use std::sync::{Arc, Mutex};

use anyhow::Result;
use aws_config::BehaviorVersion;
use aws_credential_types::provider::ProvideCredentials;
use aws_sdk_bedrockruntime::config::Region;
use aws_sdk_bedrockruntime::Client as BedrockRuntimeClient;

use super::convert::{build_converse_request, CachingConfig, ConversationMessage, ToolDefinition};
use super::diagnostic::BedrockDiagnosticLogger;
use super::external_config::ExternalBedrockConfig;
use super::models::apply_cross_region_prefix;
use super::response_translator::bedrock_stream_to_response_events;
use crate::ai::agent::api::LegacyResponseStream;
use crate::settings::ai::BedrockAuthMethod;

fn strip_context_marker(model_id: &str) -> String {
    if let Some(base) = model_id.strip_suffix("[1m]") {
        base.to_string()
    } else if let Some(base) = model_id.strip_suffix("[1M]") {
        base.to_string()
    } else {
        model_id.to_string()
    }
}

pub struct BedrockClient {
    runtime_client: BedrockRuntimeClient,
    region: String,
}

#[derive(Debug, Clone)]
pub struct BedrockClientConfig {
    pub auth_method: BedrockAuthMethod,
    pub profile: String,
    pub region: String,
    pub access_key_id: String,
    pub secret_access_key: String,
    pub session_token: Option<String>,
    pub cross_region_inference: bool,
    pub use_rig: bool,
}

impl BedrockClientConfig {
    /// Applies external config (from Claude Code / OpenCode) as fallback values
    /// when Galaxy's own settings are at their defaults.
    pub fn with_external_fallbacks(mut self) -> Self {
        let external = ExternalBedrockConfig::load();
        if external.is_empty() {
            return self;
        }

        if self.profile == "default" {
            if let Some(profile) = external.profile {
                log::info!("[bedrock] Using profile from external config: {profile}");
                self.profile = profile;
            }
        }

        if self.region.is_empty() {
            if let Some(region) = external.region {
                log::info!("[bedrock] Using region from external config: {region}");
                self.region = region;
            }
        }

        self
    }
}

#[derive(Debug, thiserror::Error)]
pub enum BedrockError {
    #[error("Bedrock credentials not configured")]
    CredentialsNotConfigured,
    #[error("Bedrock region not configured and could not be auto-detected")]
    RegionNotConfigured,
    #[error("Bedrock API error: {0}")]
    ApiError(String),
    #[error("Model not found: {0}")]
    ModelNotFound(String),
    #[error("Access denied: {0}")]
    AccessDenied(String),
    #[error("Throttling: {0}")]
    Throttling(String),
    #[error("Validation error: {0}")]
    ValidationError(String),
}

impl BedrockClient {
    pub async fn from_config(config: BedrockClientConfig) -> Result<Self, BedrockError> {
        log::info!(
            "[bedrock] from_config input: auth_method={:?}, profile={:?}, region={:?}, access_key_id_set={}, secret_access_key_set={}, session_token_set={}",
            config.auth_method,
            config.profile,
            config.region,
            !config.access_key_id.is_empty(),
            !config.secret_access_key.is_empty(),
            config.session_token.is_some(),
        );

        let aws_config = match config.auth_method {
            BedrockAuthMethod::Profile | BedrockAuthMethod::Sso => {
                let mut loader = aws_config::defaults(BehaviorVersion::latest());

                if !config.profile.is_empty() && config.profile != "default" {
                    loader = loader.profile_name(&config.profile);
                }

                if !config.region.is_empty() {
                    loader = loader.region(Region::new(config.region.clone()));
                }

                loader.load().await
            }
            BedrockAuthMethod::StaticKeys => {
                if config.access_key_id.is_empty() || config.secret_access_key.is_empty() {
                    return Err(BedrockError::CredentialsNotConfigured);
                }

                let creds = aws_credential_types::Credentials::new(
                    &config.access_key_id,
                    &config.secret_access_key,
                    config.session_token,
                    None,
                    "warp-bedrock-static",
                );

                let mut loader =
                    aws_config::defaults(BehaviorVersion::latest()).credentials_provider(creds);

                if !config.region.is_empty() {
                    loader = loader.region(Region::new(config.region.clone()));
                } else {
                    loader = loader.region(Region::new("us-east-1".to_string()));
                }

                loader.load().await
            }
        };

        if let Some(provider) = aws_config.credentials_provider() {
            match provider.provide_credentials().await {
                Ok(creds) => {
                    log::info!(
                        "[bedrock] Resolved AWS credentials successfully: has_access_key_id={}, has_session_token={}, expiry={:?}",
                        !creds.access_key_id().is_empty(),
                        creds.session_token().is_some(),
                        creds.expiry(),
                    );
                }
                Err(e) => {
                    log::warn!("[bedrock] Failed to resolve AWS credentials from provider: {e:?}");
                }
            }
        } else {
            log::warn!("[bedrock] No credentials provider found in resolved AWS config");
        }

        let region = aws_config
            .region()
            .map(|r| r.to_string())
            .ok_or(BedrockError::RegionNotConfigured)?;

        let runtime_client = BedrockRuntimeClient::new(&aws_config);

        Ok(Self {
            runtime_client,
            region,
        })
    }

    pub(crate) fn runtime_client(&self) -> BedrockRuntimeClient {
        self.runtime_client.clone()
    }

    pub(crate) fn region(&self) -> &str {
        &self.region
    }

    #[allow(clippy::too_many_arguments)]
    pub async fn converse_stream(
        &self,
        model_id: &str,
        task_id: &str,
        needs_create_task: bool,
        messages: Vec<ConversationMessage>,
        system_prompt: Option<String>,
        compact_summary: Option<String>,
        tools: Vec<ToolDefinition>,
        max_tokens: i32,
        temperature: Option<f32>,
        cross_region_inference: bool,
        user_query: Option<String>,
        diagnostic_logger: Option<Arc<BedrockDiagnosticLogger>>,
        messages_sent: Arc<Mutex<Vec<ConversationMessage>>>,
        tool_result_archive: Vec<ConversationMessage>,
    ) -> Result<LegacyResponseStream, BedrockError> {
        let base_model_id = strip_context_marker(model_id);
        let effective_model_id = if cross_region_inference {
            apply_cross_region_prefix(&base_model_id, &self.region)
        } else {
            base_model_id
        };

        let external_config = ExternalBedrockConfig::load();
        let caching_config = CachingConfig::from_external_config(&external_config);

        if !caching_config.enabled {
            log::info!("[bedrock] Prompt caching disabled (DISABLE_PROMPT_CACHING=1)");
        }

        log::info!(
            "[bedrock] converse_stream: model={effective_model_id}, region={}, messages={}, tools={}",
            self.region,
            messages.len(),
            tools.len()
        );

        log::info!(
            "[bedrock] Sending request payload to Bedrock:\nSystem Prompt: {:?}\nMessages: {:#?}\nTools: {:#?}",
            system_prompt,
            messages,
            tools
        );

        let converted = build_converse_request(
            messages.clone(),
            system_prompt.clone(),
            compact_summary,
            tools.clone(),
            max_tokens,
            temperature,
            None,
            None,
            caching_config,
        );

        if let Some(ref logger) = diagnostic_logger {
            logger.log_bedrock_input(
                &messages,
                &system_prompt,
                &tools,
                max_tokens,
                temperature,
                cross_region_inference,
            );
        }

        let mut request = self
            .runtime_client
            .converse_stream()
            .model_id(&effective_model_id)
            .set_system(Some(converted.system))
            .set_messages(Some(converted.messages))
            .inference_config(converted.inference_config);

        if let Some(tool_config) = converted.tool_config {
            request = request.tool_config(tool_config);
        }

        let output = request.send().await.map_err(|e| {
            let debug_msg = format!("{:?}", e);
            let display_msg = format!("{e}");
            log::error!("[bedrock] API error (display): {display_msg}");
            log::error!("[bedrock] API error (debug): {debug_msg}");
            let msg = if debug_msg.len() > display_msg.len() {
                debug_msg.clone()
            } else {
                display_msg.clone()
            };
            if let Some(ref logger) = diagnostic_logger {
                logger.log_result_fail(&msg);
                if let Some(path) = logger.dump_error_snapshot(&display_msg, &debug_msg) {
                    log::error!(
                        "[bedrock] Wrote Bedrock failure snapshot to {}",
                        path.display()
                    );
                }
            }

            super::crash_log::log_crash(
                "BedrockApiError",
                &msg,
                &effective_model_id,
                messages.len(),
                None,
            );

            if msg.contains("AccessDenied") || msg.contains("access denied") {
                BedrockError::AccessDenied(msg)
            } else if msg.contains("ThrottlingException") || msg.contains("throttl") {
                BedrockError::Throttling(msg)
            } else if msg.contains("ValidationException") || msg.contains("validation") {
                BedrockError::ValidationError(msg)
            } else if msg.contains("ResourceNotFoundException") {
                BedrockError::ModelNotFound(effective_model_id.clone())
            } else {
                BedrockError::ApiError(msg)
            }
        })?;

        log::info!("[bedrock] Stream connected successfully");
        Ok(Box::pin(bedrock_stream_to_response_events(
            output,
            task_id.to_string(),
            needs_create_task,
            user_query,
            diagnostic_logger,
            messages_sent,
            model_id.to_string(),
            tool_result_archive,
        )))
    }

    /// Performs a non-streaming converse call and collects the full response text.
    /// Used for background progressive summarization where we don't need streaming UI.
    /// Returns (response_text, input_tokens, output_tokens).
    pub async fn converse_collect(
        &self,
        model_id: &str,
        messages: Vec<ConversationMessage>,
        system_prompt: Option<String>,
        max_tokens: i32,
        cross_region_inference: bool,
    ) -> Result<(String, u32, u32), BedrockError> {
        let base_model_id = strip_context_marker(model_id);
        let effective_model_id = if cross_region_inference {
            apply_cross_region_prefix(&base_model_id, &self.region)
        } else {
            base_model_id
        };

        let external_config = ExternalBedrockConfig::load();
        let caching_config = CachingConfig::from_external_config(&external_config);

        let converted = build_converse_request(
            messages,
            system_prompt,
            None,
            vec![],
            max_tokens,
            None,
            None,
            None,
            caching_config,
        );

        let request = self
            .runtime_client
            .converse()
            .model_id(&effective_model_id)
            .set_system(Some(converted.system))
            .set_messages(Some(converted.messages))
            .inference_config(converted.inference_config);

        let output = request.send().await.map_err(|e| {
            let msg = format!("{e}");
            log::error!("[bedrock] converse_collect error: {msg}");
            BedrockError::ApiError(msg)
        })?;

        let mut response_text = String::new();
        if let Some(aws_sdk_bedrockruntime::types::ConverseOutput::Message(msg)) = output.output() {
            for block in msg.content() {
                if let aws_sdk_bedrockruntime::types::ContentBlock::Text(text) = block {
                    response_text.push_str(text);
                }
            }
        }

        let (input_tokens, output_tokens) = output
            .usage()
            .map(|u| (u.input_tokens() as u32, u.output_tokens() as u32))
            .unwrap_or((0, 0));

        Ok((response_text, input_tokens, output_tokens))
    }
}