//! HTTP handlers for the server-side persona store.
//!
//! Personas previously lived only in mobile AsyncStorage; this module
//! elevates them so they can sync across devices and so the
//! `entity_facts.persona_id` column has something to reference.
//!
//! Built-in personas (default / journal / factual) are seeded by the
//! migration. Customs are created here and may be migrated up from a
//! device's local store via `POST /personas/migrate`.

use actix_web::dev::{ServiceFactory, ServiceRequest};
use actix_web::{App, HttpResponse, Responder, web};
use serde::{Deserialize, Serialize};
use std::sync::Mutex;

use crate::data::Claims;
use crate::database::models::Persona;
use crate::database::{ImportPersona, PersonaDao, PersonaPatch};

// ---------------------------------------------------------------------------
// Wire shapes — camelCase out the door, snake_case from the DB.
// ---------------------------------------------------------------------------

#[derive(Serialize)]
pub struct PersonaView {
    pub id: String,
    pub name: String,
    #[serde(rename = "systemPrompt")]
    pub system_prompt: String,
    #[serde(rename = "isBuiltIn")]
    pub is_built_in: bool,
    #[serde(rename = "includeAllMemories")]
    pub include_all_memories: bool,
    #[serde(rename = "createdAt")]
    pub created_at: i64,
    #[serde(rename = "updatedAt")]
    pub updated_at: i64,
    /// "Strict mode" — when true, the agent's recall_* tools return
    /// only facts whose status is 'reviewed'. See migration
    /// 2026-05-10-000400.
    #[serde(rename = "reviewedOnlyFacts")]
    pub reviewed_only_facts: bool,
}

impl From<Persona> for PersonaView {
    fn from(p: Persona) -> Self {
        Self {
            id: p.persona_id,
            name: p.name,
            system_prompt: p.system_prompt,
            is_built_in: p.is_built_in,
            include_all_memories: p.include_all_memories,
            created_at: p.created_at,
            updated_at: p.updated_at,
            reviewed_only_facts: p.reviewed_only_facts,
        }
    }
}

#[derive(Deserialize)]
pub struct CreatePersonaRequest {
    pub name: String,
    #[serde(rename = "systemPrompt")]
    pub system_prompt: String,
    /// Optional caller-provided id. When present (e.g. a client that
    /// already minted `"custom-1735124234"` locally and is upgrading from
    /// the AsyncStorage-only era), the server uses it; collisions return
    /// 409. When absent the server mints `"custom-<ms>"`.
    #[serde(default, rename = "personaId")]
    pub persona_id: Option<String>,
}

#[derive(Deserialize)]
pub struct UpdatePersonaRequest {
    #[serde(default)]
    pub name: Option<String>,
    #[serde(default, rename = "systemPrompt")]
    pub system_prompt: Option<String>,
    #[serde(default, rename = "includeAllMemories")]
    pub include_all_memories: Option<bool>,
    #[serde(default, rename = "reviewedOnlyFacts")]
    pub reviewed_only_facts: Option<bool>,
}

#[derive(Deserialize)]
pub struct MigrateRequest {
    pub personas: Vec<MigratePersona>,
}

#[derive(Deserialize)]
pub struct MigratePersona {
    pub id: String,
    pub name: String,
    #[serde(rename = "systemPrompt")]
    pub system_prompt: String,
    #[serde(default, rename = "isBuiltIn")]
    pub is_built_in: bool,
    #[serde(default, rename = "createdAt")]
    pub created_at: Option<i64>,
}

#[derive(Serialize)]
pub struct MigrateResponse {
    pub inserted: usize,
}

// ---------------------------------------------------------------------------
// Service registration
// ---------------------------------------------------------------------------

pub type PersonaDaoData = web::Data<Mutex<Box<dyn PersonaDao>>>;

pub fn add_persona_services<T>(app: App<T>) -> App<T>
where
    T: ServiceFactory<ServiceRequest, Config = (), Error = actix_web::Error, InitError = ()>,
{
    app.service(
        web::scope("/personas")
            .service(web::resource("/migrate").route(web::post().to(migrate_personas)))
            .service(
                web::resource("")
                    .route(web::get().to(list_personas))
                    .route(web::post().to(create_persona)),
            )
            .service(
                web::resource("/{persona_id}")
                    .route(web::put().to(update_persona))
                    .route(web::delete().to(delete_persona)),
            ),
    )
}

// ---------------------------------------------------------------------------
// Handlers
// ---------------------------------------------------------------------------

fn user_id_from_claims(claims: &Claims) -> Option<i32> {
    claims.sub.parse::<i32>().ok()
}

async fn list_personas(claims: Claims, dao: PersonaDaoData) -> impl Responder {
    let Some(uid) = user_id_from_claims(&claims) else {
        return HttpResponse::Unauthorized().json(serde_json::json!({"error": "Invalid claims"}));
    };
    let cx = opentelemetry::Context::current();
    let mut dao = dao.lock().expect("Unable to lock PersonaDao");
    match dao.list_personas(&cx, uid) {
        Ok(rows) => {
            let views: Vec<PersonaView> = rows.into_iter().map(PersonaView::from).collect();
            HttpResponse::Ok().json(views)
        }
        Err(e) => {
            log::error!("list_personas error: {:?}", e);
            HttpResponse::InternalServerError().json(serde_json::json!({"error": "Database error"}))
        }
    }
}

async fn create_persona(
    claims: Claims,
    body: web::Json<CreatePersonaRequest>,
    dao: PersonaDaoData,
) -> impl Responder {
    let Some(uid) = user_id_from_claims(&claims) else {
        return HttpResponse::Unauthorized().json(serde_json::json!({"error": "Invalid claims"}));
    };

    if body.name.trim().is_empty() {
        return HttpResponse::BadRequest().json(serde_json::json!({"error": "name is required"}));
    }
    if body.system_prompt.trim().is_empty() {
        return HttpResponse::BadRequest()
            .json(serde_json::json!({"error": "systemPrompt is required"}));
    }

    let cx = opentelemetry::Context::current();
    let mut dao = dao.lock().expect("Unable to lock PersonaDao");

    let pid = match body.persona_id.as_deref() {
        Some(s) if !s.trim().is_empty() => s.to_string(),
        _ => format!("custom-{}", chrono::Utc::now().timestamp_millis()),
    };

    if matches!(pid.as_str(), "default" | "journal" | "factual") {
        return HttpResponse::Conflict()
            .json(serde_json::json!({"error": "persona id collides with a built-in"}));
    }

    // Pre-check existence so we can return 409 cleanly. The DB UNIQUE
    // would also catch it, but parsing Diesel's "constraint violation"
    // out of a generic DbError is uglier than a quick lookup.
    if let Ok(Some(_)) = dao.get_persona(&cx, uid, &pid) {
        return HttpResponse::Conflict()
            .json(serde_json::json!({"error": "persona already exists"}));
    }

    match dao.create_persona(
        &cx,
        uid,
        &pid,
        &body.name,
        &body.system_prompt,
        false,
        false,
    ) {
        Ok(p) => HttpResponse::Created().json(PersonaView::from(p)),
        Err(e) => {
            log::error!("create_persona error: {:?}", e);
            HttpResponse::InternalServerError().json(serde_json::json!({"error": "Database error"}))
        }
    }
}

async fn update_persona(
    claims: Claims,
    path: web::Path<String>,
    body: web::Json<UpdatePersonaRequest>,
    dao: PersonaDaoData,
) -> impl Responder {
    let Some(uid) = user_id_from_claims(&claims) else {
        return HttpResponse::Unauthorized().json(serde_json::json!({"error": "Invalid claims"}));
    };
    let pid = path.into_inner();
    let cx = opentelemetry::Context::current();
    let mut dao = dao.lock().expect("Unable to lock PersonaDao");

    // Built-in personas are owned by the migration; the canonical voice
    // text lives in source. A client renaming or rewriting the prompt
    // here would diverge from what new users get seeded with and hide
    // the operator's actual customization (their own custom persona)
    // from the picker. `include_all_memories` stays editable on
    // built-ins — that's a per-user preference, not the persona's
    // identity. Mirrors the same guard delete_persona enforces below.
    match dao.get_persona(&cx, uid, &pid) {
        Ok(Some(p)) if p.is_built_in => {
            let editing_identity =
                body.name.is_some() || body.system_prompt.is_some();
            if editing_identity {
                return HttpResponse::Conflict().json(serde_json::json!({
                    "error": "Cannot edit name or systemPrompt of a built-in persona"
                }));
            }
        }
        Ok(None) => {
            return HttpResponse::NotFound()
                .json(serde_json::json!({"error": "Persona not found"}));
        }
        Err(e) => {
            log::error!("update_persona lookup error: {:?}", e);
            return HttpResponse::InternalServerError()
                .json(serde_json::json!({"error": "Database error"}));
        }
        Ok(Some(_)) => {}
    }

    let patch = PersonaPatch {
        name: body.name.clone(),
        system_prompt: body.system_prompt.clone(),
        include_all_memories: body.include_all_memories,
        reviewed_only_facts: body.reviewed_only_facts,
    };
    match dao.update_persona(&cx, uid, &pid, patch) {
        Ok(Some(p)) => HttpResponse::Ok().json(PersonaView::from(p)),
        Ok(None) => {
            HttpResponse::NotFound().json(serde_json::json!({"error": "Persona not found"}))
        }
        Err(e) => {
            log::error!("update_persona error: {:?}", e);
            HttpResponse::InternalServerError().json(serde_json::json!({"error": "Database error"}))
        }
    }
}

async fn delete_persona(
    claims: Claims,
    path: web::Path<String>,
    dao: PersonaDaoData,
) -> impl Responder {
    let Some(uid) = user_id_from_claims(&claims) else {
        return HttpResponse::Unauthorized().json(serde_json::json!({"error": "Invalid claims"}));
    };
    let pid = path.into_inner();
    let cx = opentelemetry::Context::current();
    let mut dao = dao.lock().expect("Unable to lock PersonaDao");

    match dao.get_persona(&cx, uid, &pid) {
        Ok(Some(p)) if p.is_built_in => {
            return HttpResponse::Conflict()
                .json(serde_json::json!({"error": "Cannot delete built-in persona"}));
        }
        Ok(None) => {
            return HttpResponse::NotFound()
                .json(serde_json::json!({"error": "Persona not found"}));
        }
        Err(e) => {
            log::error!("delete_persona lookup error: {:?}", e);
            return HttpResponse::InternalServerError()
                .json(serde_json::json!({"error": "Database error"}));
        }
        Ok(Some(_)) => {}
    }

    match dao.delete_persona(&cx, uid, &pid) {
        Ok(_) => HttpResponse::NoContent().finish(),
        Err(e) => {
            log::error!("delete_persona error: {:?}", e);
            HttpResponse::InternalServerError().json(serde_json::json!({"error": "Database error"}))
        }
    }
}

async fn migrate_personas(
    claims: Claims,
    body: web::Json<MigrateRequest>,
    dao: PersonaDaoData,
) -> impl Responder {
    let Some(uid) = user_id_from_claims(&claims) else {
        return HttpResponse::Unauthorized().json(serde_json::json!({"error": "Invalid claims"}));
    };
    let cx = opentelemetry::Context::current();
    let mut dao = dao.lock().expect("Unable to lock PersonaDao");

    // Filter out built-in ids — those are already seeded by the
    // migration and re-importing them would be a no-op anyway thanks to
    // INSERT OR IGNORE, but skipping early avoids the UNIQUE round-trip.
    let now = chrono::Utc::now().timestamp_millis();
    let rows: Vec<ImportPersona> = body
        .personas
        .iter()
        .filter(|p| !matches!(p.id.as_str(), "default" | "journal" | "factual"))
        .map(|p| ImportPersona {
            persona_id: p.id.clone(),
            name: p.name.clone(),
            system_prompt: p.system_prompt.clone(),
            is_built_in: p.is_built_in,
            created_at: p.created_at.unwrap_or(now),
        })
        .collect();

    match dao.bulk_import(&cx, uid, &rows) {
        Ok(inserted) => HttpResponse::Ok().json(MigrateResponse { inserted }),
        Err(e) => {
            log::error!("migrate_personas error: {:?}", e);
            HttpResponse::InternalServerError().json(serde_json::json!({"error": "Database error"}))
        }
    }
}