use sha2::{Digest, Sha256, Sha512};
use md5::Md5;
use crate::meta_plugin::MetaPlugin;

#[derive(Debug, Clone)]
enum HashMethod {
    Md5,
    Sha256,
    Sha512,
}

impl Default for HashMethod {
    fn default() -> Self {
        HashMethod::Sha256
    }
}

impl HashMethod {
    fn from_str(s: &str) -> Option<Self> {
        match s {
            "md5" => Some(HashMethod::Md5),
            "sha256" => Some(HashMethod::Sha256),
            "sha512" => Some(HashMethod::Sha512),
            _ => None,
        }
    }
}

#[derive(Debug, Clone)]
pub struct DigestMetaPlugin {
    md5_hasher: Option<Md5>,
    sha256_hasher: Option<Sha256>,
    sha512_hasher: Option<Sha512>,
    is_finalized: bool,
    meta_name: String,
    outputs: std::collections::HashMap<String, serde_yaml::Value>,
    options: std::collections::HashMap<String, serde_yaml::Value>,
    methods: Vec<HashMethod>,
}

impl Default for DigestMetaPlugin {
    fn default() -> Self {
        Self {
            md5_hasher: None,
            sha256_hasher: None,
            sha512_hasher: None,
            is_finalized: false,
            meta_name: "digest".to_string(),
            outputs: std::collections::HashMap::new(),
            options: std::collections::HashMap::new(),
            methods: vec![HashMethod::Sha256],
        }
    }
}

impl DigestMetaPlugin {
    pub fn new(
        options: Option<std::collections::HashMap<String, serde_yaml::Value>>,
        outputs: Option<std::collections::HashMap<String, serde_yaml::Value>>,
    ) -> DigestMetaPlugin {
        let mut plugin = DigestMetaPlugin::default();
        
        // Set default outputs
        let default_outputs = vec![
            ("digest_md5".to_string(), serde_yaml::Value::String("digest_md5".to_string())),
            ("digest_sha256".to_string(), serde_yaml::Value::String("digest_sha256".to_string())),
            ("digest_sha512".to_string(), serde_yaml::Value::String("digest_sha512".to_string())),
        ];
        for (key, value) in default_outputs {
            plugin.outputs.insert(key, value);
        }
        
        // Apply provided options
        if let Some(opts) = options {
            for (key, value) in opts {
                plugin.options.insert(key, value);
            }
        }
        
        // Apply provided outputs
        if let Some(outs) = outputs {
            for (key, value) in outs {
                plugin.outputs.insert(key, value);
            }
        }
        
        // Configure methods based on options
        if let Some(method_value) = plugin.options.get("method") {
            if let Some(method_str) = method_value.as_str() {
                if let Some(method) = HashMethod::from_str(method_str) {
                    plugin.methods = vec![method];
                }
            }
        }
        
        // Initialize hashers based on selected methods
        for method in &plugin.methods {
            match method {
                HashMethod::Md5 => plugin.md5_hasher = Some(Md5::new()),
                HashMethod::Sha256 => plugin.sha256_hasher = Some(Sha256::new()),
                HashMethod::Sha512 => plugin.sha512_hasher = Some(Sha512::new()),
            }
        }
        
        plugin
    }
    
    pub fn new_simple() -> DigestMetaPlugin {
        Self::new(None, None)
    }
}

impl MetaPlugin for DigestMetaPlugin {
    fn is_finalized(&self) -> bool {
        self.is_finalized
    }
    
    fn set_finalized(&mut self, finalized: bool) {
        self.is_finalized = finalized;
    }
    
    fn initialize(&mut self) -> crate::meta_plugin::MetaPluginResponse {
        crate::meta_plugin::MetaPluginResponse {
            metadata: Vec::new(),
            is_finalized: false,
        }
    }

    fn finalize(&mut self) -> crate::meta_plugin::MetaPluginResponse {
        if self.is_finalized {
            return crate::meta_plugin::MetaPluginResponse {
                metadata: Vec::new(),
                is_finalized: true,
            };
        }
        
        let mut metadata = Vec::new();

        // Process each method
        for method in &self.methods {
            match method {
                HashMethod::Md5 => {
                    if let Some(hasher) = self.md5_hasher.take() {
                        let hash_result = hasher.finalize();
                        let hex_string = format!("{:x}", hash_result);
                        if let Some(meta_data) = crate::meta_plugin::process_metadata_outputs(
                            "digest_md5", 
                            hex_string, 
                            &self.outputs
                        ) {
                            metadata.push(meta_data);
                        }
                    }
                }
                HashMethod::Sha256 => {
                    if let Some(hasher) = self.sha256_hasher.take() {
                        let hash_result = hasher.finalize_reset();
                        let hex_string = format!("{:x}", hash_result);
                        if let Some(meta_data) = crate::meta_plugin::process_metadata_outputs(
                            "digest_sha256", 
                            hex_string, 
                            &self.outputs
                        ) {
                            metadata.push(meta_data);
                        }
                    }
                }
                HashMethod::Sha512 => {
                    if let Some(hasher) = self.sha512_hasher.take() {
                        let hash_result = hasher.finalize_reset();
                        let hex_string = format!("{:x}", hash_result);
                        if let Some(meta_data) = crate::meta_plugin::process_metadata_outputs(
                            "digest_sha512", 
                            hex_string, 
                            &self.outputs
                        ) {
                            metadata.push(meta_data);
                        }
                    }
                }
            }
        }
        
        self.is_finalized = true;
        crate::meta_plugin::MetaPluginResponse {
            metadata,
            is_finalized: true,
        }
    }

    fn update(&mut self, data: &[u8]) -> crate::meta_plugin::MetaPluginResponse {
        if self.is_finalized {
            return crate::meta_plugin::MetaPluginResponse {
                metadata: Vec::new(),
                is_finalized: true,
            };
        }
        
        for method in &self.methods {
            match method {
                HashMethod::Md5 => {
                    if let Some(hasher) = &mut self.md5_hasher {
                        hasher.update(data);
                    }
                }
                HashMethod::Sha256 => {
                    if let Some(hasher) = &mut self.sha256_hasher {
                        hasher.update(data);
                    }
                }
                HashMethod::Sha512 => {
                    if let Some(hasher) = &mut self.sha512_hasher {
                        hasher.update(data);
                    }
                }
            }
        }
        
        crate::meta_plugin::MetaPluginResponse {
            metadata: Vec::new(),
            is_finalized: false,
        }
    }

    fn meta_name(&self) -> String {
        self.meta_name.clone()
    }
    
    fn outputs(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
        &self.outputs
    }
    
    fn outputs_mut(&mut self) -> &mut std::collections::HashMap<String, serde_yaml::Value> {
        &mut self.outputs
    }
    
    fn default_outputs(&self) -> Vec<String> {
        vec![
            "digest_md5".to_string(),
            "digest_sha256".to_string(),
            "digest_sha512".to_string(),
        ]
    }
    
    fn default_options(&self) -> std::collections::HashMap<String, serde_yaml::Value> {
        let mut options = std::collections::HashMap::new();
        options.insert("method".to_string(), serde_yaml::Value::String("sha256".to_string()));
        options
    }
    
    fn options(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
        &self.options
    }
    
    fn options_mut(&mut self) -> &mut std::collections::HashMap<String, serde_yaml::Value> {
        &mut self.options
    }
}