import type Database from "bun:sqlite";

import { and, desc, eq } from "drizzle-orm";

import type { CreateEntityRequest, Entity, EntityType, UpdateEntityRequest } from "../../shared/api";
import type { Logger } from "../logger";

import { notDeleted, paginateQuery, softDeleteRecord, timestamp, wrap } from "./connection";
import { entities, projects } from "./schema";

export function createEntity(
  raw: Database,
  projectId: string,
  request: CreateEntityRequest,
  _logger: Logger,
): { entity: Entity } | { error: string; status: number } {
  const db = wrap(raw);
  const project = db
    .select()
    .from(projects)
    .where(and(eq(projects.id, projectId), notDeleted(projects)))
    .get();
  if (!project) return { error: "项目不存在", status: 404 };
  if (project.status === "archived") return { error: "已归档项目不可操作", status: 409 };

  const name = request.name.trim();
  if (!name) return { error: "实体名称不能为空", status: 400 };

  const duplicate = db
    .select({ id: entities.id })
    .from(entities)
    .where(and(eq(entities.projectId, projectId), eq(entities.name, name), notDeleted(entities)))
    .get();
  if (duplicate) return { error: "实体名称已存在", status: 409 };

  const id = crypto.randomUUID();
  const now = timestamp();

  db.insert(entities)
    .values({
      aliases: JSON.stringify(request.aliases ?? []),
      createdAt: now,
      description: request.description?.trim() ?? "",
      id,
      name,
      projectId,
      type: request.type,
      updatedAt: now,
    })
    .run();

  const row = db.select().from(entities).where(eq(entities.id, id)).get();
  return { entity: toEntity(row!) };
}

export function deleteEntity(
  raw: Database,
  projectId: string,
  entityId: string,
  _logger: Logger,
): { error: string; status: number } | { success: true } {
  const db = wrap(raw);
  const row = db
    .select()
    .from(entities)
    .where(and(eq(entities.id, entityId), notDeleted(entities)))
    .get();
  if (!row) return { error: "实体不存在", status: 404 };
  if (row.projectId !== projectId) return { error: "实体不属于该项目", status: 403 };

  softDeleteRecord(db, entities, entityId);
  return { success: true };
}

export function getEntity(
  raw: Database,
  projectId: string,
  entityId: string,
): { entity: Entity } | { error: string; status: number } {
  const db = wrap(raw);
  const row = db
    .select()
    .from(entities)
    .where(and(eq(entities.id, entityId), notDeleted(entities)))
    .get();
  if (!row) return { error: "实体不存在", status: 404 };
  if (row.projectId !== projectId) return { error: "实体不属于该项目", status: 403 };

  return { entity: toEntity(row) };
}

export function listEntities(
  raw: Database,
  projectId: string,
  options: { page: number; pageSize: number; type?: EntityType },
): { items: Entity[]; page: number; pageSize: number; total: number } {
  const conditions = [eq(entities.projectId, projectId)];

  if (options.type) {
    conditions.push(eq(entities.type, options.type));
  }

  return paginateQuery(raw, entities, {
    conditions,
    mapRow: toEntity,
    orderBy: () => desc(entities.createdAt),
    page: options.page,
    pageSize: options.pageSize,
    softDelete: entities.deletedAt,
  });
}

export function listEntityNames(
  raw: Database,
  projectId: string,
): Array<{ aliases: string[]; id: string; name: string }> {
  const db = wrap(raw);
  const rows = db
    .select({ aliases: entities.aliases, id: entities.id, name: entities.name })
    .from(entities)
    .where(and(eq(entities.projectId, projectId), notDeleted(entities)))
    .all();

  return rows.map((row) => ({
    aliases: JSON.parse(row.aliases) as string[],
    id: row.id,
    name: row.name,
  }));
}

export function updateEntity(
  raw: Database,
  projectId: string,
  entityId: string,
  request: UpdateEntityRequest,
  _logger: Logger,
): { entity: Entity } | { error: string; status: number } {
  const db = wrap(raw);
  const existing = db
    .select()
    .from(entities)
    .where(and(eq(entities.id, entityId), notDeleted(entities)))
    .get();
  if (!existing) return { error: "实体不存在", status: 404 };
  if (existing.projectId !== projectId) return { error: "实体不属于该项目", status: 403 };

  const updates: Partial<typeof entities.$inferInsert> = {
    updatedAt: timestamp(),
  };

  const name = request.name?.trim();
  if (name === "") return { error: "实体名称不能为空", status: 400 };
  if (name !== undefined && name !== existing.name) {
    const duplicate = db
      .select({ id: entities.id })
      .from(entities)
      .where(and(eq(entities.projectId, projectId), eq(entities.name, name), notDeleted(entities)))
      .get();
    if (duplicate) return { error: "实体名称已存在", status: 409 };
    updates.name = name;
  }

  if (request.type !== undefined) {
    updates.type = request.type;
  }

  if (request.description !== undefined) {
    updates.description = request.description.trim();
  }

  if (request.aliases !== undefined) {
    updates.aliases = JSON.stringify(request.aliases);
  }

  if (Object.keys(updates).length === 1 && updates.updatedAt) {
    return { entity: toEntity(existing) };
  }

  db.update(entities).set(updates).where(eq(entities.id, entityId)).run();

  const updated = db.select().from(entities).where(eq(entities.id, entityId)).get();
  return { entity: toEntity(updated!) };
}

function toEntity(row: typeof entities.$inferSelect): Entity {
  return {
    aliases: JSON.parse(row.aliases) as string[],
    createdAt: row.createdAt,
    description: row.description,
    id: row.id,
    name: row.name,
    projectId: row.projectId,
    type: row.type as EntityType,
    updatedAt: row.updatedAt,
  };
}