//! Every request and response example of `contracts/examples/` (SPEC §14.3.5) decodes into its wire type and
//! re-encodes to the same JSON value.

use std::path::PathBuf;

use kvitt_server::error::ErrorBody;
use kvitt_server::wire::*;
use serde::Serialize;
use serde::de::DeserializeOwned;
use serde_json::Value;

fn round_trip<T: DeserializeOwned + Serialize>(name: &str, example: &Value) {
    let decoded: T = serde_json::from_value(example.clone()).unwrap_or_else(|e| {
        panic!(
            "{name}: does not decode as {}: {e}",
            std::any::type_name::<T>()
        )
    });
    let encoded = serde_json::to_value(&decoded).unwrap();
    assert_eq!(&encoded, example, "{name}: re-encoding differs");
}

fn check(name: &str, example: &Value) -> bool {
    macro_rules! map {
        ($($file:literal => $t:ty,)*) => {
            match name {
                $($file => { round_trip::<$t>(name, example); true })*
                _ => false,
            }
        };
    }
    map! {
        "E-1-health/response.json" => Health,
        "E-2-setup-status/response.json" => SetupStatus,
        "E-3-invites-accept/request.json" => AcceptInviteRequest,
        "E-3-invites-accept/response.json" => AcceptInviteResponse,
        "E-5-apk-latest/response.json" => ApkLatest,
        "E-7-me/response.json" => MeResponse,
        "E-8-patch-me/request.json" => PatchMeRequest,
        "E-8-patch-me/response.json" => User,
        "E-9-put-me-picture/response.json" => User,
        "E-10-delete-me-picture/response.json" => User,
        "E-12-create-invite/request.json" => CreateInviteRequest,
        "E-12-create-invite/response.json" => Invite,
        "E-13-list-invites/response.json" => InviteList,
        "E-15-list-devices/response.json" => DeviceList,
        "E-17-push-token/request.json" => PushTokenRequest,
        "E-18-create-account/request.json" => CreateAccountRequest,
        "E-18-create-account/response.json" => Account,
        "E-19-patch-account/request.json" => PatchAccountRequest,
        "E-19-patch-account/response.json" => Account,
        "E-20-archive-account/response.json" => Account,
        "E-21-unarchive-account/response.json" => Account,
        "E-22-delete-account/response.json" => Account,
        "E-23-create-category/request.json" => CreateCategoryRequest,
        "E-23-create-category/response.json" => Category,
        "E-24-patch-category/request.json" => PatchCategoryRequest,
        "E-24-patch-category/response.json" => Category,
        "E-25-archive-category/response.json" => Category,
        "E-26-unarchive-category/response.json" => Category,
        "E-26-unarchive-category/response-default.json" => Category,
        "E-27-delete-category/response.json" => Category,
        "E-28-create-recurring-template/request.json" => CreateRecurringTemplateRequest,
        "E-28-create-recurring-template/response.json" => RecurringTemplate,
        "E-29-patch-recurring-template/request.json" => PatchRecurringTemplateRequest,
        "E-29-patch-recurring-template/response.json" => RecurringTemplate,
        "E-30-delete-recurring-template/response.json" => RecurringTemplate,
        "E-31-sync-pull/response.json" => SyncPullResponse,
        "E-32-sync-push/request.json" => SyncPushRequest,
        "E-32-sync-push/response.json" => SyncPushResponse,
        "E-33-settlement-proposal/request.json" => ProposalRequest,
        "E-33-settlement-proposal/response.json" => ProposalResponse,
        "sync/pull-empty-page.json" => SyncPullResponse,
        "sync/pull-page.json" => SyncPullResponse,
        "sync/pull-page-categories-v2.json" => SyncPullResponse,
        "sync/push-request.json" => SyncPushRequest,
        "sync/push-request-delete.json" => SyncPushRequest,
        "sync/push-request-rejections.json" => SyncPushRequest,
        "sync/push-response.json" => SyncPushResponse,
        "sync/push-response-delete.json" => SyncPushResponse,
        "sync/push-response-rejections.json" => SyncPushResponse,
    }
}

#[test]
fn every_example_round_trips() {
    let root = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("../../../contracts/examples");
    let mut unmapped = Vec::new();
    let mut checked = 0;
    let mut dirs: Vec<_> = std::fs::read_dir(&root)
        .unwrap()
        .map(|e| e.unwrap().path())
        .collect();
    dirs.sort();
    for dir in dirs.into_iter().filter(|p| p.is_dir()) {
        let dir_name = dir.file_name().unwrap().to_string_lossy().into_owned();
        for file in std::fs::read_dir(&dir).unwrap() {
            let path = file.unwrap().path();
            let name = format!("{dir_name}/{}", path.file_name().unwrap().to_string_lossy());
            let example: Value =
                serde_json::from_str(&std::fs::read_to_string(&path).unwrap()).unwrap();
            if dir_name == "errors" {
                round_trip::<ErrorBody>(&name, &example);
                checked += 1;
            } else if dir_name == "push" {
                // FCM payloads (SPEC §14.6) are built by the push sender, not by a wire type of this crate.
                continue;
            } else if check(&name, &example) {
                checked += 1;
            } else {
                unmapped.push(name);
            }
        }
    }
    assert!(
        unmapped.is_empty(),
        "examples without a wire type: {unmapped:?}"
    );
    assert!(checked > 60, "only {checked} examples checked");
}

#[test]
fn absent_and_null_are_distinct_where_the_contract_says_so() {
    let patch: PatchCategoryRequest = serde_json::from_str(r#"{"name": null}"#).unwrap();
    assert_eq!(patch.name, Some(None));
    let patch: PatchCategoryRequest = serde_json::from_str(r#"{"icon": "home"}"#).unwrap();
    assert_eq!(patch.name, None);
    // E-17: the key is required, the value nullable.
    assert!(serde_json::from_str::<PushTokenRequest>("{}").is_err());
    let clear: PushTokenRequest = serde_json::from_str(r#"{"fcm_token": null}"#).unwrap();
    assert_eq!(clear.fcm_token, None);
    // E-12: target_user_id may be absent.
    let invite: CreateInviteRequest = serde_json::from_str(r#"{"kind": "partner"}"#).unwrap();
    assert_eq!(invite.target_user_id, None);
}