provenant/parsers/

conda.rs

// SPDX-FileCopyrightText: nexB Inc. and others
// SPDX-FileCopyrightText: Provenant contributors
// SPDX-License-Identifier: Apache-2.0
// Derived from ScanCode Toolkit (Apache-2.0); modified. See NOTICE.

//! Parser for Conda/Anaconda package manifest files.
//!
//! Extracts package metadata and dependencies from Conda ecosystem manifest files
//! supporting both recipe definitions and environment specifications.
//!
//! # Supported Formats
//! - meta.yaml (Conda recipe metadata with Jinja2 templating support)
//! - conda.yaml/environment.yml (Conda environment dependency specifications)
//!
//! # Key Features
//! - YAML parsing for environment files
//! - Dependency extraction from dependencies and build_requirements sections
//! - Channel specification and platform detection
//! - Version constraint parsing for Conda version specifiers
//! - Package URL (purl) generation for conda packages
//! - Limited meta.yaml support (note: Jinja2 templating not fully resolved)
//!
//! # Implementation Notes
//! - Uses YAML parsing via `yaml_serde`
//! - meta.yaml: Jinja2 templates not evaluated (use rendered YAML if available)
//! - environment.yml: Full dependency specification support
//! - Graceful error handling with `warn!()` logs
//!
//! # References
//! - <https://docs.conda.io/projects/conda-build/en/latest/resources/define-metadata.html>
//! - <https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-environments.html>

use std::collections::HashMap;
use std::path::Path;

use packageurl::PackageUrl;

use crate::parser_warn as warn;
use crate::parsers::utils::{MAX_ITERATION_COUNT, read_file_to_string, truncate_field};
use regex::Regex;
use yaml_serde::Value;

use crate::models::{DatasourceId, Dependency, PackageData, PackageType, Sha256Digest};

use super::PackageParser;
use super::license_normalization::{
    DeclaredLicenseMatchMetadata, build_declared_license_data_from_pair,
    normalize_spdx_declared_license,
};

fn default_package_data(datasource_id: Option<DatasourceId>) -> PackageData {
    PackageData {
        package_type: Some(CondaMetaYamlParser::PACKAGE_TYPE),
        datasource_id,
        ..Default::default()
    }
}

fn is_conda_recipe_yaml_path(path: &Path) -> bool {
    let Some(name) = path.file_name().and_then(|name| name.to_str()) else {
        return false;
    };
    if name != "recipe.yaml" && name != "recipe.yml" {
        return false;
    }
    path.parent()
        .and_then(|parent| parent.file_name())
        .and_then(|name| name.to_str())
        .is_some_and(|name| name == "recipe")
}

/// Build a PURL (Package URL) for Conda or PyPI packages.
///
/// The conda purl-spec prohibits a namespace: the channel is a `?channel=`
/// qualifier (not a namespace segment) and the build string is a `?build=`
/// qualifier. `channel`/`build` are ignored for non-conda types.
pub(crate) fn build_purl(
    package_type: &str,
    channel: Option<&str>,
    name: &str,
    version: Option<&str>,
    build: Option<&str>,
) -> Option<String> {
    let mut purl = PackageUrl::new(package_type, name).ok()?;

    if let Some(version) = version.filter(|v| !v.is_empty()) {
        purl.with_version(version).ok()?;
    }

    if package_type == "conda" {
        if let Some(channel) = channel.filter(|c| !c.is_empty()) {
            purl.add_qualifier("channel", channel).ok()?;
        }
        if let Some(build) = build.filter(|b| !b.is_empty()) {
            purl.add_qualifier("build", build).ok()?;
        }
    }

    Some(purl.to_string())
}

fn build_conda_package_purl(name: Option<&str>, version: Option<&str>) -> Option<String> {
    let name = name?;
    build_purl("conda", None, name, version, None)
}

fn yaml_value_to_string(value: &Value) -> Option<String> {
    match value {
        Value::String(s) => Some(truncate_field(s.clone())),
        Value::Number(n) => Some(truncate_field(n.to_string())),
        Value::Bool(b) => Some(truncate_field(b.to_string())),
        _ => None,
    }
}

fn extract_jinja_statement(trimmed_line: &str) -> Option<&str> {
    if !trimmed_line.starts_with("{%") {
        return None;
    }

    let end = trimmed_line.find("%}")?;
    Some(trimmed_line[2..end].trim())
}

fn extract_conda_requirement_name(req: &str) -> Option<String> {
    let req = req.trim();
    if req.is_empty() {
        return None;
    }

    let req_without_ns = req.rsplit_once("::").map(|(_, rest)| rest).unwrap_or(req);

    let name = req_without_ns
        .split_whitespace()
        .next()
        .unwrap_or(req_without_ns)
        .split(['=', '<', '>', '!', '~'])
        .next()
        .unwrap_or(req_without_ns)
        .trim();

    if name.is_empty() {
        None
    } else {
        Some(truncate_field(name.to_string()))
    }
}

/// Conda recipe manifest (meta.yaml) parser.
///
/// Extracts package metadata and dependencies from Conda recipe files, which
/// define how to build a Conda package. Handles Jinja2 templating used in
/// recipe files for variable substitution.
pub struct CondaMetaYamlParser;

impl PackageParser for CondaMetaYamlParser {
    const PACKAGE_TYPE: PackageType = PackageType::Conda;

    fn is_match(path: &Path) -> bool {
        // Match */meta.yaml following Python reference logic
        path.file_name()
            .is_some_and(|name| name == "meta.yaml" || name == "meta.yml")
            || is_conda_recipe_yaml_path(path)
    }

    fn extract_packages(path: &Path) -> Vec<PackageData> {
        let contents = match read_file_to_string(path, None) {
            Ok(c) => c,
            Err(e) => {
                warn!("Failed to read {}: {}", path.display(), e);
                return vec![default_package_data(Some(DatasourceId::CondaMetaYaml))];
            }
        };

        if is_conda_recipe_yaml_path(path) {
            let yaml: Value = match yaml_serde::from_str(&contents) {
                Ok(y) => y,
                Err(e) => {
                    warn!("Failed to parse YAML in {}: {}", path.display(), e);
                    return vec![default_package_data(Some(DatasourceId::CondaMetaYaml))];
                }
            };

            if !looks_like_conda_recipe_yaml(&yaml) {
                return Vec::new();
            }

            return vec![parse_conda_recipe_yaml(&yaml)];
        }

        // Extract Jinja2 variables and apply crude substitution
        let variables = extract_jinja2_variables(&contents);
        let processed_yaml = apply_jinja2_substitutions(&contents, &variables);

        // Parse YAML after Jinja2 processing
        let yaml: Value = match yaml_serde::from_str(&processed_yaml) {
            Ok(y) => y,
            Err(e) => {
                warn!("Failed to parse YAML in {}: {}", path.display(), e);
                return vec![default_package_data(Some(DatasourceId::CondaMetaYaml))];
            }
        };

        let package_element = yaml.get("package").and_then(|v| v.as_mapping());
        let name = package_element
            .and_then(|p| p.get("name"))
            .and_then(yaml_value_to_string);

        let version = package_element
            .and_then(|p| p.get("version"))
            .and_then(yaml_value_to_string);

        let source = yaml.get("source").and_then(|v| v.as_mapping());
        let download_url = source
            .and_then(|s| s.get("url"))
            .and_then(|v| v.as_str())
            .map(|s| truncate_field(s.to_string()));

        let sha256 = source
            .and_then(|s| s.get("sha256"))
            .and_then(|v| v.as_str())
            .and_then(|s| Sha256Digest::from_hex(s).ok());

        let about = yaml.get("about").and_then(|v| v.as_mapping());
        let homepage_url = about
            .and_then(|a| a.get("home"))
            .and_then(|v| v.as_str())
            .map(|s| truncate_field(s.to_string()));

        let extracted_license_statement = about
            .and_then(|a| a.get("license"))
            .and_then(|v| v.as_str())
            .map(|s| truncate_field(s.to_string()));
        let (declared_license_expression, declared_license_expression_spdx, license_detections) =
            normalize_conda_declared_license(extracted_license_statement.as_deref());

        let description = about
            .and_then(|a| a.get("summary"))
            .and_then(|v| v.as_str())
            .map(|s| truncate_field(s.to_string()));

        let vcs_url = about
            .and_then(|a| a.get("dev_url"))
            .and_then(|v| v.as_str())
            .map(|s| truncate_field(s.to_string()));
        let license_file = about
            .and_then(|a| a.get("license_file"))
            .and_then(|v| v.as_str())
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(|s| truncate_field(s.to_string()));

        // Extract dependencies from requirements sections
        let mut dependencies = Vec::new();
        let mut extra_data: HashMap<String, serde_json::Value> = HashMap::new();

        if let Some(requirements) = yaml.get("requirements").and_then(|v| v.as_mapping()) {
            for (scope_key, reqs_value) in requirements {
                let scope = scope_key.as_str().unwrap_or("unknown");
                if let Some(reqs) = reqs_value.as_sequence() {
                    for req in reqs.iter().take(MAX_ITERATION_COUNT) {
                        if let Some(req_str) = req.as_str()
                            && let Some(dep) = parse_conda_requirement(req_str, scope)
                        {
                            // Filter out pip/python from dependencies, add to extra_data
                            if extract_conda_requirement_name(req_str)
                                .is_some_and(|n| n == "pip" || n == "python")
                            {
                                if let Some(arr) = extra_data
                                    .entry(scope.to_string())
                                    .or_insert_with(|| serde_json::Value::Array(vec![]))
                                    .as_array_mut()
                                {
                                    arr.push(serde_json::Value::String(truncate_field(
                                        req_str.to_string(),
                                    )))
                                }
                            } else {
                                dependencies.push(dep);
                            }
                        }
                    }
                }
            }
        }

        let mut pkg = default_package_data(Some(DatasourceId::CondaMetaYaml));
        pkg.package_type = Some(Self::PACKAGE_TYPE);
        pkg.datasource_id = Some(DatasourceId::CondaMetaYaml);
        pkg.name = name;
        pkg.version = version;
        pkg.purl = build_conda_package_purl(pkg.name.as_deref(), pkg.version.as_deref());
        pkg.download_url = download_url;
        pkg.homepage_url = homepage_url;
        pkg.declared_license_expression = declared_license_expression.map(truncate_field);
        pkg.declared_license_expression_spdx = declared_license_expression_spdx.map(truncate_field);
        pkg.license_detections = license_detections;
        pkg.extracted_license_statement = extracted_license_statement.map(truncate_field);
        pkg.description = description;
        pkg.vcs_url = vcs_url;
        pkg.sha256 = sha256;
        pkg.dependencies = dependencies;
        if let Some(license_file) = license_file {
            extra_data.insert(
                "license_file".to_string(),
                serde_json::Value::String(license_file),
            );
        }
        if !extra_data.is_empty() {
            pkg.extra_data = Some(extra_data);
        }
        vec![pkg]
    }

    fn metadata() -> Vec<super::metadata::ParserMetadata> {
        vec![super::metadata::ParserMetadata {
            description: "Conda package manifest and environment file",
            file_patterns: &[
                "**/meta.yaml",
                "**/meta.yml",
                "**/recipe/recipe.yaml",
                "**/recipe/recipe.yml",
                "**/environment.yml",
                "**/environment.yaml",
                "**/env.yaml",
                "**/env.yml",
                "**/conda.yaml",
                "**/conda.yml",
                "**/*conda*.yaml",
                "**/*conda*.yml",
                "**/*env*.yaml",
                "**/*env*.yml",
                "**/*environment*.yaml",
                "**/*environment*.yml",
            ],
            package_type: "conda",
            primary_language: "Python",
            documentation_url: Some("https://docs.conda.io/"),
        }]
    }
}

fn looks_like_conda_recipe_yaml(yaml: &Value) -> bool {
    // rattler-build treats schema_version as optional, defaulting to 1, so many real
    // recipe.yaml files omit it. Accept an absent schema_version (default 1) and reject
    // only an explicit version this parser does not understand.
    let schema_version_ok = match yaml.get("schema_version").and_then(|value| value.as_u64()) {
        Some(version) => version == 1,
        None => true,
    };

    schema_version_ok
        && (yaml
            .get("package")
            .and_then(|value| value.as_mapping())
            .is_some()
            || yaml
                .get("recipe")
                .and_then(|value| value.as_mapping())
                .is_some())
}

fn parse_conda_recipe_yaml(yaml: &Value) -> PackageData {
    let context = extract_recipe_yaml_context(yaml);
    let package = yaml
        .get("package")
        .or_else(|| yaml.get("recipe"))
        .and_then(|value| value.as_mapping());
    let source = yaml.get("source").and_then(|value| value.as_mapping());
    let about = yaml.get("about").and_then(|value| value.as_mapping());

    let name = package
        .and_then(|pkg| pkg.get("name"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));
    let version = package
        .and_then(|pkg| pkg.get("version"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));

    let download_url = source
        .and_then(|src| src.get("url"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));
    let sha256 = source
        .and_then(|src| src.get("sha256"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context))
        .and_then(|value| Sha256Digest::from_hex(&value).ok());

    let extracted_license_statement = about
        .and_then(|section| section.get("license"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));
    let (declared_license_expression, declared_license_expression_spdx, license_detections) =
        normalize_conda_declared_license(extracted_license_statement.as_deref());

    let description = about
        .and_then(|section| section.get("summary"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));
    let homepage_url = about
        .and_then(|section| section.get("homepage").or_else(|| section.get("home")))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));
    let vcs_url = about
        .and_then(|section| {
            section
                .get("repository")
                .or_else(|| section.get("dev_url"))
                .or_else(|| section.get("repository_url"))
        })
        .and_then(|value| recipe_yaml_value_to_string(value, &context));
    let documentation_url = about
        .and_then(|section| section.get("documentation"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));
    let license_file = about
        .and_then(|section| section.get("license_file"))
        .and_then(|value| recipe_yaml_value_to_string(value, &context));

    let mut dependencies = Vec::new();
    let mut extra_data: HashMap<String, serde_json::Value> = HashMap::new();
    if let Some(requirements) = yaml
        .get("requirements")
        .and_then(|value| value.as_mapping())
    {
        for (scope_key, reqs_value) in requirements {
            let Some(scope) = scope_key.as_str() else {
                continue;
            };
            let recipe_requirements = extract_recipe_yaml_requirement_strings(reqs_value, &context);
            if recipe_requirements.is_empty() {
                continue;
            }

            for req in &recipe_requirements {
                if extract_conda_requirement_name(req)
                    .is_some_and(|name| name == "pip" || name == "python")
                {
                    if let Some(arr) = extra_data
                        .entry(scope.to_string())
                        .or_insert_with(|| serde_json::Value::Array(vec![]))
                        .as_array_mut()
                    {
                        arr.push(serde_json::Value::String(truncate_field(req.clone())));
                    }
                    continue;
                }

                if let Some(dep) = parse_conda_requirement(req, scope) {
                    dependencies.push(dep);
                }
            }
        }
    }

    if let Some(documentation_url) = documentation_url {
        extra_data.insert(
            "documentation".to_string(),
            serde_json::Value::String(documentation_url),
        );
    }
    if let Some(license_file) = license_file {
        extra_data.insert(
            "license_file".to_string(),
            serde_json::Value::String(license_file),
        );
    }
    extra_data.insert("schema_version".to_string(), serde_json::json!(1));

    let mut pkg = default_package_data(Some(DatasourceId::CondaMetaYaml));
    pkg.package_type = Some(CondaMetaYamlParser::PACKAGE_TYPE);
    pkg.datasource_id = Some(DatasourceId::CondaMetaYaml);
    pkg.name = name;
    pkg.version = version;
    pkg.purl = build_conda_package_purl(pkg.name.as_deref(), pkg.version.as_deref());
    pkg.download_url = download_url;
    pkg.homepage_url = homepage_url;
    pkg.declared_license_expression = declared_license_expression.map(truncate_field);
    pkg.declared_license_expression_spdx = declared_license_expression_spdx.map(truncate_field);
    pkg.license_detections = license_detections;
    pkg.extracted_license_statement = extracted_license_statement.map(truncate_field);
    pkg.description = description;
    pkg.vcs_url = vcs_url;
    pkg.sha256 = sha256;
    pkg.dependencies = dependencies;
    pkg.extra_data = Some(extra_data);
    pkg
}

fn extract_recipe_yaml_context(yaml: &Value) -> HashMap<String, String> {
    let mut context = HashMap::new();
    let Some(context_mapping) = yaml.get("context").and_then(|value| value.as_mapping()) else {
        return context;
    };

    for (key, value) in context_mapping {
        let Some(key) = key.as_str() else {
            continue;
        };
        if let Some(value) = yaml_value_to_string(value) {
            context.insert(truncate_field(key.to_string()), truncate_field(value));
        }
    }

    context
}

fn recipe_yaml_value_to_string(value: &Value, context: &HashMap<String, String>) -> Option<String> {
    let value = yaml_value_to_string(value)?;
    Some(resolve_recipe_yaml_expressions(&value, context))
}

fn resolve_recipe_yaml_expressions(value: &str, context: &HashMap<String, String>) -> String {
    // rattler-build recipe.yaml uses `${{ var }}` substitution from the `context:` block,
    // optionally with a minijinja filter such as `${{ name|lower }}`. Capture the variable
    // and an optional single filter so templated package names resolve to real identities
    // instead of leaking the literal expression into PURLs.
    let Some(re) = Regex::new(
        r#"\$\{\{\s*([A-Za-z_][A-Za-z0-9_]*)\s*(?:\|\s*([A-Za-z_][A-Za-z0-9_]*)\s*)?\}\}"#,
    )
    .ok() else {
        return truncate_field(value.to_string());
    };

    let resolved = re.replace_all(value, |caps: &regex::Captures| {
        let Some(substituted) = context.get(&caps[1]) else {
            // Unknown variable: leave the original expression untouched.
            return caps[0].to_string();
        };
        match caps.get(2).map(|filter| filter.as_str()) {
            Some("lower") => substituted.to_lowercase(),
            Some("upper") => substituted.to_uppercase(),
            // Unknown/no filter: use the substituted value as-is.
            _ => substituted.clone(),
        }
    });
    truncate_field(resolved.into_owned())
}

fn extract_recipe_yaml_requirement_strings(
    value: &Value,
    context: &HashMap<String, String>,
) -> Vec<String> {
    let mut requirements = Vec::new();
    collect_recipe_yaml_requirement_strings(value, context, &mut requirements);
    requirements
}

fn collect_recipe_yaml_requirement_strings(
    value: &Value,
    context: &HashMap<String, String>,
    requirements: &mut Vec<String>,
) {
    if let Some(req) = value.as_str() {
        let resolved = resolve_recipe_yaml_expressions(req, context);
        if should_keep_recipe_yaml_requirement(&resolved) {
            requirements.push(resolved);
        }
        return;
    }

    if let Some(items) = value.as_sequence() {
        for item in items.iter().take(MAX_ITERATION_COUNT) {
            collect_recipe_yaml_requirement_strings(item, context, requirements);
        }
        return;
    }

    if let Some(mapping) = value.as_mapping() {
        if let Some(then_value) = mapping.get("then") {
            collect_recipe_yaml_requirement_strings(then_value, context, requirements);
        }
        if let Some(else_value) = mapping.get("else") {
            collect_recipe_yaml_requirement_strings(else_value, context, requirements);
        }
    }
}

fn should_keep_recipe_yaml_requirement(req: &str) -> bool {
    let trimmed = req.trim();
    if trimmed.is_empty() {
        return false;
    }

    !(trimmed.contains("${{")
        || trimmed.contains("compiler('")
        || trimmed.contains("compiler(\"")
        || trimmed.contains("pin_subpackage(")
        || trimmed.contains("pin_compatible(")
        || trimmed.contains("stdlib('")
        || trimmed.contains("stdlib(\""))
}

fn normalize_conda_declared_license(
    statement: Option<&str>,
) -> (
    Option<String>,
    Option<String>,
    Vec<crate::models::LicenseDetection>,
) {
    match statement.map(str::trim).filter(|value| !value.is_empty()) {
        Some("Apache Software") => build_declared_license_data_from_pair(
            "apache-2.0",
            "Apache-2.0",
            DeclaredLicenseMatchMetadata::single_line("Apache Software"),
        ),
        Some("BSD-3-Clause") => build_declared_license_data_from_pair(
            "bsd-new",
            "BSD-3-Clause",
            DeclaredLicenseMatchMetadata::single_line("BSD-3-Clause"),
        ),
        other => normalize_spdx_declared_license(other),
    }
}

/// Conda environment file (environment.yml, conda.yaml) parser.
///
/// Extracts dependencies from Conda environment files used to define reproducible
/// environments. Supports both Conda and pip dependencies, with channel specifications.
pub struct CondaEnvironmentYmlParser;

impl PackageParser for CondaEnvironmentYmlParser {
    const PACKAGE_TYPE: PackageType = PackageType::Conda;

    fn is_match(path: &Path) -> bool {
        // Python reference: path_patterns = ('*conda*.yaml', '*env*.yaml', '*environment*.yaml')
        if let Some(name) = path.file_name().and_then(|n| n.to_str()) {
            let lower = name.to_lowercase();
            if matches!(lower.as_str(), "meta.yaml" | "meta.yml" | "recipe.yaml") {
                return false;
            }
            let has_condaish_name =
                lower.contains("conda") || lower.contains("env") || lower.contains("environment");
            let has_condaish_ancestor = path
                .ancestors()
                .skip(1)
                .filter_map(|ancestor| ancestor.file_name().and_then(|name| name.to_str()))
                .any(|ancestor| ancestor.to_ascii_lowercase().contains("conda"));
            (has_condaish_name || has_condaish_ancestor)
                && (lower.ends_with(".yaml") || lower.ends_with(".yml"))
        } else {
            false
        }
    }

    fn extract_packages(path: &Path) -> Vec<PackageData> {
        let contents = match read_file_to_string(path, None) {
            Ok(c) => c,
            Err(e) => {
                warn!("Failed to read {}: {}", path.display(), e);
                return vec![default_package_data(Some(DatasourceId::CondaYaml))];
            }
        };

        if looks_like_template_yaml(&contents) {
            return Vec::new();
        }

        let yaml: Value = match yaml_serde::from_str(&contents) {
            Ok(y) => y,
            Err(e) => {
                warn!("Failed to parse YAML in {}: {}", path.display(), e);
                return vec![default_package_data(Some(DatasourceId::CondaYaml))];
            }
        };

        if !looks_like_conda_environment_yaml(&yaml) {
            return Vec::new();
        }

        let name = yaml
            .get("name")
            .and_then(|v| v.as_str())
            .map(|s| truncate_field(s.to_string()));

        let dependencies = extract_environment_dependencies(&yaml);

        let mut extra_data = HashMap::new();
        if let Some(channels) = yaml.get("channels").and_then(|v| v.as_sequence()) {
            let channels_vec: Vec<String> = channels
                .iter()
                .filter_map(|c| c.as_str().map(|s| truncate_field(s.to_string())))
                .collect();
            if !channels_vec.is_empty() {
                extra_data.insert("channels".to_string(), serde_json::json!(channels_vec));
            }
        }

        // Environment files are private (not published packages)
        let mut pkg = default_package_data(Some(DatasourceId::CondaYaml));
        pkg.package_type = Some(Self::PACKAGE_TYPE);
        pkg.datasource_id = Some(DatasourceId::CondaYaml);
        pkg.name = name;
        pkg.purl = build_conda_package_purl(pkg.name.as_deref(), pkg.version.as_deref());
        pkg.primary_language = Some(truncate_field("Python".to_string()));
        pkg.dependencies = dependencies;
        pkg.is_private = true;
        if !extra_data.is_empty() {
            pkg.extra_data = Some(extra_data);
        }
        vec![pkg]
    }
}

fn looks_like_conda_environment_yaml(yaml: &Value) -> bool {
    let has_dependencies = yaml
        .get("dependencies")
        .and_then(|value| value.as_sequence())
        .is_some_and(|items| !items.is_empty());
    let has_channels = yaml
        .get("channels")
        .and_then(|value| value.as_sequence())
        .is_some_and(|items| !items.is_empty());
    let has_prefix = yaml
        .get("prefix")
        .and_then(|value| value.as_str())
        .is_some_and(|value| !value.trim().is_empty());

    has_dependencies || has_channels || has_prefix
}

fn looks_like_template_yaml(contents: &str) -> bool {
    contents.lines().take(MAX_ITERATION_COUNT).any(|line| {
        let trimmed = line.trim_start();
        trimmed.starts_with("{{") || trimmed.starts_with("{%-") || trimmed.starts_with("{%")
    })
}

/// Extract Jinja2-style variables from a Conda meta.yaml
///
/// For example, lines like `{% set version = "0.45.0" %}` and
/// `{% set sha256 = "abc123..." %}` are captured as variables.
pub fn extract_jinja2_variables(content: &str) -> HashMap<String, String> {
    let mut variables = HashMap::new();

    for line in content.lines().take(MAX_ITERATION_COUNT) {
        let trimmed = line.trim();
        if let Some(inner) = extract_jinja_statement(trimmed)
            && let Some(inner) = inner.strip_prefix("set").map(str::trim)
            && let Some((key, value)) = inner.split_once('=')
        {
            let key = key.trim();
            let value = value.trim().trim_matches('"').trim_matches('\'');
            variables.insert(
                truncate_field(key.to_string()),
                truncate_field(value.to_string()),
            );
        }
    }

    variables
}

/// Apply Jinja2 variable substitutions to YAML content
///
/// Supports:
/// - `{{ variable }}` - Simple substitution
/// - `{{ variable|lower }}` - Lowercase filter
pub fn apply_jinja2_substitutions(content: &str, variables: &HashMap<String, String>) -> String {
    let mut result = Vec::new();

    for line in content.lines() {
        let trimmed = line.trim();

        if extract_jinja_statement(trimmed).is_some() {
            continue;
        }

        let mut processed_line = line.to_string();

        // Apply variable substitutions
        if line.contains("{{") && line.contains("}}") {
            for (var_name, var_value) in variables {
                // Handle |lower filter
                let pattern_lower = format!("{{{{ {}|lower }}}}", var_name);
                if processed_line.contains(&pattern_lower) {
                    processed_line =
                        processed_line.replace(&pattern_lower, &var_value.to_lowercase());
                }

                // Handle normal substitution
                let pattern_normal = format!("{{{{ {} }}}}", var_name);
                processed_line = processed_line.replace(&pattern_normal, var_value);
            }
        }

        // Skip lines with unresolved Jinja2 templates (complex expressions we can't handle)
        if processed_line.contains("{{") {
            continue;
        }

        result.push(processed_line);
    }

    quote_plain_numeric_version_scalars(&result.join("\n"))
}

fn quote_plain_numeric_version_scalars(content: &str) -> String {
    let Some(version_re) =
        Regex::new(r#"^(\s*(?:-\s*)?version:\s*)([0-9]+(?:\.[0-9]+)+)(\s*)$"#).ok()
    else {
        return content.to_string();
    };

    content
        .lines()
        .map(|line| {
            version_re
                .replace(line, |caps: &regex::Captures| {
                    format!(r#"{}"{}"{}"#, &caps[1], &caps[2], &caps[3])
                })
                .into_owned()
        })
        .collect::<Vec<_>>()
        .join("\n")
}

/// Parse a Conda requirement string into a Dependency
///
/// Format examples:
/// - `mccortex ==1.0` - Pinned version with space before operator
/// - `python >=3.6` - Version constraint
/// - `conda-forge::numpy=1.15.4` - Namespace and pinned version (no space)
/// - `bwa` - No version specified
pub fn parse_conda_requirement(req: &str, scope: &str) -> Option<Dependency> {
    let req = req.trim();

    // Handle namespace prefix (conda-forge::package)
    let (namespace, channel_url, req_without_ns) = parse_conda_channel_prefix(req);

    // Split on first space to separate name from version constraint
    let (name_part, version_constraint) =
        if let Some((name, constraint)) = req_without_ns.split_once(' ') {
            (name.trim(), Some(constraint.trim()))
        } else {
            (req_without_ns, None)
        };

    // Check for pinned version with `=` (no space): package=1.0
    let (name, version, is_pinned, extracted_requirement) = if name_part.contains('=') {
        let parts: Vec<&str> = name_part.splitn(2, '=').collect();
        let n = parts[0].trim();
        let v = if parts.len() > 1 {
            let parsed = parts[1].trim();
            if parsed.is_empty() {
                None
            } else {
                Some(truncate_field(parsed.to_string()))
            }
        } else {
            None
        };
        let req = v
            .as_ref()
            .map(|ver| format!("={}", ver))
            .unwrap_or_default();
        (n, v, true, Some(truncate_field(req)))
    } else if let Some(constraint) = version_constraint {
        let version_opt = if constraint.starts_with("==") {
            Some(truncate_field(
                constraint.trim_start_matches("==").trim().to_string(),
            ))
        } else {
            None
        };
        (
            name_part.trim(),
            version_opt,
            false,
            Some(truncate_field(constraint.to_string())),
        )
    } else {
        (name_part.trim(), None, false, Some(String::new()))
    };

    // Build PURL
    let purl = build_purl("conda", namespace, name, version.as_deref(), None);

    // Determine is_runtime and is_optional based on scope
    let (is_runtime, is_optional) = match scope {
        "run" => (true, false),
        _ => (false, true), // build, host, test are all optional
    };

    let mut extra_data = HashMap::new();
    if let Some(namespace) = namespace {
        extra_data.insert(
            "channel".to_string(),
            serde_json::json!(truncate_field(namespace.to_string())),
        );
    }
    if let Some(channel_url) = channel_url {
        extra_data.insert(
            "channel_url".to_string(),
            serde_json::json!(truncate_field(channel_url.to_string())),
        );
    }

    Some(Dependency {
        purl,
        extracted_requirement,
        scope: Some(truncate_field(scope.to_string())),
        is_runtime: Some(is_runtime),
        is_optional: Some(is_optional),
        is_pinned: Some(is_pinned),
        is_direct: Some(true),
        resolved_package: None,
        extra_data: (!extra_data.is_empty()).then_some(extra_data),
    })
}

fn extract_environment_dependencies(yaml: &Value) -> Vec<Dependency> {
    let dependencies = match yaml.get("dependencies").and_then(|v| v.as_sequence()) {
        Some(d) => d,
        None => return Vec::new(),
    };

    let mut deps = Vec::new();
    for dep_value in dependencies.iter().take(MAX_ITERATION_COUNT) {
        if let Some(dep_str) = dep_value.as_str() {
            if let Some(dep) = parse_environment_string_dependency(dep_str) {
                deps.push(dep);
            }
        } else if let Some(pip_deps) = dep_value.get("pip").and_then(|v| v.as_sequence()) {
            deps.extend(extract_pip_dependencies(pip_deps));
        }
    }
    deps
}

fn parse_environment_string_dependency(dep_str: &str) -> Option<Dependency> {
    let (namespace, channel_url, dep_without_ns) = parse_conda_channel_prefix(dep_str);
    create_conda_dependency(namespace, channel_url, dep_without_ns, "dependencies")
}

fn parse_conda_exact_requirement(req_no_space: &str) -> (Option<String>, Option<String>) {
    let exact = req_no_space
        .strip_prefix("==")
        .or_else(|| req_no_space.strip_prefix('='));

    let Some(exact) = exact else {
        return (None, None);
    };

    if exact.is_empty() {
        return (None, None);
    }

    match exact.split_once('=') {
        Some((version, build_string)) if !version.is_empty() => (
            Some(truncate_field(version.to_string())),
            (!build_string.is_empty()).then(|| truncate_field(build_string.to_string())),
        ),
        _ => (Some(truncate_field(exact.to_string())), None),
    }
}

fn parse_conda_channel_prefix(dep_str: &str) -> (Option<&str>, Option<&str>, &str) {
    if let Some((ns, rest)) = dep_str.rsplit_once("::") {
        if ns.contains('/') || ns.contains(':') {
            (None, Some(ns), rest)
        } else {
            (Some(ns), None, rest)
        }
    } else {
        (None, None, dep_str)
    }
}

fn create_conda_dependency(
    namespace: Option<&str>,
    channel_url: Option<&str>,
    dep_without_ns: &str,
    scope: &str,
) -> Option<Dependency> {
    let dep = dep_without_ns.trim();
    let name_re = match Regex::new(r"^([A-Za-z0-9_.\-]+)") {
        Ok(re) => re,
        Err(_) => return None,
    };

    let caps = name_re.captures(dep)?;
    let name_match = caps.get(1)?;
    let name = name_match.as_str().trim();
    let rest = dep[name_match.end()..].trim();

    let (version, build_string, is_pinned, extracted_requirement) = if rest.is_empty() {
        (None, None, false, Some(String::new()))
    } else {
        let req_no_space = rest.replace(' ', "");
        let is_exact = req_no_space.starts_with("=") || req_no_space.starts_with("==");
        let (parsed_version, parsed_build_string) = if is_exact {
            parse_conda_exact_requirement(&req_no_space)
        } else {
            (None, None)
        };

        (
            parsed_version,
            parsed_build_string,
            is_exact,
            Some(truncate_field(rest.to_string())),
        )
    };

    if name == "pip" || name == "python" {
        return None;
    }

    let purl = build_purl(
        "conda",
        namespace,
        name,
        version.as_deref(),
        build_string.as_deref(),
    );
    let mut extra_data = HashMap::new();
    if let Some(namespace) = namespace {
        extra_data.insert(
            "channel".to_string(),
            serde_json::json!(truncate_field(namespace.to_string())),
        );
    }
    if let Some(channel_url) = channel_url {
        extra_data.insert(
            "channel_url".to_string(),
            serde_json::json!(truncate_field(channel_url.to_string())),
        );
    }
    if let Some(build_string) = build_string {
        extra_data.insert("build_string".to_string(), serde_json::json!(build_string));
    }

    Some(Dependency {
        purl,
        extracted_requirement,
        scope: Some(truncate_field(scope.to_string())),
        is_runtime: Some(true),
        is_optional: Some(false),
        is_pinned: Some(is_pinned),
        is_direct: Some(true),
        resolved_package: None,
        extra_data: (!extra_data.is_empty()).then_some(extra_data),
    })
}

fn extract_pip_dependencies(pip_deps: &[Value]) -> Vec<Dependency> {
    pip_deps
        .iter()
        .take(MAX_ITERATION_COUNT)
        .filter_map(|pip_dep| {
            if let Some(pip_req_str) = pip_dep.as_str()
                && let Some(parsed_req) =
                    crate::parsers::pep508::parse_pep508_requirement(pip_req_str)
            {
                create_pip_dependency(parsed_req, "dependencies", Some(pip_req_str))
            } else {
                None
            }
        })
        .collect()
}

fn create_pip_dependency(
    parsed_req: crate::parsers::pep508::Pep508Requirement,
    scope: &str,
    raw_requirement: Option<&str>,
) -> Option<Dependency> {
    let name = truncate_field(parsed_req.name);

    if name == "pip" || name == "python" {
        return None;
    }

    let specs = if parsed_req.is_name_at_url {
        parsed_req
            .url
            .as_ref()
            .map(|url| truncate_field(url.clone()))
    } else {
        parsed_req.specifiers.clone()
    };

    let extracted_requirement = if let Some(raw) = raw_requirement {
        let raw = raw.trim();
        let suffix = raw.strip_prefix(&name).unwrap_or(raw).trim().to_string();
        Some(truncate_field(suffix))
    } else {
        Some(truncate_field(specs.clone().unwrap_or_default()))
    };

    let version = specs.as_ref().and_then(|spec_str| {
        if spec_str.starts_with("==") {
            Some(truncate_field(
                spec_str.trim_start_matches("==").to_string(),
            ))
        } else {
            None
        }
    });

    let is_pinned = specs.as_ref().map(|s| s.contains("==")).unwrap_or(false);
    let purl = build_purl("pypi", None, &name, version.as_deref(), None);

    Some(Dependency {
        purl,
        extracted_requirement,
        scope: Some(truncate_field(scope.to_string())),
        is_runtime: Some(true),
        is_optional: Some(false),
        is_pinned: Some(is_pinned),
        is_direct: Some(true),
        resolved_package: None,
        extra_data: None,
    })
}