use crate::editor_project::{current_utc_micros, map_editor_project_error};
use crate::http_error::AppError;
use crate::platform_errors::map_oss_error;
use crate::state::AppState;
use axum::http::StatusCode;
use platform_oss::{
  LegacyAssetPrefix, OssObjectAccess, OssPutObjectRequest, OssSignedGetObjectUrlRequest,
};
use serde_json::{json, Value};
use shared_contracts::assets::{
  EditorCanvasGenerationCompletionPayload, EditorCanvasGenerationPlaceholderPayload,
};
use shared_contracts::editor_agent::{
  EditorAgentAttachmentRef, EditorAgentAttachmentSource, EditorAgentConversationDetail,
  EditorAgentConversationMessagesDocument, EditorAgentConversationSummary, EditorAgentGeneratedImage,
  EditorAgentMessage, EDITOR_AGENT_MESSAGES_DOCUMENT_VERSION,
};
use shared_kernel::{normalize_optional_string, normalize_required_string};
use spacetime_client::{
  EditorAgentConversationRecord, EditorAssetLibraryRecord, EditorAssetRecord,
  EditorProjectGetRecordInput, EditorProjectRecord, EditorProjectResourceRecord,
};
use std::collections::BTreeMap;
use std::sync::{Arc, Mutex, OnceLock};
use platform_editor_agent::agent::asset::ImageId;

pub trait IntoDataKey {
    fn into_data_key(self) -> String;
}
impl IntoDataKey for EditorAgentAttachmentRef {
    fn into_data_key(self) -> String {
        self.object_key
            .as_deref()
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(|value| value.trim_start_matches('/').to_string())
            // .or_else(|| normalize_required_string(self.reference_id.as_str()))
            .unwrap_or_else(|| self.image_src.clone())
    }
}
impl IntoDataKey for EditorAgentGeneratedImage {
    fn into_data_key(self) -> String {
        self.object_key
            .as_deref()
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(|value| value.trim_start_matches('/').to_string())
            .unwrap_or(self.image_src)
    }
}
impl IntoDataKey for EditorProjectResourceRecord {
    fn into_data_key(self) -> String {
        self.object_key
            .as_deref()
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(|value| value.trim_start_matches('/').to_string())
            .unwrap_or_else(|| self.image_src.clone())
    }
}

impl IntoDataKey for EditorAssetRecord {
    fn into_data_key(self) -> String {
        self.object_key
            .as_deref()
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(|value| value.trim_start_matches('/').to_string())
            .unwrap_or_else(|| self.image_src.clone())
    }
}

pub trait IntoImageId {
    fn into_image_id(self) -> ImageId;
}
impl IntoImageId for EditorAgentAttachmentRef {
    fn into_image_id(self) -> ImageId {
        ImageId::from_data_key(self.into_data_key())
    }
}
impl IntoImageId for EditorProjectResourceRecord {
    fn into_image_id(self) -> ImageId {
        ImageId::from_data_key(self.into_data_key())
    }
}
impl IntoImageId for EditorAssetRecord {
    fn into_image_id(self) -> ImageId {
        ImageId::from_data_key(self.into_data_key())
    }
}

// TODO resource id is not traced by now
// pub trait IntoResourceId {
//     fn into_resource_id(self) -> String;
// }
//
// impl IntoResourceId for EditorProjectResourceRecord {
//     fn into_resource_id(self) -> String {
//         self.resource_id
//     }
// }
//
// impl IntoResourceId for EditorAssetRecord {
//     fn into_resource_id(self) -> String {
//         self.asset_id
//     }
// }

#[cfg(test)]
mod image_id_tests {
    use platform_editor_agent::agent::asset::ImageId;

    #[test]
    fn image_id_is_a_stable_hash_of_the_data_key() {
        let data_key = "editor-projects/proj-1/image.png";
        let image_id = ImageId::from_data_key(data_key);

        assert_eq!(image_id, ImageId::from_data_key(data_key));
        assert_ne!(image_id, ImageId::from_data_key("another-image.png"));
        assert!(image_id.id.starts_with("sha256:"));
        assert!(!image_id.id.contains(data_key));
    }
}

type EditorAgentConversationLockMap = Mutex<BTreeMap<String, Arc<tokio::sync::Mutex<()>>>>;
static EDITOR_AGENT_CONVERSATION_LOCKS: OnceLock<EditorAgentConversationLockMap> = OnceLock::new();

pub fn editor_agent_conversation_lock(conversation_id: &str) -> Arc<tokio::sync::Mutex<()>> {
    let locks = EDITOR_AGENT_CONVERSATION_LOCKS.get_or_init(|| Mutex::new(BTreeMap::new()));
    let mut locks = locks
        .lock()
        .unwrap_or_else(|poisoned| poisoned.into_inner());
    locks
        .entry(conversation_id.to_string())
        .or_insert_with(|| Arc::new(tokio::sync::Mutex::new(())))
        .clone()
}
pub fn now_rfc3339() -> String {
    shared_kernel::format_rfc3339(time::OffsetDateTime::now_utc())
        .unwrap_or_else(|_| "1970-01-01T00:00:00Z".to_string())
}

const EDITOR_AGENT_MESSAGES_DOCUMENT_MAX_BYTES: usize = 2 * 1024 * 1024;
pub async fn require_editor_agent_sidebar_enabled(
    state: &AppState,
    owner_user_id: &str,
) -> Result<(), AppError> {
    match state
        .is_image_editor_agent_sidebar_enabled_for_user(Some(owner_user_id))
        .await
    {
        Ok(true) => Ok(()),
        Ok(false) => Err(editor_agent_sidebar_unavailable()),
        Err(error) => Err(AppError::from_status(StatusCode::BAD_GATEWAY)
            .with_message("读取画布 Agent 灰度配置失败")
            .with_details(json!({
                "provider": "spacetimedb",
                "message": error.to_string(),
            }))),
    }
}

fn editor_agent_sidebar_unavailable() -> AppError {
    AppError::from_status(StatusCode::SERVICE_UNAVAILABLE)
        .with_message("画布 Agent 暂不可用")
        .with_details(json!({
            "provider": "editor-agent",
            "reason": "image_editor_agent_sidebar_disabled",
            "gateKey": module_runtime::IMAGE_EDITOR_AGENT_SIDEBAR_GATE_KEY,
        }))
}
// const EDITOR_AGENT_MESSAGES_DOCUMENT_MAX_BYTES: usize = 2 * 1024 * 1024;
pub fn editor_agent_bad_request(message: impl Into<String>) -> AppError {
    AppError::from_status(StatusCode::BAD_REQUEST).with_details(json!({
        "provider": "editor-agent",
        "message": message.into(),
    }))
}

fn editor_agent_oss_unavailable() -> AppError {
    AppError::from_status(StatusCode::SERVICE_UNAVAILABLE).with_details(json!({
        "provider": "aliyun-oss",
        "reason": "OSS is not configured for editor agent conversations",
    }))
}

fn editor_agent_oss_read_error(message: impl Into<String>) -> AppError {
    AppError::from_status(StatusCode::BAD_GATEWAY).with_details(json!({
        "provider": "aliyun-oss",
        "message": message.into(),
    }))
}

fn editor_agent_messages_document_too_large() -> AppError {
    AppError::from_status(StatusCode::PAYLOAD_TOO_LARGE).with_details(json!({
        "provider": "editor-agent",
        "message": "message document is too large",
        "maxBytes": EDITOR_AGENT_MESSAGES_DOCUMENT_MAX_BYTES,
    }))
}
pub async fn write_messages_document(
    state: &AppState,
    conversation: &EditorAgentConversationRecord,
    document: &EditorAgentConversationMessagesDocument,
) -> Result<(), AppError> {
    if document.conversation_id != conversation.conversation_id {
        return Err(
            AppError::from_status(StatusCode::BAD_REQUEST).with_details(json!({
                "provider": "editor-agent",
                "message": "message document conversationId does not match metadata",
            })),
        );
    }
    let body = serde_json::to_vec(document).map_err(|error| {
        AppError::from_status(StatusCode::INTERNAL_SERVER_ERROR).with_details(json!({
            "provider": "editor-agent",
            "message": format!("failed to serialize message document: {error}"),
        }))
    })?;
    if body.len() > EDITOR_AGENT_MESSAGES_DOCUMENT_MAX_BYTES {
        return Err(editor_agent_messages_document_too_large());
    }

    let oss_client = state
        .oss_client()
        .ok_or_else(editor_agent_oss_unavailable)?;
    let put_result = oss_client
        .put_object(
            &reqwest::Client::new(),
            OssPutObjectRequest {
                prefix: LegacyAssetPrefix::EditorAgent,
                path_segments: Vec::new(),
                file_name: format!("{}.json", conversation.conversation_id),
                content_type: Some("application/json; charset=utf-8".to_string()),
                access: OssObjectAccess::Private,
                metadata: BTreeMap::from([
                    (
                        "conversation-id".to_string(),
                        conversation.conversation_id.clone(),
                    ),
                    ("project-id".to_string(), conversation.project_id.clone()),
                    (
                        "owner-user-id".to_string(),
                        conversation.owner_user_id.clone(),
                    ),
                ]),
                body,
            },
        )
        .await
        .map_err(|error| map_oss_error(error, "aliyun-oss"))?;
    if put_result.object_key != conversation.messages_object_key {
        return Err(
            AppError::from_status(StatusCode::INTERNAL_SERVER_ERROR).with_details(json!({
                "provider": "editor-agent",
                "message": "OSS object key mismatch while writing message document",
                "expectedObjectKey": conversation.messages_object_key,
                "actualObjectKey": put_result.object_key,
            })),
        );
    }
    Ok(())
}

const EDITOR_AGENT_MESSAGES_READ_EXPIRE_SECONDS: u64 = 60;

pub async fn read_messages_document(
    state: &AppState,
    conversation: &EditorAgentConversationRecord,
) -> Result<EditorAgentConversationMessagesDocument, AppError> {
    let oss_client = state
        .oss_client()
        .ok_or_else(editor_agent_oss_unavailable)?;
    let signed = oss_client
        .sign_internal_get_object_url(OssSignedGetObjectUrlRequest {
            object_key: conversation.messages_object_key.clone(),
            expire_seconds: Some(EDITOR_AGENT_MESSAGES_READ_EXPIRE_SECONDS),
        })
        .map_err(|error| map_oss_error(error, "aliyun-oss"))?;
    let response = reqwest::Client::new()
        .get(signed.signed_url.as_str())
        .send()
        .await
        .map_err(|error| editor_agent_oss_read_error(error.to_string()))?;
    if response.status() == StatusCode::NOT_FOUND {
        return Ok(empty_messages_document(
            conversation.conversation_id.as_str(),
        ));
    }
    if !response.status().is_success() {
        return Err(editor_agent_oss_read_error(format!(
            "OSS returned non-success status {}",
            response.status().as_u16()
        )));
    }
    if response
        .content_length()
        .is_some_and(|size| size > EDITOR_AGENT_MESSAGES_DOCUMENT_MAX_BYTES as u64)
    {
        return Err(editor_agent_messages_document_too_large());
    }
    let bytes = response
        .bytes()
        .await
        .map_err(|error| editor_agent_oss_read_error(error.to_string()))?;
    if bytes.is_empty() {
        return Ok(empty_messages_document(
            conversation.conversation_id.as_str(),
        ));
    }
    if bytes.len() > EDITOR_AGENT_MESSAGES_DOCUMENT_MAX_BYTES {
        return Err(editor_agent_messages_document_too_large());
    }
    let document: EditorAgentConversationMessagesDocument = serde_json::from_slice(&bytes)
        .map_err(|error| {
            editor_agent_oss_read_error(format!("message document JSON invalid: {error}"))
        })?;
    if document.conversation_id != conversation.conversation_id {
        return Err(
            AppError::from_status(StatusCode::BAD_GATEWAY).with_details(json!({
                "provider": "editor-agent",
                "message": "message document conversationId does not match metadata",
                "conversationId": conversation.conversation_id,
                "documentConversationId": document.conversation_id,
            })),
        );
    }
    Ok(document)
}

pub async fn ensure_editor_project_access(
    state: &AppState,
    project_id: &str,
    owner_user_id: &str,
) -> Result<(), AppError> {
    state
        .spacetime_client()
        .get_editor_project(EditorProjectGetRecordInput {
            project_id: project_id.to_string(),
            owner_user_id: owner_user_id.to_string(),
        })
        .await
        .map(|_| ())
        .map_err(map_editor_project_error)
}

pub async fn normalize_editor_agent_attachments(
    state: &AppState,
    conversation: &EditorAgentConversationRecord,
    attachments: &[EditorAgentAttachmentRef],
) -> Result<Vec<EditorAgentAttachmentRef>, AppError> {
    if attachments.is_empty() {
        return Ok(Vec::new());
    }

    let needs_canvas_resources = attachments
        .iter()
        .any(|attachment| attachment.source == EditorAgentAttachmentSource::CanvasResource);
    let needs_library_assets = attachments
        .iter()
        .any(|attachment| attachment.source == EditorAgentAttachmentSource::LibraryAsset);

    let project = if needs_canvas_resources {
        Some(
            state
                .spacetime_client()
                .get_editor_project(EditorProjectGetRecordInput {
                    project_id: conversation.project_id.clone(),
                    owner_user_id: conversation.owner_user_id.clone(),
                })
                .await
                .map_err(map_editor_project_error)?,
        )
    } else {
        None
    };
    let library = if needs_library_assets {
        Some(
            state
                .spacetime_client()
                .get_editor_asset_library(conversation.owner_user_id.clone(), current_utc_micros())
                .await
                .map_err(map_editor_project_error)?,
        )
    } else {
        None
    };

    attachments
        .iter()
        .map(|attachment| {
            normalize_editor_agent_attachment(
                conversation,
                project.as_ref(),
                library.as_ref(),
                attachment,
            )
        })
        .collect()
}

fn normalize_editor_agent_attachment(
    conversation: &EditorAgentConversationRecord,
    project: Option<&EditorProjectRecord>,
    library: Option<&EditorAssetLibraryRecord>,
    attachment: &EditorAgentAttachmentRef,
) -> Result<EditorAgentAttachmentRef, AppError> {
    let reference_id = normalize_required_string(attachment.reference_id.as_str())
        .ok_or_else(|| editor_agent_bad_request("attachment.referenceId is required"))?;
    match attachment.source {
        EditorAgentAttachmentSource::CanvasResource => {
            let project = project.ok_or_else(|| {
                editor_agent_bad_request("canvas resource attachment project context missing")
            })?;
            let resource = project
                .resources
                .iter()
                .find(|resource| resource.resource_id == reference_id)
                .ok_or_else(|| {
                    editor_agent_bad_request(format!(
                        "canvas resource attachment not found in current project: {reference_id}"
                    ))
                })?;
            normalize_canvas_resource_attachment(conversation, attachment, resource)
        }
        EditorAgentAttachmentSource::LibraryAsset => {
            let library = library.ok_or_else(|| {
                editor_agent_bad_request("library asset attachment context missing")
            })?;
            let asset = library
                .assets
                .iter()
                .find(|asset| asset.asset_id == reference_id)
                .ok_or_else(|| {
                    editor_agent_bad_request(format!(
                        "library asset attachment not found for current user: {reference_id}"
                    ))
                })?;
            normalize_library_asset_attachment(attachment, asset)
        }
    }
}

pub fn normalize_canvas_resource_attachment(
    conversation: &EditorAgentConversationRecord,
    attachment: &EditorAgentAttachmentRef,
    resource: &EditorProjectResourceRecord,
) -> Result<EditorAgentAttachmentRef, AppError> {
    if resource.project_id != conversation.project_id
        || resource.owner_user_id != conversation.owner_user_id
    {
        return Err(editor_agent_bad_request(
            "canvas resource attachment does not belong to this conversation project",
        ));
    }
    validate_attachment_object_key(
        attachment.object_key.as_deref(),
        resource.object_key.as_deref(),
        resource.resource_id.as_str(),
    )?;

    Ok(EditorAgentAttachmentRef {
        source: EditorAgentAttachmentSource::CanvasResource,
        reference_id: resource.resource_id.clone(),
        object_key: resource.object_key.clone(),
        image_src: resource.image_src.clone(),
        thumbnail_src: None,
        label: normalize_optional_string(attachment.label.clone()),
        width: Some(resource.width),
        height: Some(resource.height),
    })
}

pub fn normalize_library_asset_attachment(
    attachment: &EditorAgentAttachmentRef,
    asset: &EditorAssetRecord,
) -> Result<EditorAgentAttachmentRef, AppError> {
    validate_attachment_object_key(
        attachment.object_key.as_deref(),
        asset.object_key.as_deref(),
        asset.asset_id.as_str(),
    )?;

    Ok(EditorAgentAttachmentRef {
        source: EditorAgentAttachmentSource::LibraryAsset,
        reference_id: asset.asset_id.clone(),
        object_key: asset.object_key.clone(),
        image_src: asset.image_src.clone(),
        thumbnail_src: asset.thumbnail_src.clone(),
        label: normalize_optional_string(attachment.label.clone())
            .or_else(|| Some(asset.label.clone())),
        width: Some(asset.width),
        height: Some(asset.height),
    })
}

fn validate_attachment_object_key(
    submitted_object_key: Option<&str>,
    stored_object_key: Option<&str>,
    reference_id: &str,
) -> Result<(), AppError> {
    let Some(submitted_object_key) = submitted_object_key.and_then(normalize_required_string)
    else {
        return Ok(());
    };
    let Some(stored_object_key) = stored_object_key.and_then(normalize_required_string) else {
        return Err(editor_agent_bad_request(format!(
            "attachment objectKey is not available for reference: {reference_id}"
        )));
    };
    if submitted_object_key != stored_object_key {
        return Err(editor_agent_bad_request(format!(
            "attachment objectKey does not match reference: {reference_id}"
        )));
    }
    Ok(())
}

pub fn conversation_summary_from_record(
    conversation: EditorAgentConversationRecord,
) -> EditorAgentConversationSummary {
    EditorAgentConversationSummary {
        conversation_id: conversation.conversation_id,
        project_id: conversation.project_id,
        title: conversation.title,
        updated_at: conversation.updated_at,
    }
}

pub fn conversation_detail_from_record(
    conversation: EditorAgentConversationRecord,
    messages: Vec<EditorAgentMessage>,
) -> EditorAgentConversationDetail {
    EditorAgentConversationDetail {
        conversation_id: conversation.conversation_id,
        project_id: conversation.project_id,
        title: conversation.title,
        created_at: conversation.created_at,
        updated_at: conversation.updated_at,
        messages,
    }
}

pub fn build_editor_agent_canvas_completion(
    project: &EditorProjectRecord,
    tool_name: &str,
    title: &str,
) -> EditorCanvasGenerationCompletionPayload {
    let (width, height) = editor_agent_tool_display_size(tool_name);
    let (x, y) = next_editor_agent_canvas_position(project.layers.clone(), width, height);
    EditorCanvasGenerationCompletionPayload {
        dialog_id: None,
        title: title.to_string(),
        placeholder: EditorCanvasGenerationPlaceholderPayload {
            x,
            y,
            width,
            height,
            original_width: width,
            original_height: height,
        },
    }
}

fn editor_agent_tool_display_size(tool_name: &str) -> (f64, f64) {
    match tool_name {
        "ui-design" | "generate-ui-design" => (640.0, 360.0),
        "generate-character" => (512.0, 768.0),
        _ => (512.0, 512.0),
    }
}

const EDITOR_AGENT_CANVAS_RESULT_GAP: f64 = 32.0;

fn next_editor_agent_canvas_position(
    layers: serde_json::Value,
    _width: f64,
    _height: f64,
) -> (f64, f64) {
    let mut max_right: Option<f64> = None;
    let mut min_y: Option<f64> = None;
    if let Value::Array(items) = layers {
        for item in items {
            if item.get("itemType").and_then(Value::as_str) == Some("generation-dialog") {
                continue;
            }
            let Some(x) = item.get("x").and_then(Value::as_f64) else {
                continue;
            };
            let Some(y) = item.get("y").and_then(Value::as_f64) else {
                continue;
            };
            let width = item.get("width").and_then(Value::as_f64).unwrap_or(0.0);
            if !x.is_finite() || !y.is_finite() || !width.is_finite() {
                continue;
            }
            max_right = Some(max_right.map_or(x + width, |value| value.max(x + width)));
            min_y = Some(min_y.map_or(y, |value| value.min(y)));
        }
    }
    (
        max_right.map_or(0.0, |right| right + EDITOR_AGENT_CANVAS_RESULT_GAP),
        min_y.unwrap_or(0.0),
    )
}

pub fn empty_messages_document(conversation_id: &str) -> EditorAgentConversationMessagesDocument {
    EditorAgentConversationMessagesDocument {
        version: EDITOR_AGENT_MESSAGES_DOCUMENT_VERSION,
        conversation_id: conversation_id.to_string(),
        messages: Vec::new(),
    }
}