🎉 initial commit

devices-api/app-standalone.lua

@@ -0,0 +1,724 @@
+#!/usr/bin/env lua
+
+local socket = require("socket")
+local cjson = require("cjson")
+local db = require("db")
+local log = require("log")
+
+-- Optional dependencies
+local redis
+pcall(function() redis = require("redis") end)
+
+local digest
+pcall(function() digest = require("openssl.digest") end)
+
+local app = {}
+app.port = tonumber(os.getenv("API_PORT")) or 8080
+app.host = "0.0.0.0"
+
+-- Database configuration (from db.lua)
+local DB_HOST = os.getenv("DB_HOST") or "localhost"
+local DB_PORT = tonumber(os.getenv("DB_PORT")) or 5432
+local DB_NAME = os.getenv("DB_NAME") or "handheld_devices"
+
+-- Redis configuration
+local REDIS_HOST = os.getenv("REDIS_HOST") or "127.0.0.1"
+local REDIS_PORT = tonumber(os.getenv("REDIS_PORT")) or 6379
+
+-- Redis client with retry
+local function get_redis_connection()
+    if not redis then return nil end
+    local attempts = 3
+    for i = 1, attempts do
+        local ok, red = pcall(redis.connect, REDIS_HOST, REDIS_PORT)
+        if ok and red then return red end
+        if i < attempts then
+            socket.sleep(math.min(2 ^ i * 0.1, 2))
+        end
+    end
+    return nil
+end
+
+-- Redis ping for health
+local function redis_ping()
+    local red = get_redis_connection()
+    if not red then return false end
+    local ok, res = pcall(red.ping, red)
+    if ok and res == "PONG" then return true end
+    return false
+end
+
+-- Ensure tables exist
+local function init_db()
+    local ok, err = db.with_retry(function()
+        return db.with_connection(function(conn)
+            conn:query([[
+    CREATE TABLE IF NOT EXISTS devices (
+      id SERIAL PRIMARY KEY,
+      name VARCHAR(255) NOT NULL,
+      manufacturer VARCHAR(255) NOT NULL,
+      release_year INTEGER,
+      cpu VARCHAR(255),
+      ram_mb INTEGER,
+      storage_mb INTEGER,
+      display_size VARCHAR(50),
+      battery_hours REAL,
+      created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+      updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    );
+
+    CREATE TABLE IF NOT EXISTS ratings (
+      id SERIAL PRIMARY KEY,
+      device_id INTEGER NOT NULL REFERENCES devices(id) ON DELETE CASCADE,
+      user_id VARCHAR(255) NOT NULL,
+      score INTEGER CHECK (score >= 1 AND score <= 5),
+      created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    );
+
+    CREATE TABLE IF NOT EXISTS reviews (
+      id SERIAL PRIMARY KEY,
+      device_id INTEGER NOT NULL REFERENCES devices(id) ON DELETE CASCADE,
+      user_id VARCHAR(255) NOT NULL,
+      content TEXT NOT NULL,
+      created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    );
+  ]])
+            return true
+        end)
+    end)
+    if not ok then
+        error("Failed to init DB: " .. tostring(err))
+    end
+end
+
+-- Seed initial data
+local function seed_db()
+    db.with_connection(function(conn)
+        local res, err = conn:query("SELECT COUNT(*) as total FROM devices")
+        local count = 0
+        if res and res[1] then
+            count = tonumber(res[1].total) or 0
+        end
+
+        if count == 0 then
+            log.info("Seeding initial devices", { component = "seed" })
+            local devices = {
+            {
+                name = "Steam Deck",
+                manufacturer = "Valve",
+                release_year = 2022,
+                cpu = "AMD Zen 2",
+                ram_mb = 16384,
+                storage_mb = 524288,
+                display_size = "7-inch",
+                battery_hours = 4.0
+            },
+            {
+                name = "Nintendo Switch",
+                manufacturer = "Nintendo",
+                release_year = 2017,
+                cpu = "Nvidia Tegra X1",
+                ram_mb = 4096,
+                storage_mb = 32768,
+                display_size = "6.2-inch",
+                battery_hours = 5.5
+            },
+            {
+                name = "ROG Ally",
+                manufacturer = "ASUS",
+                release_year = 2023,
+                cpu = "AMD Ryzen Z1 Extreme",
+                ram_mb = 16384,
+                storage_mb = 524288,
+                display_size = "7-inch",
+                battery_hours = 3.5
+            }
+        }
+
+        for _, device in ipairs(devices) do
+            conn:query(
+                "INSERT INTO devices (name, manufacturer, release_year, cpu, ram_mb, storage_mb, display_size, battery_hours) VALUES ($1, $2, $3, $4, $5, $6, $7, $8)",
+                device.name,
+                device.manufacturer,
+                device.release_year,
+                device.cpu,
+                device.ram_mb,
+                device.storage_mb,
+                device.display_size,
+                device.battery_hours
+            )
+        end
+            log.info("Seeding completed", { component = "seed" })
+        end
+    end)
+end
+
+-- Publish to Redis if available (with retry)
+local function publish_event(event_type, data, request_id)
+    for attempt = 1, 3 do
+        local red = get_redis_connection()
+        if red then
+            local event = {
+                event_type = event_type,
+                timestamp = os.time(),
+                request_id = request_id,
+            }
+            for k, v in pairs(data) do
+                event[k] = v
+            end
+
+            local event_json = cjson.encode(event)
+
+            -- Push to queue (worker will consume from this using reliable pattern)
+            red:lpush("devices:events:queue", event_json)
+
+            -- Also publish to Pub/Sub for immediate processing (WebSockets)
+            local count = red:publish("devices:events", event_json)
+
+            log.info("Event published", { event_type = event_type, subscribers = count, request_id = request_id })
+            red:quit()
+            return
+        end
+        if attempt < 3 then socket.sleep(math.min(2 ^ attempt * 0.1, 2)) end
+    end
+    log.warn("Failed to publish event after retries", { event_type = event_type, request_id = request_id })
+end
+
+
+-- Helper to check if a value is JSON null
+local function is_json_null(val)
+    return val == nil or val == cjson.null
+end
+
+-- WebSocket Utils
+local function sha1(data)
+    if digest then
+        return digest.new("sha1"):final(data)
+    end
+    -- Fallback: if luaossl is not available, we can't do a proper handshake
+    -- In a production app, we should ensure it is available.
+    -- NOTE: This fallback doesn't actually produce a SHA1 hash, it just returns data.
+    -- The WebSocket handshake will fail if digest is not available.
+    print("[WS] Warning: openssl.digest not available, SHA1 handshake will fail")
+    return data
+end
+
+local function b64(data)
+    -- Minimal Base64
+    local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
+    return ((data:gsub('.', function(x) 
+        local r,b='',x:byte()
+        for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end
+        return r;
+    end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)
+        if (#x < 6) then return '' end
+        local c=0
+        for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end
+        return b:sub(c+1,c+1)
+    end)..({ '', '==', '=' })[#data%3+1])
+end
+
+local function encode_ws_frame(payload)
+    local header = string.char(0x81) -- FIN + Opcode 1 (text)
+    local len = #payload
+    if len <= 125 then
+        header = header .. string.char(len)
+    elseif len <= 65535 then
+        header = header .. string.char(126) .. string.char(math.floor(len / 256)) .. string.char(len % 256)
+    else
+        -- 64-bit length not implemented for simplicity
+        header = header .. string.char(127) .. string.rep(string.char(0), 4) .. 
+                 string.char(math.floor(len / 16777216) % 256) ..
+                 string.char(math.floor(len / 65536) % 256) ..
+                 string.char(math.floor(len / 256) % 256) ..
+                 string.char(len % 256)
+    end
+    return header .. payload
+end
+
+-- Device Model
+local Device = {}
+
+function Device.all(limit, offset)
+    limit = limit or 10
+    offset = offset or 0
+
+    local res = db.with_connection(function(conn)
+        return conn:query("SELECT * FROM devices ORDER BY id DESC LIMIT $1 OFFSET $2", limit, offset)
+    end)
+    return res or {}
+end
+
+function Device.find(id)
+    local cache_key = "device:" .. id
+    local red = get_redis_connection()
+
+    if red then
+        local cached = red:get(cache_key)
+        if cached then
+            return cjson.decode(cached)
+        end
+    end
+
+    local res = db.with_connection(function(conn)
+        return conn:query("SELECT * FROM devices WHERE id = $1", tonumber(id))
+    end)
+    local row = res and res[1] or nil
+
+    if row and red then
+        red:setex(cache_key, 300, cjson.encode(row))
+    end
+
+    return row
+end
+
+function Device.create(data, request_id)
+    local res = db.with_connection(function(conn)
+        return conn:query(
+            "INSERT INTO devices (name, manufacturer, release_year, cpu, ram_mb, storage_mb, display_size, battery_hours) VALUES ($1, $2, $3, $4, $5, $6, $7, $8) RETURNING id",
+            data.name,
+            data.manufacturer,
+            (not is_json_null(data.release_year)) and tonumber(data.release_year) or nil,
+            (not is_json_null(data.cpu)) and data.cpu or nil,
+            (not is_json_null(data.ram_mb)) and tonumber(data.ram_mb) or nil,
+            (not is_json_null(data.storage_mb)) and tonumber(data.storage_mb) or nil,
+            (not is_json_null(data.display_size)) and data.display_size or nil,
+            (not is_json_null(data.battery_hours)) and tonumber(data.battery_hours) or nil
+        )
+    end)
+    local row = res and res[1]
+    local device_id = row and tonumber(row.id) or nil
+
+    if device_id then
+        publish_event("DevicePublished", { device_id = device_id, device_name = data.name }, request_id)
+        return Device.find(device_id)
+    end
+
+    return nil
+end
+
+function Device.update(id, data, request_id)
+    local updated = false
+    db.with_connection(function(conn)
+        local updates = {}
+        local pg = conn
+        if not is_json_null(data.name) then table.insert(updates, "name = " .. pg:escape_literal(data.name)) end
+        if not is_json_null(data.manufacturer) then table.insert(updates, "manufacturer = " .. pg:escape_literal(data.manufacturer)) end
+        if not is_json_null(data.release_year) then table.insert(updates, "release_year = " .. tonumber(data.release_year)) end
+        if not is_json_null(data.cpu) then table.insert(updates, "cpu = " .. pg:escape_literal(data.cpu)) end
+        if not is_json_null(data.ram_mb) then table.insert(updates, "ram_mb = " .. tonumber(data.ram_mb)) end
+        if not is_json_null(data.storage_mb) then table.insert(updates, "storage_mb = " .. tonumber(data.storage_mb)) end
+        if not is_json_null(data.display_size) then table.insert(updates, "display_size = " .. pg:escape_literal(data.display_size)) end
+        if not is_json_null(data.battery_hours) then table.insert(updates, "battery_hours = " .. tonumber(data.battery_hours)) end
+
+        if #updates > 0 then
+            table.insert(updates, "updated_at = CURRENT_TIMESTAMP")
+            conn:query("UPDATE devices SET " .. table.concat(updates, ", ") .. " WHERE id = $1", tonumber(id))
+            updated = true
+        end
+    end)
+
+    local red = get_redis_connection()
+    if red then
+        red:del("device:" .. id)
+    end
+
+    local device = Device.find(id)
+    if device and updated then
+        publish_event("DeviceUpdated", { device_id = tonumber(id), device_name = device.name }, request_id)
+    end
+    return device
+end
+
+function Device.delete(id, request_id)
+    local device = Device.find(id)
+    db.with_connection(function(conn)
+        conn:query("DELETE FROM devices WHERE id = $1", tonumber(id))
+    end)
+
+    local red = get_redis_connection()
+    if red then
+        red:del("device:" .. id)
+    end
+
+    if device then
+        publish_event("DeviceDeleted", { device_id = tonumber(id), device_name = device.name }, request_id)
+    end
+
+    return true
+end
+
+function Device.get_count()
+    local res = db.with_connection(function(conn)
+        return conn:query("SELECT COUNT(*) as total FROM devices")
+    end)
+    if res and res[1] then
+        return tonumber(res[1].total) or 0
+    end
+    return 0
+end
+
+-- HTTP Request Parser
+local function parse_request(request_line)
+    local method, path, version = request_line:match("^(%w+)%s+(%S+)%s+(%S+)")
+    return method, path, version
+end
+
+local function parse_headers(client)
+    local headers = {}
+    while true do
+        -- Use a small timeout for individual header lines to handle slow clients
+        -- or cases where headers are partially sent.
+        client:settimeout(0.1)
+        local line, err = client:receive("*l")
+        if not line or line == "" then break end
+        local key, value = line:match("^([^:]+):%s*(.*)$")
+        if key then
+            headers[key:lower()] = value
+        end
+    end
+    client:settimeout(0) -- Back to non-blocking
+    return headers
+end
+
+local function parse_query_string(query_str)
+    local params = {}
+    if query_str and query_str ~= "" then
+        for key, value in query_str:gmatch("([^=&]+)=([^&]*)") do
+            params[key] = value
+        end
+    end
+    return params
+end
+
+local function parse_path(full_path)
+    local path, query = full_path:match("^([^?]+)%??(.*)$")
+    return path or full_path, query or ""
+end
+
+local function generate_request_id()
+    return string.format("%x-%x-%x", math.random(0, 0xffff), math.random(0, 0xffff), os.time())
+end
+
+-- HTTP Response Builder
+local function build_response(status, body, content_type, request_id)
+    content_type = content_type or "application/json"
+    local extra_headers = ""
+    if request_id then
+        extra_headers = "X-Request-ID: " .. request_id .. "\r\n"
+    end
+    local response = string.format(
+        "HTTP/1.1 %s\r\n" ..
+        "Content-Type: %s\r\n" ..
+        "Content-Length: %d\r\n" ..
+        "%s" ..
+        "Access-Control-Allow-Origin: *\r\n" ..
+        "Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS\r\n" ..
+        "Access-Control-Allow-Headers: Content-Type, X-Request-ID\r\n" ..
+        "Connection: close\r\n" ..
+        "\r\n" ..
+        "%s",
+        status, content_type, #body, extra_headers, body
+    )
+    return response
+end
+
+-- Route Handlers
+local function handle_get_devices(query_params)
+    local page = tonumber(query_params.page) or 1
+    local per_page = 10
+    local offset = (page - 1) * per_page
+
+    local devices = Device.all(per_page, offset)
+    local total = Device.get_count()
+
+    return "200 OK", cjson.encode({
+        data = devices,
+        total = total,
+        page = page,
+        per_page = per_page
+    })
+end
+
+local function handle_post_devices(json_data, request_id)
+    if not json_data.name or not json_data.manufacturer then
+        return "400 Bad Request", cjson.encode({ error = "Missing required fields: name, manufacturer" })
+    end
+
+    local device = Device.create(json_data, request_id)
+    if device then
+        return "201 Created", cjson.encode(device)
+    else
+        return "500 Internal Server Error", cjson.encode({ error = "Failed to create device" })
+    end
+end
+
+local function handle_get_device(id)
+    local device = Device.find(id)
+    if device then
+        return "200 OK", cjson.encode(device)
+    else
+        return "404 Not Found", cjson.encode({ error = "Device not found" })
+    end
+end
+
+local function handle_put_device(id, json_data, request_id)
+    local device = Device.update(id, json_data, request_id)
+    if device then
+        return "200 OK", cjson.encode(device)
+    else
+        return "404 Not Found", cjson.encode({ error = "Device not found" })
+    end
+end
+
+local function handle_delete_device(id, request_id)
+    Device.delete(id, request_id)
+    return "200 OK", cjson.encode({ success = true })
+end
+
+-- Health: liveness (process alive)
+local function handle_health_live()
+    return "200 OK", cjson.encode({ status = "ok" })
+end
+
+-- Health: readiness (DB + Redis OK)
+local function handle_health_ready()
+    local db_ok = db.ping()
+    local redis_ok = redis_ping()
+    if db_ok and redis_ok then
+        return "200 OK", cjson.encode({ status = "ok", db = "ok", redis = "ok" })
+    end
+    local details = { db = db_ok and "ok" or "fail", redis = redis_ok and "ok" or "fail" }
+    return "503 Service Unavailable", cjson.encode({ status = "degraded", details = details })
+end
+
+-- Main Request Handler
+local function handle_request_with_headers(client, request_line, headers)
+    local method, full_path = parse_request(request_line)
+    local path, query_str = parse_path(full_path)
+    local query_params = parse_query_string(query_str)
+
+    local request_id = headers["x-request-id"] or generate_request_id()
+
+    -- Read body if POST/PUT
+    local body = ""
+    if method == "POST" or method == "PUT" then
+        local content_length = tonumber(headers["content-length"]) or 0
+        if content_length > 0 then
+            body = client:receive(content_length)
+        end
+    end
+
+    -- Parse JSON
+    local json_data = {}
+    if body ~= "" then
+        local ok, data = pcall(cjson.decode, body)
+        if ok then json_data = data end
+    end
+
+    -- Handle CORS preflight
+    if method == "OPTIONS" then
+        client:send(build_response("200 OK", "", nil, request_id))
+        client:close()
+        return
+    end
+
+    -- Route handling
+    local status, response_body = "404 Not Found", cjson.encode({ error = "Not found" })
+
+    if method == "GET" and path == "/devices" then
+        status, response_body = handle_get_devices(query_params)
+    elseif method == "POST" and path == "/devices" then
+        status, response_body = handle_post_devices(json_data, request_id)
+    elseif method == "GET" and path:match("^/devices/%d+$") then
+        local id = path:match("/devices/(%d+)")
+        status, response_body = handle_get_device(id)
+    elseif method == "PUT" and path:match("^/devices/%d+$") then
+        local id = path:match("/devices/(%d+)")
+        status, response_body = handle_put_device(id, json_data, request_id)
+    elseif method == "DELETE" and path:match("^/devices/%d+$") then
+        local id = path:match("/devices/(%d+)")
+        status, response_body = handle_delete_device(id, request_id)
+    elseif method == "GET" and path == "/health" then
+        status, response_body = "200 OK", cjson.encode({ status = "ok" })
+    elseif method == "GET" and path == "/health/live" then
+        status, response_body = handle_health_live()
+    elseif method == "GET" and path == "/health/ready" then
+        status, response_body = handle_health_ready()
+    end
+
+    log.info("Request", {
+        method = method,
+        path = path,
+        status = status:match("^(%d+)") or "?",
+        request_id = request_id,
+    })
+
+    -- Send response
+    local response = build_response(status, response_body, nil, request_id)
+    client:send(response)
+    client:close()
+end
+
+-- Start server
+function app.start()
+    log.info("Handheld Devices API Server starting", {
+        component = "api",
+        port = app.port,
+        db = DB_NAME .. "@" .. DB_HOST .. ":" .. DB_PORT,
+        redis = redis and "enabled" or "disabled",
+    })
+
+    init_db()
+    seed_db()
+
+    local server = socket.bind(app.host, app.port)
+    if not server then
+        error("Failed to bind to " .. app.host .. ":" .. app.port)
+    end
+    server:settimeout(0) -- Non-blocking
+
+    log.info("Server started successfully", { component = "api" })
+
+    local clients = {}
+    local ws_clients = {}
+
+    -- Background Redis subscriber
+    local function connect_subscriber()
+        local red = get_redis_connection()
+        if red then
+            -- Note: redis-lua's subscribe() sets the connection into a subscription state.
+            local ok, err = pcall(function() return red:subscribe("devices:events") end)
+            if ok then
+                -- Set the underlying socket to a very small timeout for non-blocking feel
+                pcall(function()
+                    if red.network and red.network.socket then
+                        red.network.socket:settimeout(0.001)
+                    end
+                end)
+                log.info("Redis subscriber connected", { component = "redis" })
+            else
+                log.error("Redis subscriber failed", { component = "redis", err = tostring(err) })
+                red = nil
+            end
+        end
+        return red
+    end
+
+    local red_sub = connect_subscriber()
+    local last_sub_reconnect = os.time()
+
+    while true do
+        local client = server:accept()
+        if client then
+            client:settimeout(0)
+            table.insert(clients, { socket = client })
+        end
+
+        -- Reconnect subscriber if lost
+        if not red_sub and os.time() - last_sub_reconnect > 5 then
+            red_sub = connect_subscriber()
+            last_sub_reconnect = os.time()
+        end
+
+        -- Handle HTTP clients
+        local to_remove = {}
+        for i, c in ipairs(clients) do
+            local line, err = c.socket:receive("*l")
+            if line then
+                local method, full_path = parse_request(line)
+                local headers = parse_headers(c.socket)
+                
+                if headers["upgrade"] == "websocket" then
+                    -- Handle WebSocket Handshake
+                    local key = headers["sec-websocket-key"]
+                    if key then
+                        local sha1_key = sha1(key .. "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")
+                        local accept = b64(sha1_key)
+                        local response = "HTTP/1.1 101 Switching Protocols\r\n" ..
+                                       "Upgrade: websocket\r\n" ..
+                                       "Connection: Upgrade\r\n" ..
+                                       "Sec-WebSocket-Accept: " .. accept .. "\r\n\r\n"
+                        c.socket:send(response)
+                        table.insert(ws_clients, c.socket)
+                        log.info("WebSocket client connected", { component = "ws", total = #ws_clients })
+                    else
+                        c.socket:close()
+                    end
+                    table.insert(to_remove, i)
+                else
+                    handle_request_with_headers(c.socket, line, headers)
+                    table.insert(to_remove, i)
+                end
+            elseif err == "closed" then
+                table.insert(to_remove, i)
+            end
+        end
+        for i = #to_remove, 1, -1 do table.remove(clients, to_remove[i]) end
+
+        -- Handle Redis Messages -> Send to WS
+        -- redis-lua has no read_reply; pub/sub messages come as multibulk: [kind, channel, payload]
+        if red_sub then
+            local ok, err = pcall(function()
+                local sock = red_sub.network.socket
+                if not sock then return end
+                sock:settimeout(0.001)
+                local line, serr = sock:receive("*l")
+                if not line then
+                    if serr ~= "timeout" then
+                        error(serr or "socket read failed")
+                    end
+                    return
+                end
+                -- Parse RESP: *3\r\n means 3-element array
+                local prefix = line:sub(1, 1)
+                if prefix == "*" then
+                    local count = tonumber(line:sub(2))
+                    if count and count >= 3 then
+                        local parts = {}
+                        for i = 1, count do
+                            local bline, berr = sock:receive("*l")
+                            if not bline then error(berr or "incomplete") end
+                            if bline:sub(1, 1) == "$" then
+                                local len = tonumber(bline:sub(2))
+                                local bulk = len > 0 and sock:receive(len + 2) or ""
+                                if bulk then
+                                    parts[i] = len > 0 and bulk:sub(1, -3) or ""
+                                end
+                            end
+                        end
+                        -- Pub/sub message: ["message", channel, payload]
+                        if parts[1] == "message" and parts[3] then
+                            local payload = parts[3]
+                            log.info("WebSocket broadcast", { component = "ws", payload_len = #tostring(payload) })
+                            local frame = encode_ws_frame(payload)
+                            local closed_ws = {}
+                            for i, ws in ipairs(ws_clients) do
+                                local _, send_err = ws:send(frame)
+                                if send_err then table.insert(closed_ws, i) end
+                            end
+                            for i = #closed_ws, 1, -1 do table.remove(ws_clients, closed_ws[i]) end
+                        end
+                    end
+                end
+            end)
+
+            if not ok then
+                local err_str = tostring(err)
+                if not string.find(err_str, "timeout") and not string.find(err_str, "closed") then
+                    log.error("Redis subscriber error", { component = "redis", err = err_str })
+                    red_sub = nil
+                end
+            end
+        end
+
+        socket.sleep(0.01)
+    end
+end
+
+-- Run if executed directly
+if arg[0]:match("app%-standalone") then
+    app.start()
+end
+
+return app