame }
        start Main
    "#,
    );
    let x = result
        .var_allocations
        .iter()
        .find(|a| a.name == "x")
        .expect("x should be allocated");
    assert!(
        x.address >= 0x18,
        "user var `x` should land at $18+ when palette is declared (got ${:02X})",
        x.address
    );
}

#[test]
fn analyze_does_not_reserve_zero_page_without_palette_or_bg() {
    // Programs that don't declare palette/background keep the old
    // user-ZP start at $10 so existing examples (and their
    // goldens) don't shift.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        var x: u8 = 0
        on frame { wait_frame }
        start Main
    "#,
    );
    let x = result
        .var_allocations
        .iter()
        .find(|a| a.name == "x")
        .expect("x should be allocated");
    assert_eq!(x.address, 0x10);
}

// ── W0102 extended: `while true` + continue-only loops ──────

#[test]
fn analyze_while_true_without_exit_warns() {
    // `while true { x = x + 1 }` — no break/return/wait_frame,
    // so the same W0102 that fires on bare `loop { ... }` must
    // also fire here.
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        var x: u8 = 0
        on frame {
            while true { x = x + 1 }
        }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::W0102),
        "`while true` with no exit should produce W0102, got: {errors:?}"
    );
}

#[test]
fn analyze_while_true_with_wait_frame_ok() {
    // `while true { wait_frame }` yields control to the NMI each
    // iteration, so the NES actually makes progress — no warning.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        on frame {
            while true { wait_frame }
        }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0102),
        "`while true` + wait_frame should NOT warn, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_while_true_with_break_ok() {
    // A reachable `break` satisfies W0102 just like it does for
    // bare `loop`.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        var x: u8 = 0
        on frame {
            while true {
                x = x + 1
                if x == 10 { break }
            }
        }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0102),
        "`while true` + break should NOT warn, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_loop_with_only_continue_still_warns() {
    // `continue` is *not* an exit — the loop still spins forever.
    // W0102 must still fire here.
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        var x: u8 = 0
        on frame {
            loop {
                if x == 0 { continue }
            }
        }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::W0102),
        "`loop` whose only exit is `continue` should still produce W0102, got: {errors:?}"
    );
}

// ── W0105: palette universal-byte consistency ───────────────

#[test]
fn analyze_palette_consistent_universals_ok() {
    // Flat-form palette where every sub-palette's first byte is
    // the same universal colour ($0F = black). No W0105.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        palette Consistent {
            colors: [
                0x0F, 0x11, 0x12, 0x13,
                0x0F, 0x21, 0x22, 0x23,
                0x0F, 0x31, 0x32, 0x33,
                0x0F, 0x01, 0x02, 0x03,
                0x0F, 0x05, 0x06, 0x07,
                0x0F, 0x15, 0x16, 0x17,
                0x0F, 0x25, 0x26, 0x27,
                0x0F, 0x35, 0x36, 0x37
            ]
        }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0105),
        "consistent palette should NOT warn, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_palette_inconsistent_universals_warns() {
    // Flat-form palette whose sub-palette first bytes disagree
    // (index 0 = $0F, index 16 = $30, etc.) — the $3F10 mirror
    // will overwrite the background universal colour at runtime.
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        palette Broken {
            colors: [
                0x0F, 0x11, 0x12, 0x13,
                0x0F, 0x21, 0x22, 0x23,
                0x0F, 0x31, 0x32, 0x33,
                0x0F, 0x01, 0x02, 0x03,
                0x30, 0x05, 0x06, 0x07,
                0x0F, 0x15, 0x16, 0x17,
                0x0F, 0x25, 0x26, 0x27,
                0x0F, 0x35, 0x36, 0x37
            ]
        }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::W0105),
        "inconsistent palette universals should produce W0105, got: {errors:?}"
    );
}

#[test]
fn analyze_grouped_palette_is_always_consistent() {
    // The grouped form uses the `universal:` field to drive
    // every sub-palette's first byte, so it can never trip
    // W0105 — even when the sub-palette bodies differ wildly.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        palette Grouped {
            universal: 0x0F
            bg0: [0x11, 0x12, 0x13]
            bg1: [0x21, 0x22, 0x23]
            bg2: [0x31, 0x32, 0x33]
            bg3: [0x01, 0x02, 0x03]
            sp0: [0x05, 0x06, 0x07]
            sp1: [0x15, 0x16, 0x17]
            sp2: [0x25, 0x26, 0x27]
            sp3: [0x35, 0x36, 0x37]
        }
        on frame { wait_frame }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0105),
        "grouped palette should never trip W0105, got: {:?}",
        result.diagnostics
    );
}

// ── W0106: implicit drop of a function return value ─────────

#[test]
fn analyze_discarded_non_void_return_warns() {
    // `double(x)` returns u8 but the caller drops the result.
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        var x: u8 = 0
        fun double(n: u8) -> u8 { return n + n }
        on frame { double(x) }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::W0106),
        "discarded non-void return should produce W0106, got: {errors:?}"
    );
}

#[test]
fn analyze_discarded_void_call_ok() {
    // Void function at statement position is the happy path —
    // no discarded value, no warning.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        var x: u8 = 0
        fun bump() { x = x + 1 }
        on frame { bump() }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0106),
        "void call should NOT produce W0106, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_non_void_return_used_as_rhs_ok() {
    // Same signature as the discarded case, but the return value
    // is consumed by an assignment — no warning.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        var x: u8 = 0
        var y: u8 = 0
        fun double(n: u8) -> u8 { return n + n }
        on frame { y = double(x) }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0106),
        "assigned return value should NOT produce W0106, got: {:?}",
        result.diagnostics
    );
}

// ── W0107: `fast` variable slot under-use ───────────────────

#[test]
fn analyze_fast_var_underused_warns() {
    // `counter` is declared `fast` but only one read (in the
    // `if` condition), so its access count is 1 — below the
    // threshold of 3. W0107 should fire.
    let errors = analyze_errors(
        r#"
        game "T" { mapper: NROM }
        fast var counter: u8 = 0
        on frame {
            if counter == 0 { wait_frame }
        }
        start Main
    "#,
    );
    assert!(
        errors.contains(&ErrorCode::W0107),
        "under-used `fast` var should produce W0107, got: {errors:?}"
    );
}

#[test]
fn analyze_fast_var_heavy_use_ok() {
    // Three-plus accesses (one init + one read + one write-back)
    // is enough to justify the slot — no W0107.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        fast var counter: u8 = 0
        on frame {
            counter = counter + 1
            if counter == 0 { wait_frame }
        }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0107),
        "hot `fast` var should NOT warn, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_non_fast_var_never_warns() {
    // Only `fast` declarations are checked — a plain `var` with
    // the same (light) access pattern must not fire W0107.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        var counter: u8 = 0
        on frame {
            if counter == 0 { wait_frame }
        }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0107),
        "plain `var` should never trip W0107, got: {:?}",
        result.diagnostics
    );
}

#[test]
fn analyze_fast_var_underscore_exempt() {
    // Leading-underscore names are exempt from W0107, mirroring
    // the W0103 convention for deliberately-unused variables.
    let result = analyze_ok(
        r#"
        game "T" { mapper: NROM }
        fast var _reserved: u8 = 0
        on frame {
            if _reserved == 0 { wait_frame }
        }
        start Main
    "#,
    );
    assert!(
        !result
            .diagnostics
            .iter()
            .any(|d| d.code == ErrorCode::W0107),
        "underscore-prefixed `fast` var should be exempt, got: {:?}",
        result.diagnostics
    );
}