use axum::{extract::Path, http::StatusCode, response::{IntoResponse, Response}, routing::get, Json, Router};
use clap::Parser;
use miette::{IntoDiagnostic as _, Result};
use sea_orm::{entity::prelude::*, Database, DatabaseConnection, QueryOrder, ColumnTrait, QueryFilter, QuerySelect};
use sea_orm::sea_query::Expr;
use sea_orm_migration::MigratorTrait;
use serde::Serialize;
use std::net::SocketAddr;
use tracing::{info, warn};
use uuid::Uuid;

#[derive(Parser, Debug)]
#[command(name = "solstice-logs", version, about = "Solstice CI — Logs Service")]
struct Opts {
    /// HTTP bind address
    #[arg(long, env = "HTTP_ADDR", default_value = "0.0.0.0:8082")]
    http_addr: String,

    /// Database URL
    #[arg(long, env = "DATABASE_URL")]
    database_url: String,

    /// OTLP endpoint (e.g., http://localhost:4317)
    #[arg(long, env = "OTEL_EXPORTER_OTLP_ENDPOINT")]
    otlp: Option<String>,
}

#[derive(Clone)]
struct AppState { db: DatabaseConnection }

#[tokio::main(flavor = "multi_thread")]
async fn main() -> Result<()> {
    let _t = common::init_tracing("solstice-logs-service")?;
    let opts = Opts::parse();
    let db = Database::connect(opts.database_url).await.into_diagnostic()?;
    migration::Migrator::up(&db, None).await.into_diagnostic()?;

    let state = AppState { db };
    let router = Router::new()
        .route("/jobs/{request_id}/logs", get(list_logs))
        .route("/jobs/{request_id}/logs/{category}", get(get_logs_by_category))
        .with_state(state);

    let addr: SocketAddr = opts.http_addr.parse().expect("invalid HTTP_ADDR");
    info!(%addr, "logs-service starting");
    axum::serve(
        tokio::net::TcpListener::bind(addr).await.expect("bind"),
        router,
    )
    .await
    .into_diagnostic()
}

mod job_logs {
    use super::*;
    #[derive(Clone, Debug, PartialEq, DeriveEntityModel)]
    #[sea_orm(table_name = "job_logs")]
    pub struct Model {
        #[sea_orm(primary_key, auto_increment = false)]
        pub request_id: Uuid,
        #[sea_orm(primary_key, auto_increment = false)]
        pub seq: i64,
        pub ts: chrono::DateTime<chrono::Utc>,
        pub stderr: bool,
        pub line: String,
        pub category: String,
        pub level: Option<String>,
        pub fields: Option<String>,
        pub has_error: bool,
    }
    #[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
    pub enum Relation {}
    impl ActiveModelBehavior for ActiveModel {}
}

#[derive(Serialize, sea_orm::FromQueryResult)]
struct LogCategorySummary {
    category: String,
    count: i64,
    has_errors: bool,
    first_ts: chrono::DateTime<chrono::Utc>,
    last_ts: chrono::DateTime<chrono::Utc>,
}

async fn list_logs(Path(request_id): Path<String>, axum::extract::State(state): axum::extract::State<AppState>) -> Response {
    let Ok(id) = Uuid::parse_str(&request_id) else { return StatusCode::BAD_REQUEST.into_response(); };

    let query = job_logs::Entity::find()
        .select_only()
        .column(job_logs::Column::Category)
        .expr(Expr::col(job_logs::Column::Seq).count())
        .expr(Expr::col(job_logs::Column::Ts).min())
        .expr(Expr::col(job_logs::Column::Ts).max())
        .filter(job_logs::Column::RequestId.eq(id))
        .group_by(job_logs::Column::Category)
        .order_by_asc(job_logs::Column::Category);

    // Aggregate basic stats per category
    let tuples: miette::Result<Vec<(String, i64, chrono::DateTime<chrono::Utc>, chrono::DateTime<chrono::Utc>)>> = query
        .into_tuple()
        .all(&state.db)
        .await
        .into_diagnostic();

    // Separately fetch categories that have any error (portable across backends)
    let errs_res: miette::Result<Vec<String>> = job_logs::Entity::find()
        .select_only()
        .column(job_logs::Column::Category)
        .filter(job_logs::Column::RequestId.eq(id))
        .filter(job_logs::Column::HasError.eq(true))
        .group_by(job_logs::Column::Category)
        .into_tuple()
        .all(&state.db)
        .await
        .into_diagnostic();

    match (tuples, errs_res) {
        (Ok(rows), Ok(err_cats)) => {
            let errset: std::collections::HashSet<String> = err_cats.into_iter().collect();
            let out: Vec<LogCategorySummary> = rows
                .into_iter()
                .map(|(category, count, first_ts, last_ts)| LogCategorySummary {
                    has_errors: errset.contains(&category),
                    category,
                    count,
                    first_ts,
                    last_ts,
                })
                .collect();
            Json::<Vec<LogCategorySummary>>(out).into_response()
        }
        (Err(e), _) | (_, Err(e)) => { warn!(error = %e, request_id = %id, "failed to query log categories"); StatusCode::INTERNAL_SERVER_ERROR.into_response() }
    }
}

async fn get_logs_by_category(Path((request_id, category)): Path<(String, String)>, axum::extract::State(state): axum::extract::State<AppState>) -> Response {
    let Ok(id) = Uuid::parse_str(&request_id) else { return StatusCode::BAD_REQUEST.into_response(); };
    let rows = job_logs::Entity::find()
        .filter(job_logs::Column::RequestId.eq(id))
        .filter(job_logs::Column::Category.eq(category.clone()))
        .order_by_asc(job_logs::Column::Seq)
        .all(&state.db)
        .await
        .into_diagnostic();
    match rows {
        Ok(items) if items.is_empty() => StatusCode::NOT_FOUND.into_response(),
        Ok(items) => {
            let mut text = String::new();
            for r in items {
                if r.stderr || r.has_error || r.level.as_deref() == Some("error") {
                    text.push_str("[stderr] ");
                }
                text.push_str(&r.line);
                if !text.ends_with('\n') { text.push('\n'); }
            }
            (
                StatusCode::OK,
                [(axum::http::header::CONTENT_TYPE, "text/plain; charset=utf-8")],
                text,
            ).into_response()
        }
        Err(e) => { warn!(error = %e, request_id = %id, "failed to read logs"); StatusCode::INTERNAL_SERVER_ERROR.into_response() }
    }
}