use crate::error::{AppError, Result};
use crate::persistence::PersistenceClient;
use crate::state::AppState;
use chrono::Datelike;
use common_contracts::dtos::{CompanyProfileDto, TimeSeriesFinancialDto};
use common_contracts::messages::{CompanyProfilePersistedEvent, FetchCompanyDataCommand, FinancialsPersistedEvent};
use common_contracts::observability::TaskProgress;
use tracing::{error, info};

pub async fn handle_fetch_command(
    state: AppState,
    command: FetchCompanyDataCommand,
    publisher: async_nats::Client,
) -> Result<()> {
    info!("Handling Finnhub fetch data command.");

    state.tasks.insert(
        command.request_id,
        TaskProgress {
            request_id: command.request_id,
            task_name: format!("finnhub:{}", command.symbol),
            status: "FetchingData".to_string(),
            progress_percent: 10,
            details: "Fetching data from Finnhub".to_string(),
            started_at: chrono::Utc::now(),
        },
    );

    let provider = match state.get_provider().await {
        Some(p) => p,
        None => {
            let reason = "Execution failed: Finnhub provider is not available (misconfigured).".to_string();
            error!("{}", reason);
            if let Some(mut task) = state.tasks.get_mut(&command.request_id) {
                task.status = "Failed".to_string();
                task.details = reason.clone();
            }
            return Err(AppError::ProviderNotAvailable(reason));
        }
    };

    // 1. Fetch data via provider
    let (profile, financials): (CompanyProfileDto, Vec<TimeSeriesFinancialDto>) =
        provider.fetch_all_data(&command.symbol).await?;

    // 2. Persist
    {
        if let Some(mut task) = state.tasks.get_mut(&command.request_id) {
            task.status = "PersistingData".to_string();
            task.progress_percent = 60;
            task.details = "Persisting data to database".to_string();
        }
    }
    let persistence_client = PersistenceClient::new(state.config.data_persistence_service_url.clone());
    persistence_client.upsert_company_profile(profile).await?;
    let years_set: std::collections::BTreeSet<u16> =
        financials.iter().map(|f| f.period_date.year() as u16).collect();
    persistence_client.batch_insert_financials(financials).await?;

    // 3. Publish events
    let profile_event = CompanyProfilePersistedEvent {
        request_id: command.request_id,
        symbol: command.symbol.clone(),
    };
    publisher
        .publish(
            "events.data.company_profile_persisted".to_string(),
            serde_json::to_vec(&profile_event).unwrap().into(),
        )
        .await?;

    let financials_event = FinancialsPersistedEvent {
        request_id: command.request_id,
        symbol: command.symbol.clone(),
        years_updated: years_set.into_iter().collect(),
    };
    publisher
        .publish(
            "events.data.financials_persisted".to_string(),
            serde_json::to_vec(&financials_event).unwrap().into(),
        )
        .await?;

    // 4. Finalize
    if let Some(mut task) = state.tasks.get_mut(&command.request_id) {
        task.status = "Completed".to_string();
        task.progress_percent = 100;
        task.details = "Workflow finished successfully".to_string();
    }
    info!("Task {} completed successfully.", command.request_id);
    Ok(())
}