//! Decision Workflows API endpoints.

use axum::{
    extract::{Path, State},
    http::StatusCode,
    routing::{get, post},
    Json, Router,
};
use serde::Deserialize;
use serde_json::{json, Value};
use sqlx::PgPool;
use uuid::Uuid;

use crate::auth::AuthUser;
use crate::plugins::builtin::decision_workflows::{
    WorkflowInstance, WorkflowPhase, WorkflowService, WorkflowTemplate,
};

// ============================================================================
// Request Types
// ============================================================================

#[derive(Debug, Deserialize)]
pub struct CreateTemplateRequest {
    pub name: String,
    pub description: Option<String>,
}

#[derive(Debug, Deserialize)]
pub struct AddPhaseRequest {
    pub name: String,
    pub phase_type: String,
    pub sequence_order: i32,
    pub duration_hours: i32,
    pub quorum_value: f64,
}

// ============================================================================
// Handlers
// ============================================================================

/// List workflow templates for a community
async fn list_templates(
    Path(community_id): Path<Uuid>,
    State(pool): State<PgPool>,
) -> Result<Json<Vec<WorkflowTemplate>>, (StatusCode, String)> {
    let templates = WorkflowService::list_templates(&pool, Some(community_id))
        .await
        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;

    Ok(Json(templates))
}

/// Create a new workflow template
async fn create_template(
    auth: AuthUser,
    Path(community_id): Path<Uuid>,
    State(pool): State<PgPool>,
    Json(req): Json<CreateTemplateRequest>,
) -> Result<Json<Value>, (StatusCode, String)> {
    let template_id = WorkflowService::create_template(
        &pool,
        community_id,
        &req.name,
        req.description.as_deref(),
        auth.user_id,
    )
    .await
    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;

    Ok(Json(json!({"id": template_id})))
}

/// Get phases for a template
async fn get_template_phases(
    Path(template_id): Path<Uuid>,
    State(pool): State<PgPool>,
) -> Result<Json<Vec<WorkflowPhase>>, (StatusCode, String)> {
    let phases = WorkflowService::get_template_phases(&pool, template_id)
        .await
        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;

    Ok(Json(phases))
}

/// Add a phase to a template
async fn add_phase(
    _auth: AuthUser,
    Path(template_id): Path<Uuid>,
    State(pool): State<PgPool>,
    Json(req): Json<AddPhaseRequest>,
) -> Result<Json<Value>, (StatusCode, String)> {
    let phase_id = WorkflowService::add_phase(
        &pool,
        template_id,
        &req.name,
        &req.phase_type,
        req.sequence_order,
        req.duration_hours,
        req.quorum_value,
    )
    .await
    .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;

    Ok(Json(json!({"id": phase_id})))
}

/// Get workflow for a proposal
async fn get_workflow_for_proposal(
    Path(proposal_id): Path<Uuid>,
    State(pool): State<PgPool>,
) -> Result<Json<Option<WorkflowInstance>>, (StatusCode, String)> {
    let workflow = WorkflowService::get_workflow_for_proposal(&pool, proposal_id)
        .await
        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;

    Ok(Json(workflow))
}

/// Get workflow progress
async fn get_workflow_progress(
    Path(proposal_id): Path<Uuid>,
    State(pool): State<PgPool>,
) -> Result<Json<Value>, (StatusCode, String)> {
    let progress = WorkflowService::get_workflow_progress(&pool, proposal_id)
        .await
        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;

    Ok(Json(progress))
}

/// Manually advance workflow phase
async fn advance_phase(
    auth: AuthUser,
    Path(proposal_id): Path<Uuid>,
    State(pool): State<PgPool>,
) -> Result<Json<Value>, (StatusCode, String)> {
    let success = WorkflowService::advance_phase(&pool, proposal_id, Some(auth.user_id), None)
        .await
        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;

    Ok(Json(json!({"success": success})))
}

// ============================================================================
// Router
// ============================================================================

pub fn router(pool: PgPool) -> Router {
    Router::new()
        // Templates
        .route("/api/communities/{community_id}/workflow-templates", get(list_templates).post(create_template))
        .route("/api/workflow-templates/{template_id}/phases", get(get_template_phases).post(add_phase))
        // Proposal workflows
        .route("/api/proposals/{proposal_id}/workflow", get(get_workflow_for_proposal))
        .route("/api/proposals/{proposal_id}/workflow/progress", get(get_workflow_progress))
        .route("/api/proposals/{proposal_id}/workflow/advance", post(advance_phase))
        .with_state(pool)
}