pub mod admin;
use axum::{
    extract::{Path, Query, State},
    http::StatusCode,
    response::IntoResponse,
    routing::{get, patch, post},
    Json, Router,
};
use serde::Deserialize;
use uuid::Uuid;
use db::models::company::{CompanyRepository, UpsertCompanyProfilePayload};
use db::models::job::{JobRepository, CreateJobPayload as DbCreateJobPayload, UpdateJobPayload as DbUpdateJobPayload};
use db::models::application::ApplicationRepository;
use db::models::user::UserRepository;
use contracts::auth_middleware::AuthUser;
use crate::AppState;

pub fn router() -> Router<AppState> {
    Router::new()
        .route("/profile/me", get(get_profile).patch(update_profile))
        .route("/jobs", get(list_jobs).post(create_job))
        .route("/jobs/{id}", get(get_job).patch(update_job))
        .route("/jobs/{id}/submit", post(submit_job))
        .route("/jobs/{id}/close", post(close_job))
        .route("/jobs/{id}/applications", get(list_applications))
        .route("/applications/{id}/status", patch(update_application_status))
        .route("/applications/{id}/contact", get(view_contact))
}

#[derive(Deserialize)]
pub struct PaginationQuery {
    pub page: Option<i64>,
    pub limit: Option<i64>,
    pub status: Option<String>,
}

#[derive(Deserialize)]
pub struct CreateJobRequest {
    pub title: String,
    pub description: String,
    pub location: String,
    pub job_type: Option<String>,
    pub salary_min: Option<i32>,
    pub salary_max: Option<i32>,
    pub experience_years: Option<i32>,
    pub skills: Option<Vec<String>>,
    pub category: Option<String>,
}

#[derive(Deserialize)]
pub struct UpdateApplicationStatusPayload {
    pub status: String,
}

async fn get_profile(
    State(state): State<AppState>,
    auth: AuthUser,
) -> impl IntoResponse {
    match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(profile)) => (StatusCode::OK, Json(profile)).into_response(),
        Ok(None) => (StatusCode::NOT_FOUND, "Company profile not found").into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn update_profile(
    State(state): State<AppState>,
    auth: AuthUser,
    Json(payload): Json<UpsertCompanyProfilePayload>,
) -> impl IntoResponse {
    match CompanyRepository::upsert(&state.pool, auth.user_id, payload).await {
        Ok(profile) => (StatusCode::OK, Json(profile)).into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn list_jobs(
    State(state): State<AppState>,
    auth: AuthUser,
    Query(q): Query<PaginationQuery>,
) -> impl IntoResponse {
    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::NOT_FOUND, "Company not found").into_response(),
    };

    let page = q.page.unwrap_or(1);
    let limit = q.limit.unwrap_or(20);
    match JobRepository::list_by_company_id(&state.pool, company.id, q.status, page, limit).await {
        Ok(jobs) => (StatusCode::OK, Json(serde_json::json!({
            "data": jobs,
            "pagination": { "page": page, "limit": limit }
        }))).into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn create_job(
    State(state): State<AppState>,
    auth: AuthUser,
    Json(payload): Json<CreateJobRequest>,
) -> impl IntoResponse {
    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::NOT_FOUND, "Company not found").into_response(),
    };

    if company.status != "APPROVED" {
        return (StatusCode::FORBIDDEN, "Company profile approval is required before posting jobs").into_response();
    }

    // --- New Quota Logic ---
    let jobs_this_month = match JobRepository::count_by_company_id_this_month(&state.pool, company.id).await {
        Ok(count) => count,
        Err(e) => return (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    };

    if jobs_this_month >= 1 {
        // Must use a purchased slot if they've already used their monthly freebie
        if company.purchased_job_slots <= 0 {
            return (
                StatusCode::PAYMENT_REQUIRED,
                Json(serde_json::json!({
                    "error": "Monthly free job quota exhausted. Please purchase job slots.",
                    "code": "QUOTA_EXHAUSTED",
                    "requires_tracecoins": true
                }))
            ).into_response();
        }

        // Deduct ONE purchased slot
        let deduct_result = sqlx::query!(
            "UPDATE company_profiles SET purchased_job_slots = purchased_job_slots - 1 WHERE id = $1",
            company.id
        )
        .execute(&state.pool)
        .await;

        if let Err(e) = deduct_result {
            tracing::error!("Failed to deduct job slot: {}", e);
            return (StatusCode::INTERNAL_SERVER_ERROR, "Failed to deduct quota").into_response();
        }
    }
    // -----------------------

    let db_payload = DbCreateJobPayload {
        company_id: company.id,
        title: payload.title,
        category: payload.category,
        description: payload.description,
        location: payload.location,
        job_type: payload.job_type,
        salary_min: payload.salary_min,
        salary_max: payload.salary_max,
        experience_years: payload.experience_years,
        skills: payload.skills,
    };

    match JobRepository::create(&state.pool, db_payload).await {
        Ok(job) => (StatusCode::CREATED, Json(job)).into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn get_job(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
    _auth: AuthUser,
) -> impl IntoResponse {
    match JobRepository::get_by_id(&state.pool, id).await {
        Ok(Some(job)) => (StatusCode::OK, Json(job)).into_response(),
        Ok(None) => (StatusCode::NOT_FOUND, "Job not found").into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn update_job(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
    auth: AuthUser,
    Json(payload): Json<DbUpdateJobPayload>,
) -> impl IntoResponse {
    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::NOT_FOUND, "Company not found").into_response(),
    };

    if company.status != "APPROVED" {
        return (StatusCode::FORBIDDEN, "Company profile approval is required before submitting jobs").into_response();
    }

    let job = match JobRepository::get_by_id(&state.pool, id).await {
        Ok(Some(j)) if j.company_id == company.id => j,
        Ok(Some(_)) => return (StatusCode::FORBIDDEN, "Access denied").into_response(),
        _ => return (StatusCode::NOT_FOUND, "Job not found").into_response(),
    };

    match JobRepository::update(&state.pool, job.id, payload).await {
        Ok(updated) => (StatusCode::OK, Json(updated)).into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn submit_job(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
    auth: AuthUser,
) -> impl IntoResponse {
    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::NOT_FOUND, "Company not found").into_response(),
    };

    let job = match JobRepository::get_by_id(&state.pool, id).await {
        Ok(Some(j)) if j.company_id == company.id => j,
        Ok(Some(_)) => return (StatusCode::FORBIDDEN, "Access denied").into_response(),
        _ => return (StatusCode::NOT_FOUND, "Job not found").into_response(),
    };

    if job.status != "DRAFT" {
        return (StatusCode::BAD_REQUEST, "Job already submitted or live").into_response();
    }

    match JobRepository::update_status(&state.pool, job.id, "PENDING_APPROVAL").await {
        Ok(updated) => {
            // Fire email to company user (ignore failures)
            if let Ok(user) = UserRepository::get_by_id(&state.pool, auth.user_id).await {
                let _ = state.mail.send_job_submitted_email(&user.email, user.full_name.as_deref().unwrap_or("User"), &updated.title).await;
            }
            (StatusCode::OK, Json(updated)).into_response()
        }
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn close_job(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
    auth: AuthUser,
) -> impl IntoResponse {
    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::NOT_FOUND, "Company not found").into_response(),
    };

    let job = match JobRepository::get_by_id(&state.pool, id).await {
        Ok(Some(j)) if j.company_id == company.id => j,
        Ok(Some(_)) => return (StatusCode::FORBIDDEN, "Access denied").into_response(),
        _ => return (StatusCode::NOT_FOUND, "Job not found").into_response(),
    };

    match JobRepository::update_status(&state.pool, job.id, "CLOSED").await {
        Ok(updated) => (StatusCode::OK, Json(updated)).into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn list_applications(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
    auth: AuthUser,
    Query(q): Query<PaginationQuery>,
) -> impl IntoResponse {
    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::NOT_FOUND, "Company not found").into_response(),
    };

    let job = match JobRepository::get_by_id(&state.pool, id).await {
        Ok(Some(j)) if j.company_id == company.id => j,
        Ok(Some(_)) => return (StatusCode::FORBIDDEN, "Access denied").into_response(),
        _ => return (StatusCode::NOT_FOUND, "Job not found").into_response(),
    };

    let page = q.page.unwrap_or(1);
    let limit = q.limit.unwrap_or(20);
    match ApplicationRepository::list_by_job_id(&state.pool, job.id, q.status, page, limit).await {
        Ok(apps) => (StatusCode::OK, Json(serde_json::json!({
            "data": apps,
            "pagination": { "page": page, "limit": limit }
        }))).into_response(),
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn update_application_status(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
    auth: AuthUser,
    Json(payload): Json<UpdateApplicationStatusPayload>,
) -> impl IntoResponse {
    let app = match ApplicationRepository::get_by_id(&state.pool, id).await {
        Ok(Some(a)) => a,
        _ => return (StatusCode::NOT_FOUND, "Application not found").into_response(),
    };

    let job = match JobRepository::get_by_id(&state.pool, app.job_id).await {
        Ok(Some(j)) => j,
        _ => return (StatusCode::INTERNAL_SERVER_ERROR, "Job lost").into_response(),
    };

    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::FORBIDDEN, "Access denied").into_response(),
    };

    if job.company_id != company.id {
        return (StatusCode::FORBIDDEN, "Access denied").into_response();
    }

    match ApplicationRepository::update_status(&state.pool, app.id, &payload.status).await {
        Ok(updated) => {
            // Notify applicant of status change (ignore failures)
            let applicant_info = sqlx::query_as::<_, (String, String)>(
                "SELECT u.full_name, u.email FROM users u INNER JOIN job_seekers js ON js.user_id = u.id WHERE js.id = $1",
            )
            .bind(app.job_seeker_id)
            .fetch_optional(&state.pool)
            .await;
            if let Ok(Some((name, email))) = applicant_info {
                let _ = state.mail.send_application_status_email(&email, &name, &job.title, &payload.status).await;
            }
            (StatusCode::OK, Json(updated)).into_response()
        }
        Err(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response(),
    }
}

async fn view_contact(
    State(state): State<AppState>,
    Path(id): Path<Uuid>,
    auth: AuthUser,
) -> impl IntoResponse {
    let app = match ApplicationRepository::get_by_id(&state.pool, id).await {
        Ok(Some(a)) => a,
        _ => return (StatusCode::NOT_FOUND, "Application not found").into_response(),
    };

    let job = match JobRepository::get_by_id(&state.pool, app.job_id).await {
        Ok(Some(j)) => j,
        _ => return (StatusCode::INTERNAL_SERVER_ERROR, "Job lost").into_response(),
    };

    let company = match CompanyRepository::get_by_user_id(&state.pool, auth.user_id).await {
        Ok(Some(c)) => c,
        _ => return (StatusCode::FORBIDDEN, "Access denied").into_response(),
    };

    if job.company_id != company.id {
        return (StatusCode::FORBIDDEN, "Access denied").into_response();
    }

    // If contact was already viewed for this application, return info without deducting again
    if !app.contact_viewed {
        let total_remaining = company.free_contact_views + company.purchased_contact_views;
        if total_remaining <= 0 {
            return (
                StatusCode::PAYMENT_REQUIRED,
                Json(serde_json::json!({
                    "error": "Contact view quota exhausted. Please purchase a package.",
                    "code": "QUOTA_EXHAUSTED"
                })),
            )
                .into_response();
        }

        // Deduct from free views first, then purchased
        let sql = if company.free_contact_views > 0 {
            "UPDATE companies SET free_contact_views = free_contact_views - 1 WHERE id = $1"
        } else {
            "UPDATE companies SET purchased_contact_views = purchased_contact_views - 1 WHERE id = $1"
        };

        if let Err(e) = sqlx::query(sql).bind(company.id).execute(&state.pool).await {
            tracing::error!("Failed to deduct contact view quota: {}", e);
            return (StatusCode::INTERNAL_SERVER_ERROR, "Failed to deduct quota").into_response();
        }

        if let Err(e) = ApplicationRepository::mark_contact_viewed(&state.pool, app.id).await {
            tracing::error!("Failed to mark contact viewed: {}", e);
        }
    }

    // Fetch job seeker contact info via job_seeker_id → job_seekers.user_id → users
    let contact = sqlx::query_as::<_, (Option<String>, String, Option<String>)>(
        r#"
        SELECT u.full_name, u.email, u.phone
        FROM users u
        INNER JOIN job_seekers js ON js.user_id = u.id
        WHERE js.id = $1
        "#,
    )
    .bind(app.job_seeker_id)
    .fetch_optional(&state.pool)
    .await;

    match contact {
        Ok(Some((full_name, email, phone))) => {
            // Fetch updated quota to return to client
            let updated_company = CompanyRepository::get_by_user_id(&state.pool, auth.user_id)
                .await
                .ok()
                .flatten();
            let (free_remaining, purchased_remaining) = updated_company
                .map(|c| (c.free_contact_views, c.purchased_contact_views))
                .unwrap_or((0, 0));

            (StatusCode::OK, Json(serde_json::json!({
                "application_id": id,
                "full_name": full_name,
                "email": email,
                "phone": phone,
                "quota": {
                    "free_remaining": free_remaining,
                    "purchased_remaining": purchased_remaining,
                    "total_remaining": free_remaining + purchased_remaining
                }
            })))
                .into_response()
        }
        Ok(None) => (StatusCode::NOT_FOUND, "Applicant not found").into_response(),
        Err(e) => {
            tracing::error!("Failed to fetch applicant contact: {}", e);
            (StatusCode::INTERNAL_SERVER_ERROR, "Failed to fetch contact info").into_response()
        }
    }
}