//! WASM bindings for did:plc operations
//!
//! This module is only compiled when both:
//! - Building for wasm32 target (`target_arch = "wasm32"`)
//! - The "wasm" feature is enabled (provides wasm_bindgen and related dependencies)

#![cfg(all(target_arch = "wasm32", feature = "wasm"))]

use crate::builder::DidBuilder as NativeDidBuilder;
use crate::crypto::{SigningKey as NativeSigningKey, VerifyingKey as NativeVerifyingKey};
use crate::did::Did as NativeDid;
use crate::document::{DidDocument as NativeDidDocument, ServiceEndpoint as NativeServiceEndpoint};
use crate::operations::Operation as NativeOperation;
use serde::{Deserialize, Serialize};
use wasm_bindgen::prelude::*;

/// WASM wrapper for DID
#[wasm_bindgen]
pub struct WasmDid {
    inner: NativeDid,
}

#[wasm_bindgen]
impl WasmDid {
    /// Parse and validate a DID string
    ///
    /// # Errors
    ///
    /// Throws a JavaScript error if the DID is invalid
    #[wasm_bindgen(constructor)]
    pub fn parse(did_string: &str) -> Result<WasmDid, JsValue> {
        NativeDid::parse(did_string)
            .map(|did| WasmDid { inner: did })
            .map_err(|e| JsValue::from_str(&e.to_string()))
    }

    /// Check if this DID is valid
    ///
    /// Since DIDs can only be constructed through validation, this always returns true
    #[wasm_bindgen(js_name = "isValid")]
    pub fn is_valid(&self) -> bool {
        self.inner.is_valid()
    }

    /// Get the 24-character identifier portion (without "did:plc:" prefix)
    #[wasm_bindgen(getter)]
    pub fn identifier(&self) -> String {
        self.inner.identifier().to_string()
    }

    /// Get the full DID string including "did:plc:" prefix
    #[wasm_bindgen(js_name = "toString")]
    pub fn to_string_js(&self) -> String {
        self.inner.to_string()
    }

    /// Get the full DID string as a getter
    #[wasm_bindgen(getter)]
    pub fn did(&self) -> String {
        self.inner.to_string()
    }
}

/// WASM wrapper for SigningKey
#[wasm_bindgen]
pub struct WasmSigningKey {
    inner: NativeSigningKey,
}

#[wasm_bindgen]
impl WasmSigningKey {
    /// Generate a new P-256 key pair
    #[wasm_bindgen(js_name = "generateP256")]
    pub fn generate_p256() -> WasmSigningKey {
        WasmSigningKey {
            inner: NativeSigningKey::generate_p256(),
        }
    }

    /// Generate a new secp256k1 key pair
    #[wasm_bindgen(js_name = "generateK256")]
    pub fn generate_k256() -> WasmSigningKey {
        WasmSigningKey {
            inner: NativeSigningKey::generate_k256(),
        }
    }

    /// Convert this signing key to a did:key string
    #[wasm_bindgen(js_name = "toDidKey")]
    pub fn to_did_key(&self) -> String {
        self.inner.to_did_key()
    }
}

/// WASM wrapper for ServiceEndpoint
#[wasm_bindgen]
#[derive(Serialize, Deserialize)]
pub struct WasmServiceEndpoint {
    /// Service type (e.g., "AtprotoPersonalDataServer")
    #[wasm_bindgen(skip)]
    pub service_type: String,
    /// Service endpoint URL
    #[wasm_bindgen(skip)]
    pub endpoint: String,
}

#[wasm_bindgen]
impl WasmServiceEndpoint {
    /// Create a new service endpoint
    #[wasm_bindgen(constructor)]
    pub fn new(service_type: String, endpoint: String) -> WasmServiceEndpoint {
        WasmServiceEndpoint {
            service_type,
            endpoint,
        }
    }

    /// Get the service type
    #[wasm_bindgen(getter = serviceType)]
    pub fn service_type(&self) -> String {
        self.service_type.clone()
    }

    /// Get the endpoint URL
    #[wasm_bindgen(getter)]
    pub fn endpoint(&self) -> String {
        self.endpoint.clone()
    }
}

impl From<WasmServiceEndpoint> for NativeServiceEndpoint {
    fn from(wasm: WasmServiceEndpoint) -> Self {
        NativeServiceEndpoint::new(wasm.service_type, wasm.endpoint)
    }
}

/// WASM wrapper for DidBuilder
#[wasm_bindgen]
pub struct WasmDidBuilder {
    inner: NativeDidBuilder,
}

#[wasm_bindgen]
impl WasmDidBuilder {
    /// Create a new DID builder
    #[wasm_bindgen(constructor)]
    pub fn new() -> WasmDidBuilder {
        WasmDidBuilder {
            inner: NativeDidBuilder::new(),
        }
    }

    /// Add a rotation key
    #[wasm_bindgen(js_name = "addRotationKey")]
    pub fn add_rotation_key(mut self, key: WasmSigningKey) -> WasmDidBuilder {
        self.inner = self.inner.add_rotation_key(key.inner);
        self
    }

    /// Add a verification method
    #[wasm_bindgen(js_name = "addVerificationMethod")]
    pub fn add_verification_method(mut self, name: String, key: WasmSigningKey) -> WasmDidBuilder {
        self.inner = self.inner.add_verification_method(name, key.inner);
        self
    }

    /// Add an also-known-as URI
    #[wasm_bindgen(js_name = "addAlsoKnownAs")]
    pub fn add_also_known_as(mut self, uri: String) -> WasmDidBuilder {
        self.inner = self.inner.add_also_known_as(uri);
        self
    }

    /// Add a service endpoint
    #[wasm_bindgen(js_name = "addService")]
    pub fn add_service(mut self, name: String, endpoint: WasmServiceEndpoint) -> WasmDidBuilder {
        self.inner = self.inner.add_service(name, endpoint.into());
        self
    }

    /// Build and sign the genesis operation
    ///
    /// Returns a JavaScript object with:
    /// - did: The created DID string
    /// - operation: The signed genesis operation as JSON
    ///
    /// # Errors
    ///
    /// Throws a JavaScript error if building fails
    #[wasm_bindgen]
    pub fn build(self) -> Result<JsValue, JsValue> {
        let (did, operation, _keys) = self
            .inner
            .build()
            .map_err(|e| JsValue::from_str(&e.to_string()))?;

        // Create a result object
        let result = js_sys::Object::new();

        // Set the DID
        js_sys::Reflect::set(
            &result,
            &JsValue::from_str("did"),
            &JsValue::from_str(did.as_str()),
        )
        .map_err(|e| JsValue::from_str(&format!("Failed to set did: {:?}", e)))?;

        // Serialize the operation to JSON
        let operation_json = serde_json::to_string(&operation)
            .map_err(|e| JsValue::from_str(&e.to_string()))?;

        js_sys::Reflect::set(
            &result,
            &JsValue::from_str("operation"),
            &JsValue::from_str(&operation_json),
        )
        .map_err(|e| JsValue::from_str(&format!("Failed to set operation: {:?}", e)))?;

        Ok(result.into())
    }
}

/// WASM wrapper for DID Document
#[wasm_bindgen]
pub struct WasmDidDocument {
    inner: NativeDidDocument,
}

#[wasm_bindgen]
impl WasmDidDocument {
    /// Parse a DID document from JSON
    #[wasm_bindgen(js_name = "fromJson")]
    pub fn from_json(json: &str) -> Result<WasmDidDocument, JsValue> {
        let doc: NativeDidDocument =
            serde_json::from_str(json).map_err(|e| JsValue::from_str(&e.to_string()))?;

        Ok(WasmDidDocument { inner: doc })
    }

    /// Convert this DID document to JSON
    #[wasm_bindgen(js_name = "toJson")]
    pub fn to_json(&self) -> Result<String, JsValue> {
        serde_json::to_string_pretty(&self.inner).map_err(|e| JsValue::from_str(&e.to_string()))
    }

    /// Get the DID this document describes
    #[wasm_bindgen(getter)]
    pub fn id(&self) -> String {
        self.inner.id.to_string()
    }

    /// Validate this DID document
    #[wasm_bindgen]
    pub fn validate(&self) -> Result<(), JsValue> {
        self.inner
            .validate()
            .map_err(|e| JsValue::from_str(&e.to_string()))
    }
}

/// WASM wrapper for VerifyingKey
#[wasm_bindgen]
pub struct WasmVerifyingKey {
    inner: NativeVerifyingKey,
}

#[wasm_bindgen]
impl WasmVerifyingKey {
    /// Create a verifying key from a did:key string
    #[wasm_bindgen(js_name = "fromDidKey")]
    pub fn from_did_key(did_key: &str) -> Result<WasmVerifyingKey, JsValue> {
        NativeVerifyingKey::from_did_key(did_key)
            .map(|key| WasmVerifyingKey { inner: key })
            .map_err(|e| JsValue::from_str(&e.to_string()))
    }

    /// Convert this verifying key to a did:key string
    #[wasm_bindgen(js_name = "toDidKey")]
    pub fn to_did_key(&self) -> String {
        self.inner.to_did_key()
    }
}

/// WASM wrapper for Operation
#[wasm_bindgen]
pub struct WasmOperation {
    inner: NativeOperation,
}

#[wasm_bindgen]
impl WasmOperation {
    /// Parse an operation from JSON
    #[wasm_bindgen(js_name = "fromJson")]
    pub fn from_json(json: &str) -> Result<WasmOperation, JsValue> {
        let op: NativeOperation =
            serde_json::from_str(json).map_err(|e| JsValue::from_str(&e.to_string()))?;

        Ok(WasmOperation { inner: op })
    }

    /// Convert this operation to JSON
    #[wasm_bindgen(js_name = "toJson")]
    pub fn to_json(&self) -> Result<String, JsValue> {
        serde_json::to_string_pretty(&self.inner).map_err(|e| JsValue::from_str(&e.to_string()))
    }

    /// Check if this is a genesis operation
    #[wasm_bindgen(js_name = "isGenesis")]
    pub fn is_genesis(&self) -> bool {
        self.inner.is_genesis()
    }

    /// Get the CID of this operation
    #[wasm_bindgen]
    pub fn cid(&self) -> Result<String, JsValue> {
        self.inner
            .cid()
            .map_err(|e| JsValue::from_str(&e.to_string()))
    }

    /// Get the prev field (CID of previous operation), or null for genesis
    #[wasm_bindgen]
    pub fn prev(&self) -> Option<String> {
        self.inner.prev().map(|s| s.to_string())
    }

    /// Get the signature of this operation
    #[wasm_bindgen]
    pub fn signature(&self) -> String {
        self.inner.signature().to_string()
    }

    /// Get the rotation keys from this operation (if any)
    #[wasm_bindgen(js_name = "rotationKeys")]
    pub fn rotation_keys(&self) -> Option<Vec<String>> {
        self.inner.rotation_keys().map(|keys| keys.to_vec())
    }

    /// Verify this operation's signature using the provided rotation keys
    ///
    /// Returns true if the signature is valid with at least one of the keys
    #[wasm_bindgen]
    pub fn verify(&self, rotation_keys: Vec<WasmVerifyingKey>) -> Result<bool, JsValue> {
        let native_keys: Vec<NativeVerifyingKey> =
            rotation_keys.into_iter().map(|k| k.inner).collect();

        match self.inner.verify(&native_keys) {
            Ok(_) => Ok(true),
            Err(_) => Ok(false),
        }
    }

    /// Verify this operation and return which key index verified it (0-based)
    ///
    /// Returns the index of the rotation key that verified the signature,
    /// or throws an error if none verified
    #[wasm_bindgen(js_name = "verifyWithKeyIndex")]
    pub fn verify_with_key_index(&self, rotation_keys: Vec<WasmVerifyingKey>) -> Result<usize, JsValue> {
        for (i, key) in rotation_keys.iter().enumerate() {
            if self.inner.verify(&[key.inner]).is_ok() {
                return Ok(i);
            }
        }
        Err(JsValue::from_str("No rotation key verified the signature"))
    }
}

/// Initialize the WASM module
///
/// This should be called before using any other functions
#[wasm_bindgen(start)]
pub fn init() {
    // WASM module initialization
    // For better panic messages in development, consider adding console_error_panic_hook
}