initial commit

backend/Dockerfile

@@ -0,0 +1,8 @@
+FROM node:22-alpine
+
+WORKDIR /app
+COPY package.json ./
+RUN npm install
+COPY . .
+EXPOSE 3001
+CMD ["npm", "run", "start"]

backend/db/schema.sql

@@ -0,0 +1,122 @@
+CREATE TABLE IF NOT EXISTS environments (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS skills (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL,
+  subcategory text,
+  UNIQUE (name, subcategory)
+);
+
+CREATE TABLE IF NOT EXISTS favorite_things (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS pokemon (
+  id integer PRIMARY KEY,
+  name text NOT NULL UNIQUE,
+  environment_id integer NOT NULL REFERENCES environments(id)
+);
+
+CREATE TABLE IF NOT EXISTS pokemon_skills (
+  pokemon_id integer NOT NULL REFERENCES pokemon(id) ON DELETE CASCADE,
+  skill_id integer NOT NULL REFERENCES skills(id),
+  PRIMARY KEY (pokemon_id, skill_id)
+);
+
+CREATE TABLE IF NOT EXISTS pokemon_favorite_things (
+  pokemon_id integer NOT NULL REFERENCES pokemon(id) ON DELETE CASCADE,
+  favorite_thing_id integer NOT NULL REFERENCES favorite_things(id),
+  PRIMARY KEY (pokemon_id, favorite_thing_id)
+);
+
+CREATE TABLE IF NOT EXISTS item_categories (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS item_usages (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS acquisition_methods (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS item_tags (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS recipes (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS recipe_acquisition_methods (
+  recipe_id integer NOT NULL REFERENCES recipes(id) ON DELETE CASCADE,
+  acquisition_method_id integer NOT NULL REFERENCES acquisition_methods(id),
+  PRIMARY KEY (recipe_id, acquisition_method_id)
+);
+
+CREATE TABLE IF NOT EXISTS items (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE,
+  category_id integer NOT NULL REFERENCES item_categories(id),
+  usage_id integer NOT NULL REFERENCES item_usages(id),
+  recipe_id integer REFERENCES recipes(id),
+  dyeable boolean NOT NULL DEFAULT false,
+  dual_dyeable boolean NOT NULL DEFAULT false,
+  pattern_editable boolean NOT NULL DEFAULT false
+);
+
+CREATE TABLE IF NOT EXISTS item_acquisition_methods (
+  item_id integer NOT NULL REFERENCES items(id) ON DELETE CASCADE,
+  acquisition_method_id integer NOT NULL REFERENCES acquisition_methods(id),
+  PRIMARY KEY (item_id, acquisition_method_id)
+);
+
+CREATE TABLE IF NOT EXISTS item_item_tags (
+  item_id integer NOT NULL REFERENCES items(id) ON DELETE CASCADE,
+  item_tag_id integer NOT NULL REFERENCES item_tags(id),
+  PRIMARY KEY (item_id, item_tag_id)
+);
+
+CREATE TABLE IF NOT EXISTS recipe_materials (
+  recipe_id integer NOT NULL REFERENCES recipes(id) ON DELETE CASCADE,
+  item_id integer NOT NULL REFERENCES items(id),
+  quantity integer NOT NULL CHECK (quantity > 0),
+  PRIMARY KEY (recipe_id, item_id)
+);
+
+CREATE TABLE IF NOT EXISTS maps (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS habitats (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  name text NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS habitat_recipe_items (
+  habitat_id integer NOT NULL REFERENCES habitats(id) ON DELETE CASCADE,
+  item_id integer NOT NULL REFERENCES items(id),
+  quantity integer NOT NULL CHECK (quantity > 0),
+  PRIMARY KEY (habitat_id, item_id)
+);
+
+CREATE TABLE IF NOT EXISTS habitat_pokemon (
+  habitat_id integer NOT NULL REFERENCES habitats(id) ON DELETE CASCADE,
+  pokemon_id integer NOT NULL REFERENCES pokemon(id) ON DELETE CASCADE,
+  map_id integer NOT NULL REFERENCES maps(id),
+  time_of_day text NOT NULL CHECK (time_of_day IN ('早晨', '中午', '傍晚', '晚上')),
+  weather text NOT NULL CHECK (weather IN ('晴天', '阴天', '雨天')),
+  rarity integer NOT NULL CHECK (rarity BETWEEN 1 AND 3),
+  PRIMARY KEY (habitat_id, pokemon_id, map_id, time_of_day, weather)
+);

backend/db/seed.sql

@@ -0,0 +1,147 @@
+INSERT INTO environments (id, name) VALUES
+  (1, '森林'),
+  (2, '水边'),
+  (3, '草原')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO skills (id, name, subcategory) VALUES
+  (1, '采集', NULL),
+  (2, '乱撒', '棉花'),
+  (3, '浇水', NULL),
+  (4, '搬运', NULL)
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO favorite_things (id, name) VALUES
+  (1, '莓果'),
+  (2, '花朵'),
+  (3, '木材'),
+  (4, '清水'),
+  (5, '棉花')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO pokemon (id, name, environment_id) VALUES
+  (1, '妙蛙种子', 1),
+  (4, '小火龙', 3),
+  (7, '杰尼龟', 2),
+  (25, '皮卡丘', 3)
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO pokemon_skills (pokemon_id, skill_id) VALUES
+  (1, 1),
+  (1, 3),
+  (4, 4),
+  (7, 3),
+  (25, 1),
+  (25, 2)
+ON CONFLICT DO NOTHING;
+
+INSERT INTO pokemon_favorite_things (pokemon_id, favorite_thing_id) VALUES
+  (1, 1),
+  (1, 2),
+  (4, 3),
+  (7, 4),
+  (25, 1),
+  (25, 5)
+ON CONFLICT DO NOTHING;
+
+INSERT INTO item_categories (id, name) VALUES
+  (1, '家具'),
+  (2, '材料'),
+  (3, '装饰')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO item_usages (id, name) VALUES
+  (1, '栖息地配方'),
+  (2, '建造'),
+  (3, '装饰')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO acquisition_methods (id, name) VALUES
+  (1, '采集'),
+  (2, '制作'),
+  (3, '探索')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO item_tags (id, name) VALUES
+  (1, '自然'),
+  (2, '木质'),
+  (3, '柔软'),
+  (4, '水域')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO recipes (id, name) VALUES
+  (1, '木质长椅材料单'),
+  (2, '棉花垫材料单')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO items (id, name, category_id, usage_id, recipe_id, dyeable, dual_dyeable, pattern_editable) VALUES
+  (1, '原木', 2, 2, NULL, false, false, false),
+  (2, '棉花', 2, 2, NULL, true, false, false),
+  (3, '木质长椅', 1, 3, 1, true, true, false),
+  (4, '清水瓶', 3, 1, NULL, false, false, true),
+  (5, '棉花垫', 1, 3, 2, true, false, true)
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO item_acquisition_methods (item_id, acquisition_method_id) VALUES
+  (1, 1),
+  (2, 1),
+  (3, 2),
+  (4, 3),
+  (5, 2)
+ON CONFLICT DO NOTHING;
+
+INSERT INTO item_item_tags (item_id, item_tag_id) VALUES
+  (1, 1),
+  (1, 2),
+  (2, 3),
+  (3, 2),
+  (4, 4),
+  (5, 3)
+ON CONFLICT DO NOTHING;
+
+INSERT INTO recipe_acquisition_methods (recipe_id, acquisition_method_id) VALUES
+  (1, 2),
+  (2, 2)
+ON CONFLICT DO NOTHING;
+
+INSERT INTO recipe_materials (recipe_id, item_id, quantity) VALUES
+  (1, 1, 6),
+  (2, 2, 4)
+ON CONFLICT DO NOTHING;
+
+INSERT INTO maps (id, name) VALUES
+  (1, '起始平原'),
+  (2, '微风森林'),
+  (3, '湖畔小径')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO habitats (id, name) VALUES
+  (1, '绿荫营地'),
+  (2, '湖边小窝')
+ON CONFLICT (id) DO NOTHING;
+
+INSERT INTO habitat_recipe_items (habitat_id, item_id, quantity) VALUES
+  (1, 1, 8),
+  (1, 3, 1),
+  (2, 2, 3),
+  (2, 4, 2)
+ON CONFLICT DO NOTHING;
+
+INSERT INTO habitat_pokemon (habitat_id, pokemon_id, map_id, time_of_day, weather, rarity) VALUES
+  (1, 1, 2, '早晨', '晴天', 1),
+  (1, 25, 1, '傍晚', '阴天', 2),
+  (2, 7, 3, '中午', '雨天', 1),
+  (2, 1, 3, '早晨', '雨天', 2)
+ON CONFLICT DO NOTHING;
+
+SELECT setval(pg_get_serial_sequence('environments', 'id'), (SELECT max(id) FROM environments));
+SELECT setval(pg_get_serial_sequence('skills', 'id'), (SELECT max(id) FROM skills));
+SELECT setval(pg_get_serial_sequence('favorite_things', 'id'), (SELECT max(id) FROM favorite_things));
+SELECT setval(pg_get_serial_sequence('item_categories', 'id'), (SELECT max(id) FROM item_categories));
+SELECT setval(pg_get_serial_sequence('item_usages', 'id'), (SELECT max(id) FROM item_usages));
+SELECT setval(pg_get_serial_sequence('acquisition_methods', 'id'), (SELECT max(id) FROM acquisition_methods));
+SELECT setval(pg_get_serial_sequence('item_tags', 'id'), (SELECT max(id) FROM item_tags));
+SELECT setval(pg_get_serial_sequence('recipes', 'id'), (SELECT max(id) FROM recipes));
+SELECT setval(pg_get_serial_sequence('items', 'id'), (SELECT max(id) FROM items));
+SELECT setval(pg_get_serial_sequence('maps', 'id'), (SELECT max(id) FROM maps));
+SELECT setval(pg_get_serial_sequence('habitats', 'id'), (SELECT max(id) FROM habitats));

backend/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "@pokopia/backend",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "tsx watch src/server.ts",
+    "start": "tsx src/server.ts",
+    "build": "tsc --noEmit",
+    "lint": "tsc --noEmit",
+    "typecheck": "tsc --noEmit",
+    "test": "node --test --import tsx tests/*.test.ts"
+  },
+  "dependencies": {
+    "@fastify/cors": "latest",
+    "fastify": "latest",
+    "pg": "latest"
+  },
+  "devDependencies": {
+    "@types/node": "latest",
+    "@types/pg": "latest",
+    "tsx": "latest",
+    "typescript": "latest"
+  }
+}

backend/src/db.ts

@@ -0,0 +1,31 @@
+import { readFile } from 'node:fs/promises';
+import path from 'node:path';
+import pg from 'pg';
+
+const { Pool } = pg;
+type QueryResultRow = pg.QueryResultRow;
+
+const databaseUrl = process.env.DATABASE_URL ?? 'postgres://pokopia:pokopia@localhost:5432/pokopia';
+
+export const pool = new Pool({
+  connectionString: databaseUrl
+});
+
+export async function query<T extends QueryResultRow>(sql: string, params: unknown[] = []): Promise<T[]> {
+  const result = await pool.query<T>(sql, params);
+  return result.rows;
+}
+
+export async function queryOne<T extends QueryResultRow>(sql: string, params: unknown[] = []): Promise<T | null> {
+  const rows = await query<T>(sql, params);
+  return rows[0] ?? null;
+}
+
+export async function initializeDatabase(): Promise<void> {
+  const dbDir = path.join(process.cwd(), 'db');
+  const schema = await readFile(path.join(dbDir, 'schema.sql'), 'utf8');
+  const seed = await readFile(path.join(dbDir, 'seed.sql'), 'utf8');
+
+  await pool.query(schema);
+  await pool.query(seed);
+}

backend/src/filter.ts

@@ -0,0 +1,49 @@
+export type MatchMode = 'any' | 'all';
+
+export function parseIdList(value: unknown): number[] {
+  if (typeof value !== 'string' || value.trim() === '') {
+    return [];
+  }
+
+  return value
+    .split(',')
+    .map((item) => Number(item.trim()))
+    .filter((item) => Number.isInteger(item) && item > 0);
+}
+
+export function parseMatchMode(value: unknown): MatchMode {
+  return value === 'all' ? 'all' : 'any';
+}
+
+export function sqlForRelationFilter(
+  ids: number[],
+  mode: MatchMode,
+  relationTable: string,
+  ownerColumn: string,
+  targetColumn: string,
+  ownerExpression: string,
+  params: unknown[]
+): string {
+  if (ids.length === 0) {
+    return '';
+  }
+
+  params.push(ids);
+  const paramIndex = params.length;
+
+  if (mode === 'all') {
+    return `(
+      SELECT count(DISTINCT ${targetColumn})
+      FROM ${relationTable}
+      WHERE ${ownerColumn} = ${ownerExpression}
+        AND ${targetColumn} = ANY($${paramIndex}::int[])
+    ) = ${ids.length}`;
+  }
+
+  return `EXISTS (
+    SELECT 1
+    FROM ${relationTable}
+    WHERE ${ownerColumn} = ${ownerExpression}
+      AND ${targetColumn} = ANY($${paramIndex}::int[])
+  )`;
+}

backend/src/queries.ts

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+import { parseIdList, parseMatchMode, sqlForRelationFilter } from './filter.ts';
+import { query, queryOne } from './db.ts';
+
+type QueryValue = string | string[] | undefined;
+
+type QueryParams = Record<string, QueryValue>;
+
+function asString(value: QueryValue): string | undefined {
+  return Array.isArray(value) ? value[0] : value;
+}
+
+function optionSelect(tableName: string): Promise<Array<{ id: number; name: string }>> {
+  return query(`SELECT id, name FROM ${tableName} ORDER BY name`);
+}
+
+const pokemonProjection = `
+  SELECT
+    p.id,
+    p.name,
+    json_build_object('id', e.id, 'name', e.name) AS environment,
+    COALESCE((
+      SELECT json_agg(json_build_object('id', s.id, 'name', s.name, 'subcategory', s.subcategory) ORDER BY s.name, s.subcategory)
+      FROM pokemon_skills ps
+      JOIN skills s ON s.id = ps.skill_id
+      WHERE ps.pokemon_id = p.id
+    ), '[]'::json) AS skills,
+    COALESCE((
+      SELECT json_agg(json_build_object('id', ft.id, 'name', ft.name) ORDER BY ft.name)
+      FROM pokemon_favorite_things pft
+      JOIN favorite_things ft ON ft.id = pft.favorite_thing_id
+      WHERE pft.pokemon_id = p.id
+    ), '[]'::json) AS favorite_things
+  FROM pokemon p
+  JOIN environments e ON e.id = p.environment_id
+`;
+
+export async function getOptions() {
+  const [skills, environments, favoriteThings, itemCategories, itemUsages, itemTags] = await Promise.all([
+    query<{ id: number; name: string; subcategory: string | null }>(
+      'SELECT id, name, subcategory FROM skills ORDER BY name, subcategory'
+    ),
+    optionSelect('environments'),
+    optionSelect('favorite_things'),
+    optionSelect('item_categories'),
+    optionSelect('item_usages'),
+    optionSelect('item_tags')
+  ]);
+
+  return {
+    skills,
+    environments,
+    favoriteThings,
+    itemCategories,
+    itemUsages,
+    itemTags
+  };
+}
+
+export async function listPokemon(paramsQuery: QueryParams) {
+  const params: unknown[] = [];
+  const conditions: string[] = [];
+  const search = asString(paramsQuery.search)?.trim();
+  const environmentId = Number(asString(paramsQuery.environmentId));
+  const skillIds = parseIdList(asString(paramsQuery.skillIds));
+  const favoriteThingIds = parseIdList(asString(paramsQuery.favoriteThingIds));
+
+  if (search) {
+    params.push(`%${search}%`);
+    conditions.push(`p.name ILIKE $${params.length}`);
+  }
+
+  if (Number.isInteger(environmentId) && environmentId > 0) {
+    params.push(environmentId);
+    conditions.push(`p.environment_id = $${params.length}`);
+  }
+
+  const skillFilter = sqlForRelationFilter(
+    skillIds,
+    parseMatchMode(asString(paramsQuery.skillMode)),
+    'pokemon_skills',
+    'pokemon_id',
+    'skill_id',
+    'p.id',
+    params
+  );
+  if (skillFilter) {
+    conditions.push(skillFilter);
+  }
+
+  const favoriteThingFilter = sqlForRelationFilter(
+    favoriteThingIds,
+    parseMatchMode(asString(paramsQuery.favoriteThingMode)),
+    'pokemon_favorite_things',
+    'pokemon_id',
+    'favorite_thing_id',
+    'p.id',
+    params
+  );
+  if (favoriteThingFilter) {
+    conditions.push(favoriteThingFilter);
+  }
+
+  const whereClause = conditions.length > 0 ? `WHERE ${conditions.join(' AND ')}` : '';
+  return query(`${pokemonProjection} ${whereClause} ORDER BY p.id`, params);
+}
+
+export async function getPokemon(id: number) {
+  const pokemon = await queryOne(`${pokemonProjection} WHERE p.id = $1`, [id]);
+  if (!pokemon) {
+    return null;
+  }
+
+  const habitats = await query(
+    `
+      SELECT
+        h.id,
+        h.name,
+        hp.time_of_day,
+        hp.weather,
+        hp.rarity,
+        json_build_object('id', m.id, 'name', m.name) AS map
+      FROM habitat_pokemon hp
+      JOIN habitats h ON h.id = hp.habitat_id
+      JOIN maps m ON m.id = hp.map_id
+      WHERE hp.pokemon_id = $1
+      ORDER BY h.name, hp.rarity, m.name
+    `,
+    [id]
+  );
+
+  return { ...pokemon, habitats };
+}
+
+export async function listHabitats() {
+  return query(`
+    SELECT
+      h.id,
+      h.name,
+      COALESCE((
+        SELECT json_agg(json_build_object('id', i.id, 'name', i.name, 'quantity', hri.quantity) ORDER BY i.name)
+        FROM habitat_recipe_items hri
+        JOIN items i ON i.id = hri.item_id
+        WHERE hri.habitat_id = h.id
+      ), '[]'::json) AS recipe,
+      COALESCE((
+        SELECT json_agg(DISTINCT jsonb_build_object('id', p.id, 'name', p.name))
+        FROM habitat_pokemon hp
+        JOIN pokemon p ON p.id = hp.pokemon_id
+        WHERE hp.habitat_id = h.id
+      ), '[]'::json) AS pokemon
+    FROM habitats h
+    ORDER BY h.name
+  `);
+}
+
+export async function getHabitat(id: number) {
+  const habitat = await queryOne(
+    `
+      SELECT
+        h.id,
+        h.name,
+        COALESCE((
+          SELECT json_agg(json_build_object('id', i.id, 'name', i.name, 'quantity', hri.quantity) ORDER BY i.name)
+          FROM habitat_recipe_items hri
+          JOIN items i ON i.id = hri.item_id
+          WHERE hri.habitat_id = h.id
+        ), '[]'::json) AS recipe
+      FROM habitats h
+      WHERE h.id = $1
+    `,
+    [id]
+  );
+
+  if (!habitat) {
+    return null;
+  }
+
+  const pokemon = await query(
+    `
+      SELECT
+        p.id,
+        p.name,
+        hp.time_of_day,
+        hp.weather,
+        hp.rarity,
+        json_build_object('id', m.id, 'name', m.name) AS map
+      FROM habitat_pokemon hp
+      JOIN pokemon p ON p.id = hp.pokemon_id
+      JOIN maps m ON m.id = hp.map_id
+      WHERE hp.habitat_id = $1
+      ORDER BY hp.rarity, p.id, m.name
+    `,
+    [id]
+  );
+
+  return { ...habitat, pokemon };
+}
+
+const itemProjection = `
+  SELECT
+    i.id,
+    i.name,
+    json_build_object('id', c.id, 'name', c.name) AS category,
+    json_build_object('id', u.id, 'name', u.name) AS usage,
+    json_build_object(
+      'dyeable', i.dyeable,
+      'dualDyeable', i.dual_dyeable,
+      'patternEditable', i.pattern_editable
+    ) AS customization,
+    COALESCE((
+      SELECT json_agg(json_build_object('id', t.id, 'name', t.name) ORDER BY t.name)
+      FROM item_item_tags iit
+      JOIN item_tags t ON t.id = iit.item_tag_id
+      WHERE iit.item_id = i.id
+    ), '[]'::json) AS tags
+  FROM items i
+  JOIN item_categories c ON c.id = i.category_id
+  JOIN item_usages u ON u.id = i.usage_id
+`;
+
+export async function listItems(paramsQuery: QueryParams) {
+  const params: unknown[] = [];
+  const conditions: string[] = [];
+  const categoryId = Number(asString(paramsQuery.categoryId));
+  const usageId = Number(asString(paramsQuery.usageId));
+  const tagIds = parseIdList(asString(paramsQuery.tagIds));
+  const search = asString(paramsQuery.search)?.trim();
+
+  if (search) {
+    params.push(`%${search}%`);
+    conditions.push(`i.name ILIKE $${params.length}`);
+  }
+
+  if (Number.isInteger(categoryId) && categoryId > 0) {
+    params.push(categoryId);
+    conditions.push(`i.category_id = $${params.length}`);
+  }
+
+  if (Number.isInteger(usageId) && usageId > 0) {
+    params.push(usageId);
+    conditions.push(`i.usage_id = $${params.length}`);
+  }
+
+  const tagFilter = sqlForRelationFilter(
+    tagIds,
+    'any',
+    'item_item_tags',
+    'item_id',
+    'item_tag_id',
+    'i.id',
+    params
+  );
+  if (tagFilter) {
+    conditions.push(tagFilter);
+  }
+
+  const whereClause = conditions.length > 0 ? `WHERE ${conditions.join(' AND ')}` : '';
+  return query(`${itemProjection} ${whereClause} ORDER BY c.name, i.name`, params);
+}
+
+export async function getItem(id: number) {
+  const item = await queryOne(`${itemProjection} WHERE i.id = $1`, [id]);
+  if (!item) {
+    return null;
+  }
+
+  const [acquisitionMethods, recipe, relatedHabitats] = await Promise.all([
+    query(
+      `
+        SELECT am.id, am.name
+        FROM item_acquisition_methods iam
+        JOIN acquisition_methods am ON am.id = iam.acquisition_method_id
+        WHERE iam.item_id = $1
+        ORDER BY am.name
+      `,
+      [id]
+    ),
+    queryOne(
+      `
+        SELECT
+          r.id,
+          r.name,
+          COALESCE((
+            SELECT json_agg(json_build_object('id', am.id, 'name', am.name) ORDER BY am.name)
+            FROM recipe_acquisition_methods ram
+            JOIN acquisition_methods am ON am.id = ram.acquisition_method_id
+            WHERE ram.recipe_id = r.id
+          ), '[]'::json) AS acquisition_methods,
+          COALESCE((
+            SELECT json_agg(json_build_object('id', mi.id, 'name', mi.name, 'quantity', rm.quantity) ORDER BY mi.name)
+            FROM recipe_materials rm
+            JOIN items mi ON mi.id = rm.item_id
+            WHERE rm.recipe_id = r.id
+          ), '[]'::json) AS materials
+        FROM items i
+        JOIN recipes r ON r.id = i.recipe_id
+        WHERE i.id = $1
+      `,
+      [id]
+    ),
+    query(
+      `
+        SELECT h.id, h.name, hri.quantity
+        FROM habitat_recipe_items hri
+        JOIN habitats h ON h.id = hri.habitat_id
+        WHERE hri.item_id = $1
+        ORDER BY h.name
+      `,
+      [id]
+    )
+  ]);
+
+  return { ...item, acquisitionMethods, recipe, relatedHabitats };
+}
+
+export async function listRecipes() {
+  return query(`
+    SELECT
+      r.id,
+      r.name,
+      COALESCE((
+        SELECT json_agg(json_build_object('id', i.id, 'name', i.name, 'quantity', rm.quantity) ORDER BY i.name)
+        FROM recipe_materials rm
+        JOIN items i ON i.id = rm.item_id
+        WHERE rm.recipe_id = r.id
+      ), '[]'::json) AS materials
+    FROM recipes r
+    ORDER BY r.name
+  `);
+}
+
+export async function getRecipe(id: number) {
+  return queryOne(
+    `
+      SELECT
+        r.id,
+        r.name,
+        COALESCE((
+          SELECT json_agg(json_build_object('id', am.id, 'name', am.name) ORDER BY am.name)
+          FROM recipe_acquisition_methods ram
+          JOIN acquisition_methods am ON am.id = ram.acquisition_method_id
+          WHERE ram.recipe_id = r.id
+        ), '[]'::json) AS acquisition_methods,
+        COALESCE((
+          SELECT json_agg(json_build_object('id', i.id, 'name', i.name, 'quantity', rm.quantity) ORDER BY i.name)
+          FROM recipe_materials rm
+          JOIN items i ON i.id = rm.item_id
+          WHERE rm.recipe_id = r.id
+        ), '[]'::json) AS materials
+      FROM recipes r
+      WHERE r.id = $1
+    `,
+    [id]
+  );
+}

backend/src/server.ts

@@ -0,0 +1,89 @@
+import cors from '@fastify/cors';
+import Fastify from 'fastify';
+import { initializeDatabase, pool } from './db.ts';
+import {
+  getHabitat,
+  getItem,
+  getOptions,
+  getPokemon,
+  getRecipe,
+  listHabitats,
+  listItems,
+  listPokemon,
+  listRecipes
+} from './queries.ts';
+
+const app = Fastify({
+  logger: true
+});
+
+await app.register(cors, {
+  origin: process.env.FRONTEND_ORIGIN ?? true
+});
+
+app.get('/health', async () => ({ ok: true }));
+
+app.get('/api/options', async () => getOptions());
+
+app.get('/api/pokemon', async (request) => listPokemon(request.query as Record<string, string | string[] | undefined>));
+
+app.get('/api/pokemon/:id', async (request, reply) => {
+  const { id } = request.params as { id: string };
+  const pokemon = await getPokemon(Number(id));
+
+  if (!pokemon) {
+    return reply.code(404).send({ message: 'Not found' });
+  }
+
+  return pokemon;
+});
+
+app.get('/api/habitats', async () => listHabitats());
+
+app.get('/api/habitats/:id', async (request, reply) => {
+  const { id } = request.params as { id: string };
+  const habitat = await getHabitat(Number(id));
+
+  if (!habitat) {
+    return reply.code(404).send({ message: 'Not found' });
+  }
+
+  return habitat;
+});
+
+app.get('/api/items', async (request) => listItems(request.query as Record<string, string | string[] | undefined>));
+
+app.get('/api/items/:id', async (request, reply) => {
+  const { id } = request.params as { id: string };
+  const item = await getItem(Number(id));
+
+  if (!item) {
+    return reply.code(404).send({ message: 'Not found' });
+  }
+
+  return item;
+});
+
+app.get('/api/recipes', async () => listRecipes());
+
+app.get('/api/recipes/:id', async (request, reply) => {
+  const { id } = request.params as { id: string };
+  const recipe = await getRecipe(Number(id));
+
+  if (!recipe) {
+    return reply.code(404).send({ message: 'Not found' });
+  }
+
+  return recipe;
+});
+
+const port = Number(process.env.BACKEND_PORT ?? 3001);
+
+try {
+  await initializeDatabase();
+  await app.listen({ host: '0.0.0.0', port });
+} catch (error) {
+  app.log.error(error);
+  await pool.end();
+  process.exit(1);
+}

backend/tests/filter.test.ts

@@ -0,0 +1,33 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
+import { parseIdList, parseMatchMode, sqlForRelationFilter } from '../src/filter.ts';
+
+describe('filter helpers', () => {
+  it('parses comma separated ids and drops invalid values', () => {
+    assert.deepEqual(parseIdList('1, 2, x, -1, 3'), [1, 2, 3]);
+  });
+
+  it('defaults match mode to any', () => {
+    assert.equal(parseMatchMode('all'), 'all');
+    assert.equal(parseMatchMode('anything'), 'any');
+    assert.equal(parseMatchMode(undefined), 'any');
+  });
+
+  it('builds relation filters with bound array parameters', () => {
+    const params: unknown[] = [];
+    const sql = sqlForRelationFilter(
+      [1, 2],
+      'all',
+      'pokemon_skills',
+      'pokemon_id',
+      'skill_id',
+      'p.id',
+      params
+    );
+
+    assert.equal(params.length, 1);
+    assert.deepEqual(params[0], [1, 2]);
+    assert.match(sql, /count\(DISTINCT skill_id\)/);
+    assert.match(sql, /= 2/);
+  });
+});

backend/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "allowImportingTsExtensions": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "types": ["node"]
+  },
+  "include": ["src/**/*.ts", "tests/**/*.ts"]
+}