//! Decodes the AFI fixture into the typed IR structs. Each test reads back a
//! different facet of the KDL — the function set, per-function field decoding,
//! context-param elevation, and the named-type table.

use std::path::PathBuf;

use mizan_codegen::fetch::parse_ir_from_str;
use mizan_codegen::ir::{AffectKind, CallInput, IsContext, Primitive, Transport};


fn load_fixture() -> mizan_codegen::ir::MizanIR {
    let path = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("tests/fixtures/afi_ir.kdl");
    let raw = std::fs::read_to_string(&path)
        .unwrap_or_else(|e| panic!("read {}: {e}", path.display()));
    parse_ir_from_str(&raw).unwrap_or_else(|e| panic!("parse IR: {e}"))
}


#[test]
fn afi_fixture_deserializes_function_set() {
    let ir = load_fixture();
    let names: Vec<&str> = ir.functions.iter().map(|f| f.name.as_str()).collect();

    assert_eq!(ir.functions.len(), 7, "expected 7 functions, got {}: {names:?}", ir.functions.len());

    for expected in [
        "echo", "whoami",
        "user_profile", "user_orders",
        "update_profile", "find_user", "rename_user",
    ] {
        assert!(names.contains(&expected), "missing function {expected:?} in {names:?}");
    }
}


#[test]
fn afi_fixture_function_field_decode() {
    let ir = load_fixture();
    let echo = ir.functions.iter().find(|f| f.name == "echo").unwrap();
    assert_eq!(echo.camel_name, "echo");
    assert_eq!(echo.input, CallInput::Typed("echoInput".to_string()));
    assert_eq!(echo.output_type, "echoOutput");
    assert!(!echo.output_nullable);
    assert_eq!(echo.transport, Transport::Http);
    assert_eq!(echo.is_context, IsContext::No);

    let whoami = ir.functions.iter().find(|f| f.name == "whoami").unwrap();
    assert_eq!(whoami.input, CallInput::Absent);

    // `find_user` returns `ProfileOutput | None` — outputNullable must be true.
    let find_user = ir.functions.iter().find(|f| f.name == "find_user").unwrap();
    assert!(find_user.output_nullable, "find_user must be outputNullable");

    // Context-typed function picks up the context name.
    let user_profile = ir.functions.iter().find(|f| f.name == "user_profile").unwrap();
    assert_eq!(user_profile.is_context.as_str(), Some("user"));

    // Mutation with `affects="user"` lands in `affects` as a context target.
    let update_profile = ir.functions.iter().find(|f| f.name == "update_profile").unwrap();
    assert_eq!(update_profile.affects.len(), 1);
    assert_eq!(update_profile.affects[0].kind, AffectKind::Context);
    assert_eq!(update_profile.affects[0].name, "user");

    // Mutation with `merge="user"`.
    let rename_user = ir.functions.iter().find(|f| f.name == "rename_user").unwrap();
    assert_eq!(rename_user.merge, vec!["user".to_string()]);
}


/// `has-input` and `input` are two spellings of one fact; a document that
/// spells them against each other is rejected at the KDL crossing rather than
/// silently reaching a target as a no-argument call.
#[test]
fn contradictory_input_spellings_are_rejected() {
    let declared_without_flag = r#"
function "echo" {
    camel "echo"
    has-input #false
    input "echoInput"
    output "echoOutput"
}
"#;
    let err = parse_ir_from_str(declared_without_flag)
        .expect_err("`input` with `has-input #false` must not parse")
        .to_string();
    assert!(err.contains("echoInput"), "fault must name the declared input type: {err}");

    let flag_without_type = r#"
function "echo" {
    camel "echo"
    has-input #true
    output "echoOutput"
}
"#;
    let err = parse_ir_from_str(flag_without_type)
        .expect_err("`has-input #true` with no `input` must not parse")
        .to_string();
    assert!(err.contains("has-input"), "fault must name `has-input`: {err}");
}


#[test]
fn afi_fixture_context_param_elevation() {
    let ir = load_fixture();
    let user = ir.contexts.get("user").expect("user context group");

    // Both context functions share `user_id` as a required param.
    let user_id = user.params.get("user_id").expect("user_id param");
    assert_eq!(user_id.ty, Primitive::Integer);
    assert!(user_id.required, "user_id is required (declared by every fn in the group)");
    assert!(user_id.shared_by.contains(&"user_profile".to_string()));
    assert!(user_id.shared_by.contains(&"user_orders".to_string()));
}


#[test]
fn afi_fixture_named_types_present() {
    let ir = load_fixture();
    // Every function names its `<camelName>Input` / `<camelName>Output` type,
    // so the IR's type table must declare each one.
    for expected in [
        "echoInput", "echoOutput",
        "whoamiOutput",
        "userProfileInput", "userProfileOutput",
        "userOrdersInput",
        "updateProfileInput", "updateProfileOutput",
        "findUserInput", "findUserOutput",
        "renameUserInput", "renameUserOutput",
    ] {
        assert!(ir.types.contains_key(expected), "missing type {expected:?}");
    }
}