use std::time::Duration;

use ai::sync::{UpstreamModel, UpstreamPricing};
use ai::client::EndpointConfig;
use chrono::Utc;
use db::sqlx::{self, types::Decimal};
use model::ai::{AiModelModel, AiModelVersionModel, AiProviderModel};
use serde::Serialize;
use tokio::time::interval;
use utoipa::ToSchema;
use uuid::Uuid;

use crate::{AppService, error::AppError};

#[derive(Debug, Clone, Serialize, ToSchema)]
pub struct SyncModelsResponse {
    pub models_created: i64,
    pub models_updated: i64,
    pub models_offline: i64,
    pub models_deactivated: i64,
    pub versions_created: i64,
    pub pricing_created: i64,
    pub pricing_updated: i64,
}

#[derive(Debug, Clone)]
pub struct SyncResult {
    pub provider_id: Uuid,
    pub provider_name: String,
    pub total: u32,
    pub synced: u32,
    pub skipped: u32,
}

fn extract_provider_name(model: &UpstreamModel) -> String {
    if let Some(owned) = &model.owned_by {
        if !owned.is_empty() {
            return normalize_provider_name(owned);
        }
    }
    normalize_provider_name(model.id.split('/').next().unwrap_or("unknown"))
}

fn normalize_provider_name(slug: &str) -> String {
    match slug {
        "openai" => "openai",
        "anthropic" => "anthropic",
        "google" | "google-ai" => "google",
        "mistralai" => "mistral",
        "meta-llama" | "meta" => "meta",
        "deepseek" => "deepseek",
        "azure" | "azure-openai" => "azure",
        "x-ai" | "xai" => "xai",
        "moonshot" => "moonshot",
        "alibaba" | "qwen" => "qwen",
        s => s,
    }
    .to_string()
}

fn provider_display_name(name: &str) -> String {
    match name {
        "openai" => "OpenAI",
        "anthropic" => "Anthropic",
        "google" => "Google DeepMind",
        "mistral" => "Mistral AI",
        "meta" => "Meta",
        "deepseek" => "DeepSeek",
        "azure" => "Microsoft Azure",
        "xai" => "xAI",
        "moonshot" => "Moonshot AI",
        "qwen" => "Alibaba Qwen",
        s => s,
    }
    .to_string()
}

fn infer_modality(model: &UpstreamModel) -> &'static str {
    if let Some(caps) = &model.capabilities {
        if caps.vision == Some(true) {
            return "multimodal";
        }
    }
    let lower = model.id.to_lowercase();
    if lower.contains("vision")
        || lower.contains("dall-e")
        || lower.contains("gpt-image")
        || lower.contains("gpt-4o")
    {
        "multimodal"
    } else if lower.contains("embedding") {
        "text"
    } else if lower.contains("whisper") || lower.contains("audio") {
        "audio"
    } else {
        "text"
    }
}

async fn upsert_provider(
    db: &db::AppDatabase,
    slug: &str,
) -> Result<AiProviderModel, AppError> {
    let _display = provider_display_name(slug);
    let now = Utc::now();

    if let Some(existing) = sqlx::query_as::<_, AiProviderModel>(
        "SELECT id, name, base_url, website_url, logo_url, enabled, created_at, updated_at \
         FROM ai_provider WHERE name = $1",
    )
    .bind(slug)
    .fetch_optional(db.reader())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?
    {
        sqlx::query(
            "UPDATE ai_provider SET updated_at = $1 WHERE id = $2",
        )
        .bind(now)
        .bind(existing.id)
        .execute(db.writer())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;
        Ok(existing)
    } else {
        let id = Uuid::now_v7();
        sqlx::query(
            "INSERT INTO ai_provider (id, name, enabled, created_at, updated_at) \
             VALUES ($1, $2, true, $3, $3)",
        )
        .bind(id)
        .bind(slug)
        .bind(now)
        .execute(db.writer())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        Ok(AiProviderModel {
            id,
            name: slug.to_string(),
            base_url: None,
            website_url: None,
            logo_url: None,
            enabled: true,
            created_at: now,
            updated_at: now,
        })
    }
}

async fn upsert_model(
    db: &db::AppDatabase,
    provider_id: Uuid,
    model: &UpstreamModel,
) -> Result<(AiModelModel, bool), AppError> {
    let now = Utc::now();
    let name = &model.id;
    let modality = infer_modality(model);
    let ctx = model.context_length.map(|c| c as i32);
    let max_out = model.max_output_tokens.map(|v| v as i32);

    if let Some(existing) = sqlx::query_as::<_, AiModelModel>(
        "SELECT id, provider, name, display_name, description, modality, \
         context_window, input_token_limit, output_token_limit, \
         enabled, public, created_at, updated_at, deleted_at \
         FROM ai_model WHERE name = $1 AND deleted_at IS NULL",
    )
    .bind(name)
    .fetch_optional(db.reader())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?
    {
        sqlx::query(
            "UPDATE ai_model SET provider = $1, context_window = $2, \
             output_token_limit = $3, enabled = true, updated_at = $4 \
             WHERE id = $5",
        )
        .bind(provider_id)
        .bind(ctx)
        .bind(max_out)
        .bind(now)
        .bind(existing.id)
        .execute(db.writer())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        Ok((existing, false))
    } else {
        let id = Uuid::now_v7();
        sqlx::query(
            "INSERT INTO ai_model (id, provider, name, display_name, modality, \
             context_window, input_token_limit, output_token_limit, enabled, \
             public, created_at, updated_at) \
             VALUES ($1, $2, $3, $4, $5, $6, $7, $8, true, true, $9, $9)",
        )
        .bind(id)
        .bind(provider_id)
        .bind(name)
        .bind(name)
        .bind(modality)
        .bind(ctx)
        .bind(ctx)
        .bind(max_out)
        .bind(now)
        .execute(db.writer())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        let inserted = sqlx::query_as::<_, AiModelModel>(
            "SELECT id, provider, name, display_name, description, modality, \
             context_window, input_token_limit, output_token_limit, \
             enabled, public, created_at, updated_at, deleted_at \
             FROM ai_model WHERE id = $1",
        )
        .bind(id)
        .fetch_one(db.reader())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        Ok((inserted, true))
    }
}

async fn upsert_version(
    db: &db::AppDatabase,
    model_id: Uuid,
    provider_model_name: &str,
) -> Result<(AiModelVersionModel, bool), AppError> {
    let now = Utc::now();

    if let Some(existing) = sqlx::query_as::<_, AiModelVersionModel>(
        "SELECT id, model, version, provider_model_name, \
         input_price_per_million, output_price_per_million, cached_input_price_per_million, \
         training_cutoff, released_at, deprecated_at, enabled, created_at, updated_at \
         FROM ai_model_version WHERE model = $1 AND provider_model_name = $2",
    )
    .bind(model_id)
    .bind(provider_model_name)
    .fetch_optional(db.reader())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?
    {
        Ok((existing, false))
    } else {
        let id = Uuid::now_v7();
        sqlx::query(
            "INSERT INTO ai_model_version (id, model, version, provider_model_name, \
             enabled, created_at, updated_at) \
             VALUES ($1, $2, 'latest', $3, true, $4, $4)",
        )
        .bind(id)
        .bind(model_id)
        .bind(provider_model_name)
        .bind(now)
        .execute(db.writer())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        let inserted = sqlx::query_as::<_, AiModelVersionModel>(
            "SELECT id, model, version, provider_model_name, \
             input_price_per_million, output_price_per_million, cached_input_price_per_million, \
             training_cutoff, released_at, deprecated_at, enabled, created_at, updated_at \
             FROM ai_model_version WHERE id = $1",
        )
        .bind(id)
        .fetch_one(db.reader())
        .await
        .map_err(|e| AppError::DatabaseError(e.to_string()))?;

        Ok((inserted, true))
    }
}

async fn upsert_pricing(
    db: &db::AppDatabase,
    version_id: Uuid,
    pricing: Option<&UpstreamPricing>,
) -> Result<PricingResult, AppError> {
    let Some(p) = pricing else {
        return Ok(PricingResult::Skipped);
    };
    let input_million: Option<Decimal> = p.prompt.as_deref().and_then(parse_token_price_decimal)
        .map(|per_token| per_token * Decimal::from(1_000_000u64))
        .or_else(|| {
            p.input
                .filter(|v| *v > 0.0)
                .map(|v| Decimal::try_from(v).unwrap_or_default())
        });

    let output_million: Option<Decimal> = p.completion.as_deref().and_then(parse_token_price_decimal)
        .map(|per_token| per_token * Decimal::from(1_000_000u64))
        .or_else(|| {
            p.output
                .filter(|v| *v > 0.0)
                .map(|v| Decimal::try_from(v).unwrap_or_default())
        });

    let cache_input: Option<Decimal> = p.cache_read
        .filter(|v| *v > 0.0)
        .map(|v| Decimal::try_from(v).unwrap_or_default());

    if input_million.is_none() && output_million.is_none() {
        return Ok(PricingResult::Skipped);
    }

    let existing = sqlx::query_scalar::<_, Uuid>(
        "SELECT id FROM ai_model_version WHERE id = $1",
    )
    .bind(version_id)
    .fetch_optional(db.reader())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?;

    if existing.is_none() {
        return Ok(PricingResult::Skipped);
    }

    let count = sqlx::query_scalar::<_, i64>(
        "SELECT COUNT(*) FROM ai_model_version \
         WHERE id = $1 AND input_price_per_million IS NOT NULL",
    )
    .bind(version_id)
    .fetch_one(db.reader())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?;

    sqlx::query(
        "UPDATE ai_model_version SET \
         input_price_per_million = COALESCE($1, input_price_per_million), \
         output_price_per_million = COALESCE($2, output_price_per_million), \
         cached_input_price_per_million = COALESCE($3, cached_input_price_per_million), \
         updated_at = $4 \
         WHERE id = $5",
    )
    .bind(&input_million)
    .bind(&output_million)
    .bind(&cache_input)
    .bind(Utc::now())
    .bind(version_id)
    .execute(db.writer())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?;

    if count > 0 {
        Ok(PricingResult::Updated)
    } else {
        Ok(PricingResult::Created)
    }
}

enum PricingResult {
    Created,
    Updated,
    Skipped,
}

fn parse_token_price_decimal(s: &str) -> Option<Decimal> {
    use std::str::FromStr;
    Decimal::from_str(s).ok()
}

async fn disable_all_models(db: &db::AppDatabase) -> Result<i64, AppError> {
    let result = sqlx::query(
        "UPDATE ai_model SET enabled = false, updated_at = $1 WHERE enabled = true",
    )
    .bind(Utc::now())
    .execute(db.writer())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?;

    Ok(result.rows_affected() as i64)
}

async fn deactivate_orphaned_models(db: &db::AppDatabase) -> Result<i64, AppError> {
    let now = Utc::now();
    sqlx::query(
        "UPDATE ai_model_version SET enabled = false, updated_at = $1 \
         WHERE model IN (SELECT id FROM ai_model WHERE enabled = false AND deleted_at IS NULL)",
    )
    .bind(now)
    .execute(db.writer())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?;

    let result = sqlx::query(
        "UPDATE ai_model SET deleted_at = $1, updated_at = $1 \
         WHERE enabled = false AND deleted_at IS NULL",
    )
    .bind(now)
    .execute(db.writer())
    .await
    .map_err(|e| AppError::DatabaseError(e.to_string()))?;

    Ok(result.rows_affected() as i64)
}

async fn sync_models_from_upstream(
    db: &db::AppDatabase,
    upstream_models: Vec<UpstreamModel>,
) -> SyncModelsResponse {
    let models_offline = disable_all_models(db).await.unwrap_or(0);

    tracing::info!(
        upstream_total = upstream_models.len(),
        "syncing models from upstream"
    );

    let mut models_created = 0i64;
    let mut models_updated = 0i64;
    let mut versions_created = 0i64;
    let mut pricing_created = 0i64;
    let mut pricing_updated = 0i64;

    for model in &upstream_models {
        let provider_slug = extract_provider_name(model);
        let provider = match upsert_provider(db, &provider_slug).await {
            Ok(p) => p,
            Err(e) => {
                tracing::warn!(
                    provider = %provider_slug,
                    error = %e,
                    "sync: upsert_provider error"
                );
                continue;
            }
        };

        let (model_record, _is_new) = match upsert_model(db, provider.id, model).await {
            Ok((m, created)) => {
                if created {
                    models_created += 1;
                } else {
                    models_updated += 1;
                }
                (m, created)
            }
            Err(e) => {
                tracing::warn!(
                    model = %model.id,
                    error = %e,
                    "sync: upsert_model error"
                );
                continue;
            }
        };

        let (version_record, version_is_new) =
            match upsert_version(db, model_record.id, &model.id).await {
                Ok(v) => v,
                Err(e) => {
                    tracing::warn!(
                        model = %model.id,
                        error = %e,
                        "sync: upsert_version error"
                    );
                    continue;
                }
            };
        if version_is_new {
            versions_created += 1;
        }

        match upsert_pricing(db, version_record.id, model.pricing.as_ref()).await {
            Ok(PricingResult::Created) => pricing_created += 1,
            Ok(PricingResult::Updated) => pricing_updated += 1,
            Ok(PricingResult::Skipped) => {}
            Err(e) => {
                tracing::warn!(
                    model = %model.id,
                    error = %e,
                    "sync: upsert_pricing error"
                );
            }
        }
    }

    let deactivated = deactivate_orphaned_models(db).await.unwrap_or(0);

    SyncModelsResponse {
        models_created,
        models_updated,
        models_offline,
        models_deactivated: deactivated,
        versions_created,
        pricing_created,
        pricing_updated,
    }
}

impl AppService {
    pub async fn sync_upstream_models(&self) -> Result<SyncModelsResponse, AppError> {
        let api_key = self
            .config
            .ai_api_key()
            .map_err(|e| AppError::InternalServerError(format!("AI API key not configured: {}", e)))?;

        let base_url = self.config.ai_basic_url().unwrap_or_default();

        let config = EndpointConfig::new(&base_url, &api_key)
            .map_err(|e| AppError::InternalServerError(e.to_string()))?;

        let upstream_models = ai::sync::list_models(&config)
            .await
            .map_err(|e| AppError::InternalServerError(e.to_string()))?;

        tracing::info!(
            model_count = upstream_models.len(),
            "sync_upstream_models: {} models from upstream",
            upstream_models.len()
        );

        let result = sync_models_from_upstream(&self.db, upstream_models).await;

        tracing::info!(
            models_created = result.models_created,
            models_updated = result.models_updated,
            versions_created = result.versions_created,
            pricing_created = result.pricing_created,
            pricing_updated = result.pricing_updated,
            "sync_upstream_models: complete"
        );

        Ok(result)
    }
}

pub fn spawn_model_sync_loop(service: AppService) -> tokio::task::JoinHandle<()> {
    let db = service.db.clone();
    let config = service.config.clone();

    tokio::spawn(async move {
        sync_once(&db, &config).await;

        let mut tick = interval(Duration::from_secs(60 * 10));
        loop {
            tick.tick().await;
            sync_once(&db, &config).await;
        }
    })
}

async fn sync_once(db: &db::AppDatabase, config: &config::AppConfig) {
    let api_key = match config.ai_api_key() {
        Ok(k) => k,
        Err(e) => {
            tracing::warn!(error = %e, "Model sync: AI API key not configured");
            return;
        }
    };

    let base_url = config.ai_basic_url().unwrap_or_default();

    let endpoint_config = match EndpointConfig::new(&base_url, &api_key) {
        Ok(c) => c,
        Err(e) => {
            tracing::warn!(error = %e, "Model sync: invalid endpoint config");
            return;
        }
    };

    let upstream_models = match ai::sync::list_models(&endpoint_config).await {
        Ok(models) => models,
        Err(e) => {
            tracing::warn!(error = %e, "Model sync: failed to list upstream models");
            return;
        }
    };

    tracing::info!(
        model_count = upstream_models.len(),
        "Model sync: {} models from upstream",
        upstream_models.len()
    );

    let result = sync_models_from_upstream(db, upstream_models).await;

    tracing::info!(
        models_created = result.models_created,
        models_updated = result.models_updated,
        versions_created = result.versions_created,
        pricing_created = result.pricing_created,
        pricing_updated = result.pricing_updated,
        "Model sync complete"
    );
}