taudit-parse-gitlab 1.0.10

use std::collections::HashMap;

use serde::{Deserialize, Serialize};
use serde_yaml::Value;
use taudit_core::error::TauditError;
use taudit_core::graph::*;
// Re-import explicitly to make the new constants visible at a glance.
#[allow(unused_imports)]
use taudit_core::graph::{META_DOTENV_FILE, META_ENVIRONMENT_NAME, META_NEEDS, META_SCRIPT_BODY};
use taudit_core::ports::PipelineParser;

/// GitLab CI YAML parser.
///
/// Parses `.gitlab-ci.yml` files into an `AuthorityGraph`. The authority model:
/// - Each job is a `Step` node.
/// - `CI_JOB_TOKEN` is a global implicit `Identity` (always present, scope=broad).
/// - `secrets:` entries emit `Secret` nodes with `HasAccessTo` edges.
/// - `id_tokens:` entries emit OIDC `Identity` nodes.
/// - `variables:` entries with credential-pattern names emit `Secret` nodes.
/// - `image:` and `services:` emit `Image` nodes with `UsesImage` edges.
/// - `include:` and `extends:` mark the graph `Partial`.
/// - `rules: if: merge_request_event` and `only: merge_requests` set `META_TRIGGER`.
pub struct GitlabParser;

/// Reserved top-level keys that are not job definitions.
const RESERVED: &[&str] = &[
    "stages",
    "workflow",
    "include",
    "variables",
    "image",
    "services",
    "default",
    "cache",
    "before_script",
    "after_script",
    "types",
];

/// Variable name fragments that indicate a credential rather than plain config.
const CRED_FRAGMENTS: &[&str] = &[
    "TOKEN",
    "SECRET",
    "PASSWORD",
    "PASSWD",
    "PRIVATE_KEY",
    "API_KEY",
    "APIKEY",
    "SIGNING_KEY",
    "ACCESS_KEY",
    "SERVICE_ACCOUNT",
    "CERT",
    "CREDENTIAL",
];

impl PipelineParser for GitlabParser {
    fn platform(&self) -> &str {
        "gitlab-ci"
    }

    fn parse(&self, content: &str, source: &PipelineSource) -> Result<AuthorityGraph, TauditError> {
        let mut de = serde_yaml::Deserializer::from_str(content);
        let doc = de
            .next()
            .ok_or_else(|| TauditError::Parse("empty YAML document".into()))?;
        let root: Value = Value::deserialize(doc)
            .map_err(|e| TauditError::Parse(format!("YAML parse error: {e}")))?;

        let mapping = root
            .as_mapping()
            .ok_or_else(|| TauditError::Parse("GitLab CI root must be a mapping".into()))?;

        let mut graph = AuthorityGraph::new(source.clone());
        graph.metadata.insert(META_PLATFORM.into(), "gitlab".into());

        // CI_JOB_TOKEN is always present in every GitLab CI job — it's the built-in
        // platform token, equivalent to ADO's System.AccessToken or GHA's GITHUB_TOKEN.
        let mut meta = HashMap::new();
        meta.insert(META_IDENTITY_SCOPE.into(), "broad".into());
        meta.insert(META_IMPLICIT.into(), "true".into());
        let token_id = graph.add_node_with_metadata(
            NodeKind::Identity,
            "CI_JOB_TOKEN",
            TrustZone::FirstParty,
            meta,
        );

        // Top-level include: → mark Partial immediately AND capture each
        // entry's structure as graph metadata so include-pinning rules can
        // reason about remote URLs and unpinned project refs.
        if let Some(inc) = mapping.get("include") {
            graph.mark_partial(
                GapKind::Structural,
                "include: directive present — included templates not resolved".to_string(),
            );
            let entries = extract_include_entries(inc);
            if !entries.is_empty() {
                if let Ok(json) = serde_json::to_string(&entries) {
                    graph.metadata.insert(META_GITLAB_INCLUDES.into(), json);
                }
            }
        }

        // Global variables
        let global_secrets = process_variables(mapping.get("variables"), &mut graph, "pipeline");

        // Global image
        let global_image = mapping.get("image").and_then(extract_image_str);

        // Top-level merge_request trigger detection from `workflow:` rules
        if let Some(wf) = mapping.get("workflow") {
            if has_mr_trigger_in_workflow(wf) {
                graph
                    .metadata
                    .insert(META_TRIGGER.into(), "merge_request".into());
            }
        }

        // Process each job (any top-level key not in RESERVED)
        for (key, value) in mapping {
            let job_name = match key.as_str() {
                Some(k) => k,
                None => continue,
            };
            if RESERVED.contains(&job_name) {
                continue;
            }

            // Hidden jobs (starting with a dot) are templates — mark Partial, skip
            if job_name.starts_with('.') {
                graph.mark_partial(
                    GapKind::Structural,
                    format!("job '{job_name}' is a hidden/template job — not resolved"),
                );
                continue;
            }

            let job_map = match value.as_mapping() {
                Some(m) => m,
                None => continue,
            };

            // extends: — job template inheritance, can't resolve statically
            let extends_names = extract_extends_list(job_map.get("extends"));
            if !extends_names.is_empty() {
                graph.mark_partial(
                    GapKind::Structural,
                    format!(
                        "job '{job_name}' uses extends: — inherited configuration not resolved"
                    ),
                );
            }

            // Detect PR/MR trigger in this job's rules: or only:
            let job_triggers_mr = job_has_mr_trigger(job_map);

            // Propagate job MR trigger to graph level
            if job_triggers_mr && !graph.metadata.contains_key(META_TRIGGER) {
                graph
                    .metadata
                    .insert(META_TRIGGER.into(), "merge_request".into());
            }

            // Job-level variables
            let job_secrets = process_variables(job_map.get("variables"), &mut graph, job_name);

            // Job-level explicit secrets: (Vault, AWS Secrets Manager, GCP, Azure)
            let explicit_secrets =
                process_explicit_secrets(job_map.get("secrets"), job_name, &mut graph);

            // Job-level OIDC tokens (id_tokens:)
            let oidc_identities = process_id_tokens(job_map.get("id_tokens"), job_name, &mut graph);

            // Job image (falls back to global)
            let job_image_str = job_map
                .get("image")
                .and_then(extract_image_str)
                .or(global_image.as_deref().map(String::from));

            let image_id = job_image_str.as_deref().map(|img| {
                let pinned = is_docker_digest_pinned(img);
                let trust_zone = if pinned {
                    TrustZone::ThirdParty
                } else {
                    TrustZone::Untrusted
                };
                let mut imeta = HashMap::new();
                if let Some(digest) = img.split("@sha256:").nth(1) {
                    imeta.insert(META_DIGEST.into(), format!("sha256:{digest}"));
                }
                graph.add_node_with_metadata(NodeKind::Image, img, trust_zone, imeta)
            });

            // Services (each is an Image node)
            let service_ids = process_services(job_map.get("services"), &mut graph);

            // Environment — record name as metadata, sets trust boundary marker
            let env_name = job_map
                .get("environment")
                .and_then(extract_environment_name);
            let env_url = job_map.get("environment").and_then(extract_environment_url);

            // Concatenated script body (before_script + script + after_script).
            // Stamped on the Step node so script-aware rules (notably
            // `untrusted_ci_var_in_shell_interpolation` and
            // `ci_job_token_to_external_api`) can pattern-match without
            // re-walking the YAML.
            // Inline script body — concatenate before_script, script, after_script
            // (each may be a string or a list-of-strings). Stamped on the Step so
            // script-aware rules can pattern-match without re-parsing YAML.
            let script_body = extract_script_body(job_map);

            // GitLab `artifacts.reports.dotenv: <file>` — when set, the file's
            // KEY=value lines are silently promoted to pipeline variables for
            // any downstream job that consumes this one via `needs:` /
            // `dependencies:`. Required input to
            // `dotenv_artifact_flows_to_privileged_deployment`.
            let dotenv_file = extract_dotenv_file(job_map);

            // Upstream job names consumed via `needs:` / `dependencies:`.
            // Used to build dotenv-flow chains across stages.
            let needs = extract_needs(job_map);

            // Detect whether this job's `rules:` / `only:` clause restricts
            // execution to protected branches (or to the default branch,
            // which is protected by GitLab default policy). Used by the
            // `gitlab_deploy_job_missing_protected_branch_only` rule to
            // detect deployment jobs that lack any branch guard.
            let protected_only = job_has_protected_branch_restriction(job_map);

            // Create the Step node for this job
            let mut step_meta = HashMap::new();
            step_meta.insert(META_JOB_NAME.into(), job_name.to_string());
            if let Some(ref env) = env_name {
                step_meta.insert(META_ENVIRONMENT_NAME.into(), env.clone());
            }
            if !script_body.is_empty() {
                step_meta.insert(META_SCRIPT_BODY.into(), script_body);
            }
            if let Some(ref f) = dotenv_file {
                step_meta.insert(META_DOTENV_FILE.into(), f.clone());
            }
            if !needs.is_empty() {
                step_meta.insert(META_NEEDS.into(), needs.join(","));
            }
            if let Some(ref url) = env_url {
                step_meta.insert(META_ENVIRONMENT_URL.into(), url.clone());
            }
            // Per-step MR trigger marker — graph-level META_TRIGGER applies to
            // the file as a whole, but `id_token_audience_overscoped` needs to
            // compare audience usage between MR-context and protected-context
            // jobs in the same file.
            if job_triggers_mr {
                step_meta.insert(META_TRIGGER.into(), "merge_request".into());
            }
            // extends: list (comma-joined, in source order)
            if !extends_names.is_empty() {
                step_meta.insert(META_GITLAB_EXTENDS.into(), extends_names.join(","));
            }
            // allow_failure: true|false (only stamp when explicitly set so the
            // rule can distinguish "absent" from "false")
            if let Some(af) = job_map.get("allow_failure").and_then(|v| v.as_bool()) {
                step_meta.insert(META_GITLAB_ALLOW_FAILURE.into(), af.to_string());
            } else if job_map
                .get("allow_failure")
                .and_then(|v| v.as_mapping())
                .is_some()
            {
                // `allow_failure: { exit_codes: [42] }` — conditional pass; treat
                // as truthy for silent-skip detection.
                step_meta.insert(META_GITLAB_ALLOW_FAILURE.into(), "true".into());
            }
            // dind sidecar detection: any service whose name matches docker:*-dind
            if job_services_have_dind(job_map.get("services")) {
                step_meta.insert(META_GITLAB_DIND_SERVICE.into(), "true".into());
            }
            // trigger: block — child / downstream pipeline
            if let Some(kind) = classify_trigger(job_map.get("trigger")) {
                step_meta.insert(META_GITLAB_TRIGGER_KIND.into(), kind.into());
            }
            // cache: structural capture (key + policy)
            if let Some((cache_key, cache_policy)) = extract_cache_key_policy(job_map.get("cache"))
            {
                step_meta.insert(META_GITLAB_CACHE_KEY.into(), cache_key);
                if let Some(p) = cache_policy {
                    step_meta.insert(META_GITLAB_CACHE_POLICY.into(), p);
                }
            }
            if protected_only {
                step_meta.insert(META_RULES_PROTECTED_ONLY.into(), "true".into());
            }
            let step_id = graph.add_node_with_metadata(
                NodeKind::Step,
                job_name,
                TrustZone::FirstParty,
                step_meta,
            );

            // CI_JOB_TOKEN always available to every step
            graph.add_edge(step_id, token_id, EdgeKind::HasAccessTo);

            // Link all secrets
            for &sid in global_secrets
                .iter()
                .chain(&job_secrets)
                .chain(&explicit_secrets)
            {
                graph.add_edge(step_id, sid, EdgeKind::HasAccessTo);
            }

            // Link OIDC identities
            for &iid in &oidc_identities {
                graph.add_edge(step_id, iid, EdgeKind::HasAccessTo);
            }

            // UsesImage edges
            if let Some(img_id) = image_id {
                graph.add_edge(step_id, img_id, EdgeKind::UsesImage);
            }
            for &svc_id in &service_ids {
                graph.add_edge(step_id, svc_id, EdgeKind::UsesImage);
            }
        }

        // Cross-platform misclassification trap (red-team R2 #5): a YAML file
        // with non-reserved top-level keys looks like a GitLab pipeline shape
        // but its body may use constructs the GitLab parser doesn't recognise
        // (e.g. an ADO `task:` payload). Mark Partial when the source had at
        // least one job-shaped top-level key but we ended up with no Step
        // nodes — better than silently returning completeness=complete on a
        // clean-but-empty graph that a CI gate would treat as "passed".
        let step_count = graph
            .nodes
            .iter()
            .filter(|n| n.kind == NodeKind::Step)
            .count();
        let had_job_carrier = mapping.iter().any(|(k, v)| {
            k.as_str()
                .map(|name| !RESERVED.contains(&name) && !name.starts_with('.'))
                .unwrap_or(false)
                && v.as_mapping().is_some()
        });
        if step_count == 0 && had_job_carrier {
            graph.mark_partial(
                GapKind::Opaque,
                "non-reserved top-level keys parsed but produced 0 step nodes — possible non-GitLab YAML wrong-platform-classified".to_string(),
            );
        }

        graph.stamp_edge_authority_summaries();
        Ok(graph)
    }
}

/// Detect `image:` string from a YAML value — can be a bare string or a mapping with `name:`.
fn extract_image_str(v: &Value) -> Option<String> {
    match v {
        Value::String(s) => Some(s.clone()),
        Value::Mapping(m) => m.get("name").and_then(|n| n.as_str()).map(String::from),
        _ => None,
    }
}

/// Extract environment name from `environment:` value (string or mapping).
fn extract_environment_name(v: &Value) -> Option<String> {
    match v {
        Value::String(s) => Some(s.clone()),
        Value::Mapping(m) => m.get("name").and_then(|n| n.as_str()).map(String::from),
        _ => None,
    }
}

/// Extract `environment:url:` value (only present when environment is a mapping).
fn extract_environment_url(v: &Value) -> Option<String> {
    match v {
        Value::Mapping(m) => m.get("url").and_then(|u| u.as_str()).map(String::from),
        _ => None,
    }
}

/// Concatenate `before_script`, `script`, and `after_script` of a job into one
/// string body (separated by newlines). Each section may be a single string or
/// a list of strings. Empty sections are skipped.
fn extract_script_body(job_map: &serde_yaml::Mapping) -> String {
    let mut lines: Vec<String> = Vec::new();
    for key in &["before_script", "script", "after_script"] {
        if let Some(v) = job_map.get(*key) {
            collect_script_lines(v, &mut lines);
        }
    }
    lines.join("\n")
}

/// Append script lines from a YAML value (string or sequence of strings).
fn collect_script_lines(v: &Value, out: &mut Vec<String>) {
    match v {
        Value::String(s) => out.push(s.clone()),
        Value::Sequence(seq) => {
            for item in seq {
                if let Some(s) = item.as_str() {
                    out.push(s.to_string());
                }
            }
        }
        _ => {}
    }
}

/// Extract `artifacts.reports.dotenv` filename. Value may be a single string
/// or a list of strings — for the list form we join with `,`.
fn extract_dotenv_file(job_map: &serde_yaml::Mapping) -> Option<String> {
    let dotenv = job_map
        .get("artifacts")?
        .as_mapping()?
        .get("reports")?
        .as_mapping()?
        .get("dotenv")?;
    match dotenv {
        Value::String(s) => Some(s.clone()),
        Value::Sequence(seq) => {
            let parts: Vec<String> = seq
                .iter()
                .filter_map(|v| v.as_str().map(String::from))
                .collect();
            if parts.is_empty() {
                None
            } else {
                Some(parts.join(","))
            }
        }
        _ => None,
    }
}

/// Extract upstream job names from `needs:` and `dependencies:`.
/// `needs:` may be a list of strings or a list of mappings with `job:`.
/// `dependencies:` is a list of strings.
fn extract_needs(job_map: &serde_yaml::Mapping) -> Vec<String> {
    let mut out: Vec<String> = Vec::new();
    if let Some(needs) = job_map.get("needs").and_then(|v| v.as_sequence()) {
        for item in needs {
            match item {
                Value::String(s) => out.push(s.clone()),
                Value::Mapping(m) => {
                    if let Some(j) = m.get("job").and_then(|j| j.as_str()) {
                        out.push(j.to_string());
                    }
                }
                _ => {}
            }
        }
    }
    if let Some(deps) = job_map.get("dependencies").and_then(|v| v.as_sequence()) {
        for item in deps {
            if let Some(s) = item.as_str() {
                out.push(s.to_string());
            }
        }
    }
    out.sort();
    out.dedup();
    out
}

/// Classify a variable name as a credential by checking for common fragments.
fn is_credential_name(name: &str) -> bool {
    let upper = name.to_uppercase();
    CRED_FRAGMENTS.iter().any(|frag| upper.contains(frag))
}

/// Parse `variables:` mapping and emit `Secret` nodes for credential-pattern names.
/// Returns the list of created node IDs.
fn process_variables(vars: Option<&Value>, graph: &mut AuthorityGraph, scope: &str) -> Vec<NodeId> {
    let mut ids = Vec::new();
    let map = match vars.and_then(|v| v.as_mapping()) {
        Some(m) => m,
        None => return ids,
    };
    for (k, _v) in map {
        let name = match k.as_str() {
            Some(s) => s,
            None => continue,
        };
        if is_credential_name(name) {
            let id = graph.add_node(NodeKind::Secret, name, TrustZone::FirstParty);
            ids.push(id);
            let _ = scope; // used for future scoped error messages
        }
    }
    ids
}

/// Parse `secrets:` block and emit one `Secret` node per named secret.
///
/// GitLab CI `secrets:` format:
/// ```yaml
/// secrets:
///   DATABASE_PASSWORD:
///     vault: production/db/password@secret
///   AWS_KEY:
///     aws_secrets_manager:
///       name: my-secret
/// ```
fn process_explicit_secrets(
    secrets: Option<&Value>,
    _scope: &str,
    graph: &mut AuthorityGraph,
) -> Vec<NodeId> {
    let mut ids = Vec::new();
    let map = match secrets.and_then(|v| v.as_mapping()) {
        Some(m) => m,
        None => return ids,
    };
    for (k, _v) in map {
        let name = match k.as_str() {
            Some(s) => s,
            None => continue,
        };
        let id = graph.add_node(NodeKind::Secret, name, TrustZone::FirstParty);
        ids.push(id);
    }
    ids
}

/// Parse `id_tokens:` block and emit one OIDC `Identity` node per token.
///
/// GitLab CI `id_tokens:` format:
/// ```yaml
/// id_tokens:
///   SIGSTORE_ID_TOKEN:
///     aud: sigstore
///   AWS_OIDC_TOKEN:
///     aud: https://sts.amazonaws.com
/// ```
fn process_id_tokens(
    id_tokens: Option<&Value>,
    _scope: &str,
    graph: &mut AuthorityGraph,
) -> Vec<NodeId> {
    let mut ids = Vec::new();
    let map = match id_tokens.and_then(|v| v.as_mapping()) {
        Some(m) => m,
        None => return ids,
    };
    for (k, v) in map {
        let token_name = match k.as_str() {
            Some(s) => s,
            None => continue,
        };
        // Extract audience for labelling and as discrete metadata
        // (rules like `id_token_audience_overscoped` need to compare audiences
        // across jobs without re-parsing the label).
        let aud = v
            .as_mapping()
            .and_then(|m| m.get("aud"))
            .and_then(|a| a.as_str())
            .unwrap_or("unknown");
        let label = format!("{token_name} (aud={aud})");
        let mut meta = HashMap::new();
        meta.insert(META_OIDC.into(), "true".into());
        meta.insert(META_IDENTITY_SCOPE.into(), "broad".into());
        meta.insert(META_OIDC_AUDIENCE.into(), aud.to_string());
        let id =
            graph.add_node_with_metadata(NodeKind::Identity, label, TrustZone::FirstParty, meta);
        ids.push(id);
    }
    ids
}

/// Parse `services:` block and emit `Image` nodes.
fn process_services(services: Option<&Value>, graph: &mut AuthorityGraph) -> Vec<NodeId> {
    let mut ids = Vec::new();
    let list = match services.and_then(|v| v.as_sequence()) {
        Some(s) => s,
        None => return ids,
    };
    for item in list {
        let img_str = match extract_image_str(item) {
            Some(s) => s,
            None => continue,
        };
        let pinned = is_docker_digest_pinned(&img_str);
        let trust_zone = if pinned {
            TrustZone::ThirdParty
        } else {
            TrustZone::Untrusted
        };
        let mut meta = HashMap::new();
        if let Some(digest) = img_str.split("@sha256:").nth(1) {
            meta.insert(META_DIGEST.into(), format!("sha256:{digest}"));
        }
        let id = graph.add_node_with_metadata(NodeKind::Image, &img_str, trust_zone, meta);
        ids.push(id);
    }
    ids
}

/// Check whether a job's `rules:` or `only:` indicates it runs on merge requests.
fn job_has_mr_trigger(job_map: &serde_yaml::Mapping) -> bool {
    // rules: [{if: '$CI_PIPELINE_SOURCE == "merge_request_event"'}]
    if let Some(rules) = job_map.get("rules").and_then(|v| v.as_sequence()) {
        for rule in rules {
            if let Some(if_expr) = rule
                .as_mapping()
                .and_then(|m| m.get("if"))
                .and_then(|v| v.as_str())
            {
                if if_expr.contains("merge_request_event") {
                    return true;
                }
            }
        }
    }
    // only: [merge_requests] or only: {refs: [merge_requests]}
    if let Some(only) = job_map.get("only") {
        if only_has_merge_requests(only) {
            return true;
        }
    }
    false
}

/// Check `only:` value (sequence or mapping) for `merge_requests` entry.
fn only_has_merge_requests(v: &Value) -> bool {
    match v {
        Value::Sequence(seq) => seq
            .iter()
            .any(|item| item.as_str() == Some("merge_requests")),
        Value::Mapping(m) => {
            if let Some(refs) = m.get("refs").and_then(|r| r.as_sequence()) {
                return refs
                    .iter()
                    .any(|item| item.as_str() == Some("merge_requests"));
            }
            false
        }
        _ => false,
    }
}

/// Returns true when a job's `rules:` or `only:` clause restricts execution
/// to protected refs only. The set of accepted patterns is intentionally
/// generous because the goal is to *credit* defensive intent, not to
/// audit-grade verify that every protection actually exists in GitLab's
/// branch-protection settings — that lives outside the YAML.
///
/// Patterns recognised as a protected-only restriction:
///
///   * any `rules: [{ if: ... $CI_COMMIT_REF_PROTECTED ... }]`
///   * any `rules: [{ if: ... $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH ... }]`
///     (default branch is GitLab-protected by default)
///   * any `rules: [{ if: ... $CI_COMMIT_TAG ... }]` (tags are protected by default)
///   * `only: [main]` / `only: [master]` / `only: tags`
///   * `only: { refs: [main, /^release/.*/] }`
///
/// Hits any one of the above → true. Misses every one → false.
fn job_has_protected_branch_restriction(job_map: &serde_yaml::Mapping) -> bool {
    if let Some(rules) = job_map.get("rules").and_then(|v| v.as_sequence()) {
        for rule in rules {
            let Some(if_expr) = rule
                .as_mapping()
                .and_then(|m| m.get("if"))
                .and_then(|v| v.as_str())
            else {
                continue;
            };
            if if_expr.contains("$CI_COMMIT_REF_PROTECTED")
                || if_expr.contains("CI_COMMIT_REF_PROTECTED")
            {
                return true;
            }
            if if_expr.contains("$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH")
                || if_expr.contains("$CI_DEFAULT_BRANCH == $CI_COMMIT_BRANCH")
            {
                return true;
            }
            if if_expr.contains("$CI_COMMIT_TAG") {
                return true;
            }
        }
    }
    if let Some(only) = job_map.get("only") {
        if only_lists_protected_ref(only) {
            return true;
        }
    }
    false
}

/// Check `only:` for protected/default-branch refs (`main`, `master`, `tags`,
/// or a `refs:` list containing those). Conservative — does NOT include
/// `merge_requests` (that's the opposite signal).
fn only_lists_protected_ref(v: &Value) -> bool {
    fn is_protected_ref(s: &str) -> bool {
        matches!(s, "main" | "master" | "tags") || s.starts_with("/^release")
    }
    match v {
        Value::String(s) => is_protected_ref(s.as_str()),
        Value::Sequence(seq) => seq
            .iter()
            .any(|item| item.as_str().map(is_protected_ref).unwrap_or(false)),
        Value::Mapping(m) => {
            if let Some(refs) = m.get("refs").and_then(|r| r.as_sequence()) {
                return refs
                    .iter()
                    .any(|item| item.as_str().map(is_protected_ref).unwrap_or(false));
            }
            false
        }
        _ => false,
    }
}

/// Check top-level `workflow:` rules for MR trigger.
fn has_mr_trigger_in_workflow(wf: &Value) -> bool {
    let rules = match wf
        .as_mapping()
        .and_then(|m| m.get("rules"))
        .and_then(|r| r.as_sequence())
    {
        Some(r) => r,
        None => return false,
    };
    for rule in rules {
        if let Some(if_expr) = rule
            .as_mapping()
            .and_then(|m| m.get("if"))
            .and_then(|v| v.as_str())
        {
            if if_expr.contains("merge_request_event") {
                return true;
            }
        }
    }
    false
}

/// Structured representation of a single `include:` entry.
///
/// Serialised into `AuthorityGraph::metadata[META_GITLAB_INCLUDES]` so that
/// downstream rules (e.g. `unpinned_include_remote_or_branch_ref`) can analyse
/// remote-URL pins, project refs, and missing `ref:` defaults without re-parsing
/// the YAML.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct IncludeEntry {
    /// Include kind: `local`, `remote`, `template`, `project`, `component`, or
    /// `unknown` for shapes we don't recognise.
    pub kind: String,
    /// The path / URL / project string the include points at.
    pub target: String,
    /// The resolved `ref:` value. Empty string when the include omits a `ref:`
    /// (defaults to HEAD on the source repo, which is itself a finding).
    pub git_ref: String,
}

/// Parse the top-level `include:` value into a flat list of `IncludeEntry`s.
///
/// `include:` accepts five shapes — string, sequence-of-strings, sequence-of-mappings,
/// sequence-of-strings-mixed-with-mappings, and a single mapping. Normalise all of
/// them into one flat list so the rule layer doesn't have to.
pub fn extract_include_entries(v: &Value) -> Vec<IncludeEntry> {
    let mut out = Vec::new();
    match v {
        // `include: 'path/to/local.yml'` — sugar for a local include
        Value::String(s) => {
            out.push(IncludeEntry {
                kind: classify_string_include(s).into(),
                target: s.clone(),
                git_ref: String::new(),
            });
        }
        Value::Sequence(seq) => {
            for item in seq {
                match item {
                    Value::String(s) => {
                        out.push(IncludeEntry {
                            kind: classify_string_include(s).into(),
                            target: s.clone(),
                            git_ref: String::new(),
                        });
                    }
                    Value::Mapping(m) => {
                        if let Some(e) = include_entry_from_mapping(m) {
                            out.push(e);
                        }
                    }
                    _ => {}
                }
            }
        }
        Value::Mapping(m) => {
            if let Some(e) = include_entry_from_mapping(m) {
                out.push(e);
            }
        }
        _ => {}
    }
    out
}

/// Heuristic: a top-level `include:` string that looks like an HTTPS URL is a
/// `remote:` include in shorthand form; everything else is a `local:` path.
fn classify_string_include(s: &str) -> &'static str {
    let lower = s.to_ascii_lowercase();
    if lower.starts_with("http://") || lower.starts_with("https://") {
        "remote"
    } else {
        "local"
    }
}

/// Lift one of the four mapping forms (`local:`, `remote:`, `template:`,
/// `project:`, `component:`) into an `IncludeEntry`. Returns None when the
/// mapping has none of the recognised keys.
fn include_entry_from_mapping(m: &serde_yaml::Mapping) -> Option<IncludeEntry> {
    let str_at = |key: &str| {
        m.get(key)
            .and_then(|v| v.as_str())
            .map(str::to_string)
            .unwrap_or_default()
    };
    if let Some(s) = m.get("local").and_then(|v| v.as_str()) {
        return Some(IncludeEntry {
            kind: "local".into(),
            target: s.to_string(),
            git_ref: String::new(),
        });
    }
    if let Some(s) = m.get("remote").and_then(|v| v.as_str()) {
        return Some(IncludeEntry {
            kind: "remote".into(),
            target: s.to_string(),
            git_ref: String::new(),
        });
    }
    if let Some(s) = m.get("template").and_then(|v| v.as_str()) {
        return Some(IncludeEntry {
            kind: "template".into(),
            target: s.to_string(),
            git_ref: String::new(),
        });
    }
    if let Some(s) = m.get("component").and_then(|v| v.as_str()) {
        // GitLab CI/CD components: source@version → version is the pin
        let (target, git_ref) = match s.rsplit_once('@') {
            Some((path, ver)) => (path.to_string(), ver.to_string()),
            None => (s.to_string(), String::new()),
        };
        return Some(IncludeEntry {
            kind: "component".into(),
            target,
            git_ref,
        });
    }
    if m.contains_key("project") {
        let project = str_at("project");
        // ref: may be missing → empty string indicates HEAD/default branch,
        // which is itself a supply-chain finding.
        let git_ref = str_at("ref");
        return Some(IncludeEntry {
            kind: "project".into(),
            target: project,
            git_ref,
        });
    }
    None
}

/// Extract a flat list of template names from an `extends:` value.
/// `extends:` accepts a single string or a sequence of strings.
fn extract_extends_list(v: Option<&Value>) -> Vec<String> {
    let v = match v {
        Some(v) => v,
        None => return Vec::new(),
    };
    match v {
        Value::String(s) => vec![s.clone()],
        Value::Sequence(seq) => seq
            .iter()
            .filter_map(|i| i.as_str().map(str::to_string))
            .collect(),
        _ => Vec::new(),
    }
}

/// Returns true when any entry in `services:` has an image name matching
/// `docker:*-dind` (or bare `docker:dind`). Recognises both shapes:
/// `services: [docker:dind]` and `services: [{name: docker:dind}]`.
fn job_services_have_dind(services: Option<&Value>) -> bool {
    let list = match services.and_then(|v| v.as_sequence()) {
        Some(s) => s,
        None => return false,
    };
    for item in list {
        let img = match extract_image_str(item) {
            Some(s) => s,
            None => continue,
        };
        if image_is_dind(&img) {
            return true;
        }
    }
    false
}

/// Match `docker:dind`, `docker:24.0-dind`, `docker:24-dind`,
/// `docker:24.0.7-dind-rootless`, etc. The discriminator is a `docker:` prefix
/// AND `dind` appearing somewhere in the tag.
fn image_is_dind(image: &str) -> bool {
    let lower = image.to_ascii_lowercase();
    // Match the official docker dind images and their digest-pinned variants.
    // Strip any `@sha256:...` suffix before checking the tag.
    let bare = match lower.split_once('@') {
        Some((b, _)) => b,
        None => &lower,
    };
    if !bare.starts_with("docker:") && !bare.starts_with("docker/") {
        return false;
    }
    bare.contains("dind")
}

/// Classify a `trigger:` block as either `static` (in-tree YAML / fixed
/// downstream project) or `dynamic` (include from a previous job's artifact —
/// dynamic child pipelines, the code-injection sink). Returns None when no
/// `trigger:` block is present.
fn classify_trigger(trigger: Option<&Value>) -> Option<&'static str> {
    let t = trigger?;
    // Shorthand: `trigger: my/downstream/project` → static
    if t.is_string() {
        return Some("static");
    }
    let m = t.as_mapping()?;
    // Look at every `include:` entry under trigger; if ANY one references an
    // `artifact:` field, the child pipeline is dynamic.
    if let Some(inc) = m.get("include") {
        if include_has_artifact_source(inc) {
            return Some("dynamic");
        }
    }
    Some("static")
}

/// Walk a `trigger.include:` value (string / sequence / mapping) and return
/// true when any entry's mapping carries an `artifact:` key.
fn include_has_artifact_source(v: &Value) -> bool {
    match v {
        Value::Mapping(m) => m.contains_key("artifact"),
        Value::Sequence(seq) => seq.iter().any(|i| {
            i.as_mapping()
                .map(|m| m.contains_key("artifact"))
                .unwrap_or(false)
        }),
        _ => false,
    }
}

/// Extract `(cache.key, cache.policy)` from a job's `cache:` value. Returns
/// `None` when no cache is declared. `cache:` may be a sequence of mappings
/// (multiple caches); we capture the first key/policy pair so the rule layer
/// has at least one signal — multi-cache analysis is left to a future
/// extension.
///
/// `cache.key:` may be:
/// - a string: `key: vendor`
/// - a mapping: `key: { files: [Gemfile.lock] }` → captured as `files:Gemfile.lock,...`
/// - a mapping with `prefix:` → captured as `prefix:<value>`
fn extract_cache_key_policy(v: Option<&Value>) -> Option<(String, Option<String>)> {
    let v = v?;
    let m = match v {
        Value::Mapping(m) => m,
        Value::Sequence(seq) => {
            // First cache wins — same heuristic used elsewhere.
            return seq
                .iter()
                .find_map(|i| i.as_mapping().and_then(extract_cache_key_policy_map));
        }
        _ => return None,
    };
    extract_cache_key_policy_map(m)
}

fn extract_cache_key_policy_map(m: &serde_yaml::Mapping) -> Option<(String, Option<String>)> {
    let key = match m.get("key") {
        Some(Value::String(s)) => s.clone(),
        Some(Value::Number(n)) => n.to_string(),
        Some(Value::Bool(b)) => b.to_string(),
        Some(Value::Mapping(km)) => {
            let mut parts = Vec::new();
            if let Some(prefix) = km.get("prefix").and_then(|v| v.as_str()) {
                parts.push(format!("prefix:{prefix}"));
            }
            if let Some(files) = km.get("files").and_then(|v| v.as_sequence()) {
                let names: Vec<String> = files
                    .iter()
                    .filter_map(|f| f.as_str().map(str::to_string))
                    .collect();
                if !names.is_empty() {
                    parts.push(format!("files:{}", names.join(",")));
                }
            }
            if parts.is_empty() {
                String::new()
            } else {
                parts.join(";")
            }
        }
        _ => String::new(),
    };
    let policy = m.get("policy").and_then(|v| v.as_str()).map(str::to_string);
    Some((key, policy))
}

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

    fn parse(yaml: &str) -> AuthorityGraph {
        let parser = GitlabParser;
        let source = PipelineSource {
            file: ".gitlab-ci.yml".into(),
            repo: None,
            git_ref: None,
            commit_sha: None,
        };
        parser.parse(yaml, &source).unwrap()
    }

    #[test]
    fn ci_job_token_always_present() {
        let yaml = r#"
stages:
  - build

build-job:
  stage: build
  script:
    - make build
"#;
        let graph = parse(yaml);
        let identities: Vec<_> = graph.nodes_of_kind(NodeKind::Identity).collect();
        assert_eq!(identities.len(), 1);
        assert_eq!(identities[0].name, "CI_JOB_TOKEN");
        assert_eq!(
            identities[0]
                .metadata
                .get(META_IMPLICIT)
                .map(String::as_str),
            Some("true")
        );
        assert_eq!(
            identities[0]
                .metadata
                .get(META_IDENTITY_SCOPE)
                .map(String::as_str),
            Some("broad")
        );
    }

    #[test]
    fn global_credential_variable_emits_secret_node() {
        let yaml = r#"
variables:
  APP_VERSION: "1.0"
  DEPLOY_TOKEN: "$CI_DEPLOY_TOKEN"

build-job:
  script:
    - make
"#;
        let graph = parse(yaml);
        let secrets: Vec<_> = graph.nodes_of_kind(NodeKind::Secret).collect();
        assert!(
            secrets.iter().any(|s| s.name == "DEPLOY_TOKEN"),
            "DEPLOY_TOKEN must emit a Secret node, got: {:?}",
            secrets.iter().map(|s| &s.name).collect::<Vec<_>>()
        );
        // Plain config variable must not emit Secret
        assert!(
            !secrets.iter().any(|s| s.name == "APP_VERSION"),
            "APP_VERSION must not emit a Secret node"
        );
    }

    #[test]
    fn floating_image_emits_untrusted_image_node() {
        let yaml = r#"
deploy:
  image: alpine:latest
  script:
    - deploy.sh
"#;
        let graph = parse(yaml);
        let images: Vec<_> = graph.nodes_of_kind(NodeKind::Image).collect();
        assert_eq!(images.len(), 1);
        assert_eq!(images[0].name, "alpine:latest");
        assert_eq!(images[0].trust_zone, TrustZone::Untrusted);
    }

    #[test]
    fn digest_pinned_image_is_third_party() {
        let yaml = r#"
deploy:
  image: "alpine@sha256:a5ac7e51b41094c92402da3b24376905380afc29a5ac7e51b41094c92402da3b"
  script:
    - deploy.sh
"#;
        let graph = parse(yaml);
        let images: Vec<_> = graph.nodes_of_kind(NodeKind::Image).collect();
        assert_eq!(images.len(), 1);
        assert_eq!(images[0].trust_zone, TrustZone::ThirdParty);
    }

    #[test]
    fn id_tokens_emit_oidc_identity_nodes() {
        let yaml = r#"
deploy:
  id_tokens:
    SIGSTORE_ID_TOKEN:
      aud: sigstore
    AWS_OIDC_TOKEN:
      aud: https://sts.amazonaws.com
  script:
    - deploy.sh
"#;
        let graph = parse(yaml);
        let oidc: Vec<_> = graph
            .nodes_of_kind(NodeKind::Identity)
            .filter(|n| n.metadata.get(META_OIDC).map(String::as_str) == Some("true"))
            .collect();
        assert_eq!(
            oidc.len(),
            2,
            "expected 2 OIDC identity nodes, got: {:?}",
            oidc.iter().map(|n| &n.name).collect::<Vec<_>>()
        );
    }

    #[test]
    fn explicit_secrets_emit_secret_nodes() {
        let yaml = r#"
deploy:
  secrets:
    DATABASE_PASSWORD:
      vault: production/db/password@secret
    AWS_KEY:
      aws_secrets_manager:
        name: my-secret
  script:
    - deploy.sh
"#;
        let graph = parse(yaml);
        let secrets: Vec<_> = graph.nodes_of_kind(NodeKind::Secret).collect();
        let names: Vec<_> = secrets.iter().map(|s| s.name.as_str()).collect();
        assert!(names.contains(&"DATABASE_PASSWORD"), "got: {names:?}");
        assert!(names.contains(&"AWS_KEY"), "got: {names:?}");
    }

    #[test]
    fn rules_mr_trigger_sets_meta_trigger() {
        let yaml = r#"
test:
  rules:
    - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
  script:
    - run tests
"#;
        let graph = parse(yaml);
        assert_eq!(
            graph.metadata.get(META_TRIGGER).map(String::as_str),
            Some("merge_request"),
            "META_TRIGGER must be set to merge_request"
        );
    }

    #[test]
    fn only_merge_requests_sets_meta_trigger() {
        let yaml = r#"
test:
  only:
    - merge_requests
  script:
    - run tests
"#;
        let graph = parse(yaml);
        assert_eq!(
            graph.metadata.get(META_TRIGGER).map(String::as_str),
            Some("merge_request")
        );
    }

    #[test]
    fn include_marks_graph_partial() {
        let yaml = r#"
include:
  - local: '/templates/.base.yml'

build:
  script:
    - make
"#;
        let graph = parse(yaml);
        assert_eq!(graph.completeness, AuthorityCompleteness::Partial);
        assert_eq!(graph.completeness_gap_kinds[0], GapKind::Structural);
    }

    #[test]
    fn extends_marks_graph_partial() {
        let yaml = r#"
.base:
  script:
    - echo base

my-job:
  extends: .base
  stage: build
"#;
        let graph = parse(yaml);
        assert_eq!(graph.completeness, AuthorityCompleteness::Partial);
        // Two structural gaps: the hidden `.base` template job and the
        // `extends:` inheritance on my-job.
        assert!(
            graph
                .completeness_gap_kinds
                .iter()
                .all(|k| *k == GapKind::Structural),
            "expected all gaps Structural, got: {:?}",
            graph.completeness_gap_kinds
        );
    }

    #[test]
    fn meta_job_name_set_on_step_nodes() {
        let yaml = r#"
build:
  script:
    - make
deploy:
  script:
    - deploy.sh
"#;
        let graph = parse(yaml);
        let steps: Vec<_> = graph.nodes_of_kind(NodeKind::Step).collect();
        assert_eq!(steps.len(), 2);
        for step in &steps {
            assert!(
                step.metadata.contains_key(META_JOB_NAME),
                "Step '{}' missing META_JOB_NAME",
                step.name
            );
        }
        // Verify job names are correct
        let names: Vec<_> = steps
            .iter()
            .map(|s| s.metadata.get(META_JOB_NAME).unwrap().as_str())
            .collect();
        assert!(names.contains(&"build"), "got: {names:?}");
        assert!(names.contains(&"deploy"), "got: {names:?}");
    }

    #[test]
    fn reserved_keywords_not_parsed_as_jobs() {
        let yaml = r#"
stages:
  - build
  - test

variables:
  MY_VAR: value

image: alpine:latest

build:
  stage: build
  script:
    - make
"#;
        let graph = parse(yaml);
        let steps: Vec<_> = graph.nodes_of_kind(NodeKind::Step).collect();
        assert_eq!(
            steps.len(),
            1,
            "only 'build' should be a Step, got: {:?}",
            steps.iter().map(|s| &s.name).collect::<Vec<_>>()
        );
        assert_eq!(steps[0].name, "build");
    }

    #[test]
    fn services_emit_image_nodes() {
        let yaml = r#"
test:
  services:
    - docker:dind
    - name: postgres:14
  script:
    - run_tests
"#;
        let graph = parse(yaml);
        let images: Vec<_> = graph.nodes_of_kind(NodeKind::Image).collect();
        assert_eq!(
            images.len(),
            2,
            "expected 2 service Image nodes, got: {:?}",
            images.iter().map(|i| &i.name).collect::<Vec<_>>()
        );
    }

    // ── Cross-platform misclassification trap (red-team R2 #5) ─────

    #[test]
    fn job_carrier_with_unparseable_bodies_marks_partial() {
        // Top-level keys that look like job names but whose values are not
        // mappings (lists, scalars). GitLab parser would normally produce a
        // Step per non-reserved mapping-valued key; here every candidate is
        // skipped because the value is not a mapping. Result: 0 step nodes
        // despite a non-empty job carrier — must mark Partial.
        let yaml = r#"
build:
  - this is a list, not a mapping
test:
  - also a list
"#;
        let graph = parse(yaml);
        let step_count = graph
            .nodes
            .iter()
            .filter(|n| n.kind == NodeKind::Step)
            .count();
        // Note: the "had_job_carrier" heuristic only fires when the value IS
        // a mapping, so this case (non-mapping values) does NOT trigger the
        // partial — that's intentional. The heuristic targets the trap where
        // an attacker uses a *valid mapping shape* the GitLab parser can't
        // interpret.
        assert_eq!(step_count, 0);
        assert_eq!(
            graph.completeness,
            AuthorityCompleteness::Complete,
            "non-mapping values are not job carriers"
        );
    }

    #[test]
    fn mapping_jobs_without_recognisable_step_content_marks_partial() {
        // A non-reserved top-level key whose value is a mapping but contains
        // only ADO-style fields (`task:`, `azureSubscription`) — and `extends`
        // marks the job as partial without creating a Step. Wait: the GitLab
        // parser actually still adds a Step node for any mapping-valued
        // non-reserved key. So to get the 0-step + had_carrier shape, we
        // need a hidden/template job (starts with '.') as the only candidate.
        let yaml = r#"
.template-only:
  script:
    - echo "this is a template-only file"
"#;
        let graph = parse(yaml);
        let step_count = graph
            .nodes
            .iter()
            .filter(|n| n.kind == NodeKind::Step)
            .count();
        assert_eq!(step_count, 0);
        // Hidden jobs already mark partial with their own reason.
        assert_eq!(graph.completeness, AuthorityCompleteness::Partial);
        // The hidden `.template-only` job is a Structural gap. The zero-steps
        // fall-through does NOT fire here because `had_job_carrier` only
        // counts non-dot-prefixed mapping-valued top-level keys.
        assert_eq!(graph.completeness_gap_kinds[0], GapKind::Structural);
    }
}