openjd-model 0.1.0

// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// Copyright by contributors to this project.
// SPDX-License-Identifier: (Apache-2.0 OR MIT)

//! Template parsing: YAML/JSON decoding and dispatch by specificationVersion.
//!
//! Mirrors Python `_parse.py`.

use std::str::FromStr;

use crate::error::{path_field, ModelError, ValidationErrors};
use crate::template::constrained_strings::ExtensionName;
use crate::template::validation as validate;
use crate::template::{EnvironmentTemplate, JobTemplate};
use crate::types::{
    CallerLimits, Extensions, ModelExtension, SpecificationRevision, TemplateSpecificationVersion,
    ValidationContext,
};

/// Document format.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum DocumentType {
    Json,
    Yaml,
}

/// Maximum structural nesting depth for template documents.
///
/// A valid OpenJD template reaches at most ~8 levels of nesting
/// (e.g. `steps[0].script.embeddedFiles[0].data`). 128 is generous
/// while preventing stack exhaustion from pathological inputs.
///
/// Matches `serde_json`'s hardcoded recursion limit so both formats
/// behave identically on deeply nested input.
pub const MAX_DOCUMENT_DEPTH: usize = 128;

/// Parse a string into a generic YAML/JSON object.
///
/// When `caller_limits.max_template_size` is set, the document is rejected
/// if its byte length exceeds the limit (checked before parsing).
pub fn document_string_to_object(
    document: &str,
    doc_type: DocumentType,
    caller_limits: &CallerLimits,
) -> Result<serde_json::Value, ModelError> {
    if let Some(max) = caller_limits.max_template_size {
        if document.len() > max {
            return Err(ModelError::ModelValidation(ValidationErrors::single(
                format!(
                    "Template document size ({} bytes) exceeds caller limit of {max} bytes.",
                    document.len()
                ),
            )));
        }
    }

    let parsed: serde_json::Value = match doc_type {
        DocumentType::Json => serde_json::from_str(document).map_err(|e| {
            ModelError::DecodeValidation(format!(
                "The document is not a valid JSON document consisting of key-value pairs. {e}"
            ))
        })?,
        DocumentType::Yaml => {
            let options = serde_saphyr::options! {
                strict_booleans: true,
                budget: serde_saphyr::budget! {
                    max_depth: MAX_DOCUMENT_DEPTH,
                },
            };
            serde_saphyr::from_str_with_options(document, options).map_err(|e| {
                ModelError::DecodeValidation(format!(
                    "The document is not a valid YAML document consisting of key-value pairs. {e}"
                ))
            })?
        }
    };

    if !parsed.is_object() {
        return Err(ModelError::DecodeValidation(format!(
            "The document is not a valid {doc_type:?} document consisting of key-value pairs."
        )));
    }

    Ok(parsed)
}

/// Validate a template's `extensions` list against the library's known
/// set and the caller's allowlist, accumulating problems into
/// `errors`.
///
/// The returned [`Extensions`] contains every entry that was both
/// recognized by [`ModelExtension`] and permitted by
/// `supported_extensions`. Invalid entries don't stop the function;
/// they're reported via `errors` and skipped, so the caller sees every
/// problem in one validation pass.
///
/// Problems reported, each at path `extensions`:
///
/// * Empty list: `"if provided, must be a non-empty list."`
/// * One or more duplicate names: a single aggregated message
///   `"Duplicate values for extension name are not allowed. Duplicate values: A,B,C"`
///   (values are sorted for stable output).
/// * One or more unrecognized or not-permitted names: a single
///   aggregated message
///   `"Unsupported extension names: A, B, C"` (sorted).
///
/// The duplicate pass and the unsupported pass run independently —
/// callers see errors from both when both apply, matching the Python
/// Pydantic reference implementation.
fn validate_extensions_list(
    template_exts: Option<&[ExtensionName]>,
    supported_extensions: Option<&[&str]>,
    errors: &mut ValidationErrors,
) -> Extensions {
    let path = path_field(&[], "extensions");
    let mut result = Extensions::new();

    let Some(exts) = template_exts else {
        return result;
    };

    if exts.is_empty() {
        errors.add(&path, "if provided, must be a non-empty list.");
        return result;
    }

    // Duplicate detection: collect all names that appear more than once,
    // report them in a single message with a stable (sorted) order.
    let mut seen: std::collections::HashSet<&str> = std::collections::HashSet::new();
    let mut duplicates: std::collections::BTreeSet<&str> = std::collections::BTreeSet::new();
    for ext in exts {
        let name = ext.as_str();
        if !seen.insert(name) {
            duplicates.insert(name);
        }
    }
    if !duplicates.is_empty() {
        let joined: Vec<&str> = duplicates.iter().copied().collect();
        errors.add(
            &path,
            format!(
                "Duplicate values for extension name are not allowed. Duplicate values: {}",
                joined.join(",")
            ),
        );
    }

    // Support/recognition: a name is "supported" iff it's in the caller's
    // allowlist AND is a recognized ModelExtension. Both checks collapse
    // into a single "Unsupported extension names" message to match
    // Python's wording and to avoid two near-identical errors for the
    // common "caller didn't enable the extension" case.
    let allowlist: std::collections::HashSet<&str> = supported_extensions
        .unwrap_or(&[])
        .iter()
        .copied()
        .collect();
    let mut unsupported: std::collections::BTreeSet<&str> = std::collections::BTreeSet::new();
    for ext in exts {
        let name = ext.as_str();
        match (
            ModelExtension::from_str(name).ok(),
            allowlist.contains(name),
        ) {
            (Some(known), true) => {
                result.insert(known);
            }
            _ => {
                unsupported.insert(name);
            }
        }
    }
    if !unsupported.is_empty() {
        let joined: Vec<&str> = unsupported.iter().copied().collect();
        errors.add(
            &path,
            format!("Unsupported extension names: {}", joined.join(", ")),
        );
    }

    result
}

/// Decode and validate a job template from a YAML value.
pub fn decode_job_template(
    template: serde_json::Value,
    supported_extensions: Option<&[&str]>,
    caller_limits: &CallerLimits,
) -> Result<JobTemplate, ModelError> {
    // Extract specificationVersion
    let version_str = template
        .get("specificationVersion")
        .and_then(|v| v.as_str())
        .map(|s| s.to_string())
        .ok_or_else(|| {
            ModelError::DecodeValidation(
                "Template is missing Open Job Description schema version key: specificationVersion"
                    .to_string(),
            )
        })?;

    let version = TemplateSpecificationVersion::from_str(&version_str)
        .map_err(|_| {
            let allowed = TemplateSpecificationVersion::JobTemplate2023_09.as_str();
            ModelError::DecodeValidation(format!(
                "Unknown template version: {version_str}. Values allowed for 'specificationVersion' in Job Templates are: {allowed}"
            ))
        })?;

    if !version.is_job_template() {
        let allowed = TemplateSpecificationVersion::JobTemplate2023_09.as_str();
        return Err(ModelError::DecodeValidation(format!(
            "Specification version '{version_str}' is not a Job Template version. \
             Values allowed for 'specificationVersion' in Job Templates are: {allowed}"
        )));
    }

    let jt: JobTemplate = match version.revision() {
        // Future revisions may decode into a different struct layout.
        // Making the match explicit now localizes the dispatch point.
        SpecificationRevision::V2023_09 => serde_json::from_value(template).map_err(|e| {
            ModelError::DecodeValidation(format!("'{version_str}' failed checks: {e}"))
        })?,
    };

    // Build extension set with collect-all error reporting. Any problems
    // (empty list, duplicates, unsupported names) are reported through
    // `errors` with path `extensions` and aggregated messages.
    let mut errors = ValidationErrors::default();
    let extensions =
        validate_extensions_list(jt.extensions.as_deref(), supported_extensions, &mut errors);
    errors.into_result("JobTemplate")?;

    // Route to the revision-specific validation pipeline via the
    // revision-neutral dispatcher. The revision comes from the template's
    // declared `specificationVersion`, not from a hardcoded constant.
    let ctx = ValidationContext::with_extensions(version.revision(), extensions)
        .with_caller_limits(caller_limits.clone());
    validate::validate_job_template(&jt, &ctx)?;

    Ok(jt)
}

/// Decode and validate an environment template from a YAML value.
pub fn decode_environment_template(
    template: serde_json::Value,
    supported_extensions: Option<&[&str]>,
) -> Result<EnvironmentTemplate, ModelError> {
    let version_str = template
        .get("specificationVersion")
        .and_then(|v| v.as_str())
        .map(|s| s.to_string())
        .ok_or_else(|| {
            ModelError::DecodeValidation(
                "Template is missing Open Job Description schema version key: specificationVersion"
                    .to_string(),
            )
        })?;

    let version = TemplateSpecificationVersion::from_str(&version_str).map_err(|_| {
        let allowed = TemplateSpecificationVersion::Environment2023_09.as_str();
        ModelError::DecodeValidation(format!(
            "Unknown template version: {version_str}. Allowed values are: {allowed}"
        ))
    })?;

    if !version.is_environment_template() {
        let allowed = TemplateSpecificationVersion::Environment2023_09.as_str();
        return Err(ModelError::DecodeValidation(format!(
            "Specification version '{version_str}' is not an Environment Template version. \
             Allowed values for 'specificationVersion' are: {allowed}"
        )));
    }

    let et: EnvironmentTemplate = match version.revision() {
        // Future revisions may decode into a different struct layout.
        // Making the match explicit now localizes the dispatch point,
        // mirroring `decode_job_template`.
        SpecificationRevision::V2023_09 => serde_json::from_value(template).map_err(|e| {
            ModelError::DecodeValidation(format!("'{version_str}' failed checks: {e}"))
        })?,
    };

    // Build extension set with collect-all error reporting. Same helper
    // as decode_job_template; the error model name is different.
    let mut errors = ValidationErrors::default();
    let extensions =
        validate_extensions_list(et.extensions.as_deref(), supported_extensions, &mut errors);
    errors.into_result("EnvironmentTemplate")?;

    let ctx = ValidationContext::with_extensions(version.revision(), extensions);
    validate::validate_environment_template(&et, &ctx)?;

    Ok(et)
}

/// Auto-detect template type and decode.
// Both variants are large structs only used as return values, not stored in collections.
#[allow(clippy::large_enum_variant)]
#[derive(Debug)]
pub enum DecodedTemplate {
    Job(JobTemplate),
    Environment(EnvironmentTemplate),
}

/// Auto-detect whether a template is a job or environment template and decode it.
pub fn decode_template(
    template: serde_json::Value,
    supported_extensions: Option<&[&str]>,
    caller_limits: &CallerLimits,
) -> Result<DecodedTemplate, ModelError> {
    let version_str = template
        .get("specificationVersion")
        .and_then(|v| v.as_str())
        .map(|s| s.to_string())
        .ok_or_else(|| {
            ModelError::DecodeValidation(
                "Template is missing Open Job Description schema version key: specificationVersion"
                    .to_string(),
            )
        })?;

    let version = version_str
        .parse::<TemplateSpecificationVersion>()
        .map_err(|_| {
            ModelError::DecodeValidation(format!("Unknown template version: {version_str}"))
        })?;

    if version.is_job_template() {
        decode_job_template(template, supported_extensions, caller_limits).map(DecodedTemplate::Job)
    } else {
        decode_environment_template(template, supported_extensions)
            .map(DecodedTemplate::Environment)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    fn yaml_val(s: &str) -> serde_json::Value {
        serde_saphyr::from_str(s).unwrap()
    }

    // -- document_string_to_object --

    #[test]
    fn test_doc_string_to_object_json() {
        let result = document_string_to_object(
            r#"{"key": "value"}"#,
            DocumentType::Json,
            &CallerLimits::default(),
        )
        .unwrap();
        assert_eq!(result["key"].as_str().unwrap(), "value");
    }

    #[test]
    fn test_doc_string_to_object_yaml() {
        let result =
            document_string_to_object("key: value\n", DocumentType::Yaml, &CallerLimits::default())
                .unwrap();
        assert_eq!(result["key"].as_str().unwrap(), "value");
    }

    #[test]
    fn test_doc_string_not_a_dict_json() {
        assert!(document_string_to_object(
            "[1, 2, 3]",
            DocumentType::Json,
            &CallerLimits::default()
        )
        .is_err());
    }

    #[test]
    fn test_doc_string_not_a_dict_yaml() {
        assert!(document_string_to_object(
            "- 1\n- 2\n",
            DocumentType::Yaml,
            &CallerLimits::default()
        )
        .is_err());
    }

    #[test]
    fn test_doc_string_bad_parse_json() {
        assert!(
            document_string_to_object("{", DocumentType::Json, &CallerLimits::default()).is_err()
        );
    }

    #[test]
    fn test_doc_string_bad_parse_yaml() {
        assert!(
            document_string_to_object("-", DocumentType::Yaml, &CallerLimits::default()).is_err()
        );
    }

    // -- decode_job_template --

    #[test]
    fn test_decode_job_template_missing_spec_version() {
        let v = yaml_val(r#"{"notspecversion": "badvalue"}"#);
        assert!(decode_job_template(v, None, &CallerLimits::default()).is_err());
    }

    #[test]
    fn test_decode_job_template_unknown_version() {
        let v = yaml_val(r#"{"specificationVersion": "badvalue"}"#);
        assert!(decode_job_template(v, None, &CallerLimits::default()).is_err());
    }

    #[test]
    fn test_decode_job_template_not_job_version() {
        let v = yaml_val(r#"{"specificationVersion": "environment-2023-09"}"#);
        assert!(decode_job_template(v, None, &CallerLimits::default()).is_err());
    }

    #[test]
    fn test_decode_job_template_success() {
        let v = yaml_val(
            r#"{
            "specificationVersion": "jobtemplate-2023-09",
            "name": "name",
            "steps": [{"name": "step", "script": {"actions": {"onRun": {"command": "do thing"}}}}]
        }"#,
        );
        let jt = decode_job_template(v, None, &CallerLimits::default()).unwrap();
        assert_eq!(jt.specification_version, "jobtemplate-2023-09");
    }

    // -- decode_environment_template --

    #[test]
    fn test_decode_env_template_missing_spec_version() {
        let v = yaml_val(r#"{"notspecversion": "badvalue"}"#);
        assert!(decode_environment_template(v, None).is_err());
    }

    #[test]
    fn test_decode_env_template_unknown_version() {
        let v = yaml_val(r#"{"specificationVersion": "badvalue"}"#);
        assert!(decode_environment_template(v, None).is_err());
    }

    #[test]
    fn test_decode_env_template_not_env_version() {
        let v = yaml_val(r#"{"specificationVersion": "jobtemplate-2023-09"}"#);
        assert!(decode_environment_template(v, None).is_err());
    }

    #[test]
    fn test_decode_env_template_success() {
        let v = yaml_val(
            r#"{
            "specificationVersion": "environment-2023-09",
            "environment": {
                "name": "FooEnv",
                "description": "A description",
                "script": {"actions": {"onEnter": {"command": "echo", "args": ["Hello", "World"]}}}
            }
        }"#,
        );
        let et = decode_environment_template(v, None).unwrap();
        assert_eq!(et.specification_version, "environment-2023-09");
    }

    // -- decode_template (auto-detect) --

    #[test]
    fn test_decode_template_auto_detect_job() {
        let v = yaml_val(
            r#"{
            "specificationVersion": "jobtemplate-2023-09",
            "name": "name",
            "steps": [{"name": "step", "script": {"actions": {"onRun": {"command": "do thing"}}}}]
        }"#,
        );
        assert!(matches!(
            decode_template(v, None, &CallerLimits::default()).unwrap(),
            DecodedTemplate::Job(_)
        ));
    }

    #[test]
    fn test_decode_template_auto_detect_env() {
        let v = yaml_val(
            r#"{
            "specificationVersion": "environment-2023-09",
            "environment": {
                "name": "FooEnv",
                "description": "A description",
                "script": {"actions": {"onEnter": {"command": "echo", "args": ["Hello", "World"]}}}
            }
        }"#,
        );
        assert!(matches!(
            decode_template(v, None, &CallerLimits::default()).unwrap(),
            DecodedTemplate::Environment(_)
        ));
    }

    #[test]
    fn test_decode_template_missing_version() {
        let v = yaml_val(r#"{"name": "test"}"#);
        let err = decode_template(v, None, &CallerLimits::default()).unwrap_err();
        assert!(err.to_string().contains("specificationVersion"));
    }

    #[test]
    fn test_decode_template_unknown_version() {
        let v = yaml_val(r#"{"specificationVersion": "badvalue"}"#);
        let err = decode_template(v, None, &CallerLimits::default()).unwrap_err();
        assert!(err.to_string().contains("Unknown template version"));
    }

    // ══════════════════════════════════════════════════════════════
    // ══════════════════════════════════════════════════════════════
    // ModelValidation structured errors via decode_job_template
    // ══════════════════════════════════════════════════════════════
    #[test]
    fn validation_error_has_structured_paths() {
        // Step name exceeds 64 chars — triggers ModelValidation
        let long_name = "a".repeat(128);
        let v = yaml_val(&format!(
            r#"{{
            "specificationVersion": "jobtemplate-2023-09",
            "name": "test",
            "steps": [{{"name": "{long_name}", "script": {{"actions": {{"onRun": {{"command": "echo"}}}}}}}}]
        }}"#,
        ));
        let err = decode_job_template(v, None, &Default::default()).unwrap_err();
        let errors = match &err {
            crate::error::ModelError::ModelValidation(e) => e,
            other => panic!("expected ModelValidation, got: {other}"),
        };
        assert_eq!(errors.len(), 1);
        let e = &errors.errors[0];
        assert_eq!(
            e.path,
            vec![
                crate::error::PathElement::Field("steps".into()),
                crate::error::PathElement::Index(0),
                crate::error::PathElement::Field("name".into()),
            ]
        );
        assert!(
            e.message.contains("64"),
            "expected message about 64-char limit, got: {}",
            e.message
        );
        // Display output matches the Pydantic-compatible format
        assert_eq!(
            err.to_string(),
            format!(
                "Model validation error: 1 validation error for JobTemplate\nsteps[0] -> name:\n\t{}",
                e.message
            )
        );
    }

    #[test]
    fn validation_error_paths_contain_steps() {
        // Missing 'script' — step has no actions
        let v = yaml_val(
            r#"{
            "specificationVersion": "jobtemplate-2023-09",
            "name": "test",
            "steps": [{"name": "s"}]
        }"#,
        );
        let err = decode_job_template(v, None, &Default::default()).unwrap_err();
        let errors = match &err {
            crate::error::ModelError::ModelValidation(e) => e,
            other => panic!("expected ModelValidation, got: {other}"),
        };
        assert!(!errors.is_empty());
        // Every error should reference steps[0]
        for e in &errors.errors {
            assert!(
                e.path.len() >= 2,
                "expected path with at least 2 elements, got: {:?}",
                e.path
            );
            assert_eq!(e.path[0], crate::error::PathElement::Field("steps".into()),);
            assert_eq!(e.path[1], crate::error::PathElement::Index(0),);
        }
    }
}