feat(04-02): add script download API endpoints and router registration

- imptune/api/scripts.py: GET /printers/{id}/scripts/{install,uninstall,detect}
- 404 for missing printer, 422 for missing driver/INF/driver_desc
- Content-Disposition attachment header on all responses
- imptune/main.py: register scripts.router
- 5 integration tests covering all endpoint cases (200/404/422)

imptune/api/scripts.py

@@ -0,0 +1,94 @@
+"""Script download endpoints — generates and serves PowerShell scripts for a printer."""
+import json
+
+from fastapi import APIRouter
+from fastapi.responses import PlainTextResponse
+
+from imptune.db.models import Printer
+from imptune.generators.script_generator import render_detect, render_install, render_uninstall
+
+router = APIRouter(prefix="/printers")
+
+
+def _get_printer_and_driver(printer_id: int):
+    """Fetch printer and validate driver — returns (printer, driver_name) or PlainTextResponse error."""
+    printer = Printer.get_or_none(Printer.id == printer_id)
+    if printer is None:
+        return None, PlainTextResponse("Printer not found", status_code=404)
+
+    driver = printer.driver
+    if driver is None:
+        return None, PlainTextResponse("No driver assigned", status_code=422)
+
+    if not driver.inf_filename:
+        return None, PlainTextResponse("Driver has no INF file", status_code=422)
+
+    if not driver.driver_desc:
+        return None, PlainTextResponse("Driver has no description", status_code=422)
+
+    try:
+        desc_list = json.loads(driver.driver_desc)
+        driver_name = desc_list[0]
+    except (json.JSONDecodeError, IndexError, TypeError):
+        return None, PlainTextResponse("Driver description is invalid", status_code=422)
+
+    return (printer, driver, driver_name), None
+
+
+@router.get("/{printer_id}/scripts/install")
+def get_install_script(printer_id: int):
+    """Download the PowerShell install script for a printer."""
+    result, error = _get_printer_and_driver(printer_id)
+    if error is not None:
+        return error
+
+    printer, driver, driver_name = result
+    rendered = render_install(
+        printer_name=printer.name,
+        ip_address=printer.ip_address,
+        port_name=printer.port_name,
+        driver_name=driver_name,
+        inf_filename=driver.inf_filename,
+        duplex_mode=printer.duplex_mode,
+        color_mode=printer.color_mode,
+        paper_size=printer.paper_size,
+        collate=printer.collate,
+    )
+    return PlainTextResponse(
+        content=rendered,
+        headers={"Content-Disposition": 'attachment; filename="install.ps1"'},
+    )
+
+
+@router.get("/{printer_id}/scripts/uninstall")
+def get_uninstall_script(printer_id: int):
+    """Download the PowerShell uninstall script for a printer."""
+    result, error = _get_printer_and_driver(printer_id)
+    if error is not None:
+        return error
+
+    printer, driver, driver_name = result
+    rendered = render_uninstall(
+        printer_name=printer.name,
+        driver_name=driver_name,
+        port_name=printer.port_name,
+    )
+    return PlainTextResponse(
+        content=rendered,
+        headers={"Content-Disposition": 'attachment; filename="uninstall.ps1"'},
+    )
+
+
+@router.get("/{printer_id}/scripts/detect")
+def get_detect_script(printer_id: int):
+    """Download the PowerShell detection script for a printer."""
+    result, error = _get_printer_and_driver(printer_id)
+    if error is not None:
+        return error
+
+    printer, driver, driver_name = result
+    rendered = render_detect(printer_name=printer.name)
+    return PlainTextResponse(
+        content=rendered,
+        headers={"Content-Disposition": 'attachment; filename="detect.ps1"'},
+    )

imptune/main.py

@@ -5,7 +5,7 @@ from pathlib import Path
 from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 
-from imptune.api import clients, drivers, health, pages, printers
+from imptune.api import clients, drivers, health, pages, printers, scripts
 from imptune.config import DATA_DIR, DRIVERS_DIR
 from imptune.db.database import db, init_db
 
@@ -33,3 +33,4 @@ app.include_router(pages.router)
 app.include_router(drivers.router)
 app.include_router(printers.router)
 app.include_router(clients.router)
+app.include_router(scripts.router)

tests/test_script_generator.py

@@ -3,6 +3,30 @@ import pytest
 from imptune.generators.script_generator import render_detect, render_install, render_uninstall
 
 
+def _create_test_driver_and_printer():
+    """Helper: create a Driver + Printer for integration tests."""
+    from imptune.db.models import Driver, Printer
+
+    driver = Driver.create(
+        sha256="abc123",
+        original_filename="test.zip",
+        size_bytes=100,
+        driver_desc='["Test Driver"]',
+        inf_filename="test.inf",
+    )
+    printer = Printer.create(
+        name="Test Printer",
+        ip_address="10.0.0.1",
+        port_name="IP_10.0.0.1",
+        driver=driver,
+        duplex_mode="LongEdge",
+        color_mode=True,
+        paper_size="A4",
+        collate=True,
+    )
+    return driver, printer
+
+
 SAMPLE_ARGS = dict(
     printer_name="HP LaserJet 4000",
     ip_address="192.168.1.10",
@@ -118,3 +142,56 @@ def test_render_detect():
     assert "Write-Output" in result
     assert "exit 0" in result
     assert "exit 1" in result
+
+
+# ---------------------------------------------------------------------------
+# Integration tests — script API endpoints
+# ---------------------------------------------------------------------------
+
+
+def test_install_endpoint(client):
+    """GET /printers/{id}/scripts/install returns 200 with pnputil in content."""
+    _driver, printer = _create_test_driver_and_printer()
+    response = client.get(f"/printers/{printer.id}/scripts/install")
+    assert response.status_code == 200
+    assert "pnputil" in response.text
+
+
+def test_uninstall_endpoint(client):
+    """GET /printers/{id}/scripts/uninstall returns 200 with Remove-Printer in content."""
+    _driver, printer = _create_test_driver_and_printer()
+    response = client.get(f"/printers/{printer.id}/scripts/uninstall")
+    assert response.status_code == 200
+    assert "Remove-Printer" in response.text
+
+
+def test_detect_endpoint(client):
+    """GET /printers/{id}/scripts/detect returns 200 with Write-Output in content."""
+    _driver, printer = _create_test_driver_and_printer()
+    response = client.get(f"/printers/{printer.id}/scripts/detect")
+    assert response.status_code == 200
+    assert "Write-Output" in response.text
+
+
+def test_script_endpoint_missing_printer(client):
+    """GET /printers/{id}/scripts/install returns 404 for nonexistent printer."""
+    response = client.get("/printers/9999/scripts/install")
+    assert response.status_code == 404
+
+
+def test_script_endpoint_no_driver(client):
+    """GET /printers/{id}/scripts/install returns 422 when no driver assigned."""
+    from imptune.db.models import Printer
+
+    printer = Printer.create(
+        name="No Driver Printer",
+        ip_address="10.0.0.2",
+        port_name="IP_10.0.0.2",
+        driver=None,
+        duplex_mode="OneSided",
+        color_mode=True,
+        paper_size="A4",
+        collate=True,
+    )
+    response = client.get(f"/printers/{printer.id}/scripts/install")
+    assert response.status_code == 422