import { dbGlobal } from "drizzle-pkg/lib/db";
import { llmProviders, llmModels } from "drizzle-pkg/lib/schema/llm";
import { eq, desc, like, and, sql } from "drizzle-orm";
import type { LlmParseMode, LlmProviderStatus, LlmModelType } from "drizzle-pkg/lib/schema/llm";

export interface LlmProviderRow {
  id: number;
  name: string;
  slug: string;
  baseUrl: string | null;
  parseMode: LlmParseMode;
  apiKey: string | null;
  status: LlmProviderStatus;
  description: string | null;
  createdAt: Date;
  updatedAt: Date;
}

export interface LlmModelRow {
  id: number;
  providerId: number;
  name: string;
  modelId: string;
  type: LlmModelType;
  enabled: number;
  description: string | null;
  maxTokens: number | null;
  createdAt: Date;
  updatedAt: Date;
}

export interface LlmProviderWithModels extends Omit<LlmProviderRow, "apiKey"> {
  apiKeySet: boolean;
  models: LlmModelRow[];
}

export async function listProviders(
  page = 1,
  pageSize = 20,
  search?: string,
  status?: LlmProviderStatus,
) {
  const conditions = [];
  if (search) {
    conditions.push(like(llmProviders.name, `%${search}%`));
  }
  if (status) {
    conditions.push(eq(llmProviders.status, status));
  }

  const where = conditions.length > 0 ? and(...conditions) : undefined;

  const [countResult] = await dbGlobal
    .select({ count: sql<number>`count(*)` })
    .from(llmProviders)
    .where(where);

  const total = countResult?.count ?? 0;
  const totalPages = Math.ceil(total / pageSize);

  const rows = await dbGlobal
    .select()
    .from(llmProviders)
    .where(where)
    .orderBy(desc(llmProviders.createdAt))
    .limit(pageSize)
    .offset((page - 1) * pageSize);

  const sanitized = rows.map(({ apiKey, ...rest }) => ({
    ...rest,
    apiKeySet: !!apiKey,
  }));

  return { list: sanitized, total, page, pageSize, totalPages };
}

export async function getProviderById(id: number) {
  const [row] = await dbGlobal
    .select()
    .from(llmProviders)
    .where(eq(llmProviders.id, id))
    .limit(1);
  return row ?? null;
}

export async function getProviderWithModels(id: number): Promise<LlmProviderWithModels | null> {
  const provider = await getProviderById(id);
  if (!provider) return null;

  const models = await dbGlobal
    .select()
    .from(llmModels)
    .where(eq(llmModels.providerId, id))
    .orderBy(desc(llmModels.createdAt));

  const { apiKey, ...rest } = provider;
  return {
    ...rest,
    apiKeySet: !!apiKey,
    models,
  };
}

export async function createProvider(data: {
  name: string;
  slug: string;
  baseUrl?: string;
  parseMode: LlmParseMode;
  apiKey?: string;
  status?: LlmProviderStatus;
  description?: string;
}) {
  const [inserted] = await dbGlobal
    .insert(llmProviders)
    .values({
      name: data.name,
      slug: data.slug,
      baseUrl: data.baseUrl || null,
      parseMode: data.parseMode,
      apiKey: data.apiKey || null,
      status: data.status || "active",
      description: data.description || null,
    })
    .returning({ id: llmProviders.id });
  return inserted!;
}

export async function updateProvider(
  id: number,
  data: {
    name?: string;
    slug?: string;
    baseUrl?: string;
    parseMode?: LlmParseMode;
    apiKey?: string;
    status?: LlmProviderStatus;
    description?: string;
  },
) {
  const updates: Record<string, any> = {};
  if (data.name !== undefined) updates.name = data.name;
  if (data.slug !== undefined) updates.slug = data.slug;
  if (data.baseUrl !== undefined) updates.baseUrl = data.baseUrl;
  if (data.parseMode !== undefined) updates.parseMode = data.parseMode;
  if (data.status !== undefined) updates.status = data.status;
  if (data.description !== undefined) updates.description = data.description;
  if (data.apiKey !== undefined) {
    if (data.apiKey === "") {
      updates.apiKey = null;
    } else if (data.apiKey !== "__unchanged__") {
      updates.apiKey = data.apiKey;
    }
  }

  if (Object.keys(updates).length === 0) return;

  await dbGlobal
    .update(llmProviders)
    .set(updates)
    .where(eq(llmProviders.id, id));
}

export async function deleteProvider(id: number) {
  await dbGlobal.delete(llmProviders).where(eq(llmProviders.id, id));
}

export async function listModelsByProvider(providerId: number) {
  return dbGlobal
    .select()
    .from(llmModels)
    .where(eq(llmModels.providerId, providerId))
    .orderBy(desc(llmModels.createdAt));
}

export async function createModel(data: {
  providerId: number;
  name: string;
  modelId: string;
  type: LlmModelType;
  enabled?: number;
  description?: string;
  maxTokens?: number;
}) {
  const [inserted] = await dbGlobal
    .insert(llmModels)
    .values({
      providerId: data.providerId,
      name: data.name,
      modelId: data.modelId,
      type: data.type,
      enabled: data.enabled ?? 1,
      description: data.description || null,
      maxTokens: data.maxTokens || null,
    })
    .returning({ id: llmModels.id });
  return inserted!;
}

export async function updateModel(
  id: number,
  data: {
    name?: string;
    modelId?: string;
    type?: LlmModelType;
    enabled?: number;
    description?: string;
    maxTokens?: number;
  },
) {
  const updates: Record<string, any> = {};
  if (data.name !== undefined) updates.name = data.name;
  if (data.modelId !== undefined) updates.modelId = data.modelId;
  if (data.type !== undefined) updates.type = data.type;
  if (data.enabled !== undefined) updates.enabled = data.enabled;
  if (data.description !== undefined) updates.description = data.description;
  if (data.maxTokens !== undefined) updates.maxTokens = data.maxTokens;

  if (Object.keys(updates).length === 0) return;

  await dbGlobal
    .update(llmModels)
    .set(updates)
    .where(eq(llmModels.id, id));
}

export async function deleteModel(id: number) {
  await dbGlobal.delete(llmModels).where(eq(llmModels.id, id));
}