awsim-lambda 0.4.0

use awsim_core::{AwsError, RequestContext};
use serde_json::{Value, json};

use crate::{
    error::{invalid_parameter, resource_not_found},
    state::{LambdaState, LayerVersion},
    util::{decode_zip, now_iso8601, opt_str, require_str, sha256_base64},
};

fn layer_version_to_value(lv: &LayerVersion) -> Value {
    json!({
        "LayerArn": lv.layer_arn,
        "LayerVersionArn": lv.version_arn,
        "Version": lv.version,
        "Description": lv.description,
        "CompatibleRuntimes": lv.compatible_runtimes,
        "CodeSha256": lv.code_sha256,
        "CodeSize": lv.code_size,
        "CreatedDate": lv.created_date,
    })
}

pub fn publish_layer_version(
    state: &LambdaState,
    input: &Value,
    ctx: &RequestContext,
) -> Result<Value, AwsError> {
    let layer_name = require_str(input, "LayerName")?;
    let description = opt_str(input, "Description").unwrap_or("").to_string();

    let compatible_runtimes: Vec<String> = input
        .get("CompatibleRuntimes")
        .and_then(|v| v.as_array())
        .map(|arr| {
            arr.iter()
                .filter_map(|v| v.as_str().map(str::to_string))
                .collect()
        })
        .unwrap_or_default();

    // Resolve code
    let (code_data, code_sha256, code_size) = if let Some(content) = input.get("Content") {
        if let Some(zip_b64) = content.get("ZipFile").and_then(|v| v.as_str()) {
            let (bytes, hash, size) = decode_zip(zip_b64)?;
            (Some(bytes), hash, size)
        } else {
            let placeholder = b"s3-placeholder";
            (None, sha256_base64(placeholder), 0u64)
        }
    } else {
        return Err(invalid_parameter(
            "Content is required for PublishLayerVersion",
        ));
    };

    let layer_arn = format!(
        "arn:aws:lambda:{}:{}:layer:{}",
        ctx.region, ctx.account_id, layer_name
    );

    let mut versions = state.layers.entry(layer_name.to_string()).or_default();

    let version_number = (versions.len() + 1) as u64;
    let version_arn = format!("{}:{}", layer_arn, version_number);

    let lv = LayerVersion {
        layer_name: layer_name.to_string(),
        layer_arn: layer_arn.clone(),
        version_arn: version_arn.clone(),
        version: version_number,
        description,
        compatible_runtimes,
        code_sha256,
        code_size,
        code_data,
        created_date: now_iso8601(),
        tags: std::collections::HashMap::new(),
    };

    let result = layer_version_to_value(&lv);
    versions.push(lv);

    Ok(result)
}

pub fn list_layers(
    state: &LambdaState,
    input: &Value,
    _ctx: &RequestContext,
) -> Result<Value, AwsError> {
    use awsim_core::pagination::{cap_max_results, paginate};

    let mut all: Vec<(String, LayerVersion)> = state
        .layers
        .iter()
        .filter_map(|entry| {
            entry
                .value()
                .last()
                .cloned()
                .map(|latest| (entry.key().clone(), latest))
        })
        .collect();
    all.sort_by(|a, b| a.0.cmp(&b.0));

    let max = cap_max_results(input.get("MaxItems").and_then(Value::as_i64), 50, 50);
    let marker = input.get("Marker").and_then(Value::as_str);
    let page = paginate(all, max, marker, |(name, _)| name.clone())?;

    let layers: Vec<Value> = page
        .items
        .iter()
        .map(|(name, latest)| {
            json!({
                "LayerName": name,
                "LayerArn": latest.layer_arn,
                "LatestMatchingVersion": layer_version_to_value(latest),
            })
        })
        .collect();
    let mut result = json!({ "Layers": layers });
    if let Some(token) = page.next_token {
        result["NextMarker"] = json!(token);
    }
    Ok(result)
}

pub fn list_layer_versions(
    state: &LambdaState,
    input: &Value,
    _ctx: &RequestContext,
) -> Result<Value, AwsError> {
    use awsim_core::pagination::{cap_max_results, paginate};

    let layer_name = require_str(input, "LayerName")?;

    let all: Vec<LayerVersion> = match state.layers.get(layer_name) {
        Some(v) => v.iter().cloned().collect(),
        None => Vec::new(),
    };

    let max = cap_max_results(input.get("MaxItems").and_then(Value::as_i64), 50, 50);
    let marker = input.get("Marker").and_then(Value::as_str);
    // Sort by version ascending so the marker (formatted version) gives
    // a stable ordering across calls.
    let mut sorted = all;
    sorted.sort_by_key(|v| v.version);
    let page = paginate(sorted, max, marker, |v| format!("{:020}", v.version))?;

    let versions: Vec<Value> = page.items.iter().map(layer_version_to_value).collect();
    let mut result = json!({ "LayerVersions": versions });
    if let Some(token) = page.next_token {
        result["NextMarker"] = json!(token);
    }
    Ok(result)
}

pub fn get_layer_version(
    state: &LambdaState,
    input: &Value,
    _ctx: &RequestContext,
) -> Result<Value, AwsError> {
    let layer_name = require_str(input, "LayerName")?;
    let version_number = input
        .get("VersionNumber")
        .and_then(|v| {
            v.as_u64()
                .or_else(|| v.as_str().and_then(|s| s.parse::<u64>().ok()))
        })
        .ok_or_else(|| invalid_parameter("VersionNumber is required"))?;

    let entry = state
        .layers
        .get(layer_name)
        .ok_or_else(|| resource_not_found("layer", layer_name))?;

    let lv = entry
        .iter()
        .find(|v| v.version == version_number)
        .ok_or_else(|| resource_not_found("layer version", &version_number.to_string()))?;

    let mut result = layer_version_to_value(lv);
    // The Content sub-object carries a download Location alongside the
    // hash fields. AWS Location is a presigned S3 URL valid for ~10 min;
    // here we surface a stable awsim-internal URL pattern instead.
    result["Content"] = json!({
        "Location": format!("/layers/{}/{}/code.zip", lv.layer_name, lv.version),
        "CodeSha256": lv.code_sha256,
        "CodeSize": lv.code_size,
    });
    Ok(result)
}

pub fn delete_layer_version(
    state: &LambdaState,
    input: &Value,
    _ctx: &RequestContext,
) -> Result<Value, AwsError> {
    let layer_name = require_str(input, "LayerName")?;
    let version_number = input
        .get("VersionNumber")
        .and_then(|v| {
            v.as_u64()
                .or_else(|| v.as_str().and_then(|s| s.parse::<u64>().ok()))
        })
        .ok_or_else(|| invalid_parameter("VersionNumber is required"))?;

    let mut entry = state
        .layers
        .get_mut(layer_name)
        .ok_or_else(|| resource_not_found("layer", layer_name))?;

    let before = entry.len();
    entry.retain(|v| v.version != version_number);

    if entry.len() == before {
        return Err(resource_not_found(
            "layer version",
            &version_number.to_string(),
        ));
    }

    Ok(json!({}))
}

#[cfg(test)]
mod tests {
    use super::*;
    use base64::Engine as _;
    use base64::engine::general_purpose::STANDARD as BASE64;

    fn ctx() -> RequestContext {
        RequestContext::new("lambda", "us-east-1")
    }

    fn empty_zip_b64() -> String {
        // Minimal valid ZIP file (empty central directory).
        let bytes: [u8; 22] = [
            0x50, 0x4b, 0x05, 0x06, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        ];
        BASE64.encode(bytes)
    }

    #[test]
    fn get_layer_version_returns_metadata_and_content() {
        let state = LambdaState::default();
        publish_layer_version(
            &state,
            &json!({
                "LayerName": "shared",
                "Description": "test",
                "CompatibleRuntimes": ["nodejs20.x"],
                "Content": { "ZipFile": empty_zip_b64() },
            }),
            &ctx(),
        )
        .unwrap();

        let got = get_layer_version(
            &state,
            &json!({ "LayerName": "shared", "VersionNumber": 1u64 }),
            &ctx(),
        )
        .unwrap();

        assert_eq!(got["Version"], json!(1));
        assert_eq!(
            got["LayerArn"].as_str().unwrap(),
            "arn:aws:lambda:us-east-1:000000000000:layer:shared"
        );
        let content = got.get("Content").expect("Content present");
        assert!(content.get("Location").is_some());
        assert_eq!(content["CodeSha256"], got["CodeSha256"]);
        assert_eq!(content["CodeSize"], got["CodeSize"]);
    }

    #[test]
    fn get_layer_version_unknown_version_returns_resource_not_found() {
        let state = LambdaState::default();
        publish_layer_version(
            &state,
            &json!({
                "LayerName": "shared",
                "Content": { "ZipFile": empty_zip_b64() },
            }),
            &ctx(),
        )
        .unwrap();

        let err = get_layer_version(
            &state,
            &json!({ "LayerName": "shared", "VersionNumber": 99u64 }),
            &ctx(),
        )
        .unwrap_err();
        assert_eq!(err.code, "ResourceNotFoundException");
    }
}