import importlib
import json
import sys
from pathlib import Path

from fastapi.testclient import TestClient


ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))


def load_app_module(monkeypatch, *, skip_model_load=True, ollama_model=None, service_token=None, external_ai_enabled=False):
    if skip_model_load:
        monkeypatch.setenv("AI_SERVICE_SKIP_MODEL_LOAD", "1")
    else:
        monkeypatch.delenv("AI_SERVICE_SKIP_MODEL_LOAD", raising=False)
    monkeypatch.delenv("AI_SERVICE_EAGER_MODEL_LOAD", raising=False)
    # Default to keyless so the existing suite is unaffected by a token in the dev shell.
    if service_token is None:
        monkeypatch.delenv("AI_SERVICE_TOKEN", raising=False)
    else:
        monkeypatch.setenv("AI_SERVICE_TOKEN", service_token)
    if ollama_model is None:
        monkeypatch.delenv("OLLAMA_MODEL", raising=False)
    else:
        monkeypatch.setenv("OLLAMA_MODEL", ollama_model)
    if external_ai_enabled:
        monkeypatch.setenv("EXTERNAL_AI_ENABLED", "true")
    else:
        monkeypatch.delenv("EXTERNAL_AI_ENABLED", raising=False)
    if "app" in sys.modules:
        del sys.modules["app"]
    module = importlib.import_module("app")
    return importlib.reload(module)


def test_health_reports_runtime_without_ollama_and_without_forcing_model_load(monkeypatch):
    module = load_app_module(monkeypatch)
    client = TestClient(module.app)

    response = client.get("/health")

    assert response.status_code == 200
    payload = response.json()
    assert payload["ok"] is True
    assert payload["device"] == "cpu"
    assert payload["model_loaded"] is False
    assert payload["model_disabled"] is True
    assert payload["summarize_available"] is False
    assert "disabled" in payload["model_load_error"].lower()
    assert payload["ollama_configured"] is False
    assert payload["ollama_model"] is None
    assert payload["ollama_installed_models"] == []
    assert payload["ollama_loaded_models"] == []


def test_summarize_returns_503_with_explicit_reason_when_model_loading_is_disabled(monkeypatch):
    module = load_app_module(monkeypatch)
    client = TestClient(module.app)

    response = client.post("/summarize", json={"text": "Platform engineering role with APIs and Python experience."})

    assert response.status_code == 503
    payload = response.json()
    assert "disabled" in payload["detail"].lower()


def test_health_reports_ollama_unreachable_when_configured_but_not_available(monkeypatch):
    module = load_app_module(monkeypatch, ollama_model="qwen2.5:7b")

    def boom(path: str):
        raise OSError("connection refused")

    monkeypatch.setattr(module, "_ollama_json", boom)
    client = TestClient(module.app)

    response = client.get("/health")

    assert response.status_code == 200
    payload = response.json()
    assert payload["ollama_configured"] is True
    assert payload["ollama_reachable"] is False
    assert payload["ollama_model"] == "qwen2.5:7b"
    assert payload["ollama_model_available"] is False


def test_rewrite_cv_returns_plain_rewritten_text(monkeypatch):
    module = load_app_module(monkeypatch, ollama_model="qwen2.5:7b")
    monkeypatch.setattr(module, "_ollama_generate_text", lambda prompt: "# Professional Summary\nBuilt resilient backend systems.\n\n# Skills\n- C#\n- .NET")
    client = TestClient(module.app)

    response = client.post("/cv/rewrite", json={
        "instruction": "Rewrite this CV into a cleaner master CV.",
        "text": "Professional Summary\nBuilt backend systems.",
        "max_length": 220,
        "min_length": 80,
    })

    assert response.status_code == 200
    payload = response.json()
    assert payload["rewritten_text"].startswith("# Professional Summary")
    assert "Role summary:" not in payload["rewritten_text"]


def test_classify_block_returns_structured_json(monkeypatch):
    module = load_app_module(monkeypatch)

    def fake_generate_json(prompt: str):
        assert "Senior Platform Engineer" in prompt
        return {
            "section": "Work Experience",
            "confidence": 0.91,
            "reason": "job block",
            "title": "Senior Platform Engineer",
            "company": "Atlas Systems",
            "location": "Oslo",
            "start": "2019",
            "end": "Present",
            "bullets": ["Built event-driven APIs and migration tooling."],
            "summary": [],
            "skills": ["Python", "SQL"],
        }

    monkeypatch.setattr(module, "_ollama_generate_json", fake_generate_json)
    client = TestClient(module.app)

    response = client.post("/cv/classify-block", json={"block": "Senior Platform Engineer at Atlas Systems, Oslo, 2019 - Present. Built event-driven APIs and migration tooling."})

    assert response.status_code == 200
    payload = response.json()
    assert payload["section"] == "Work Experience"
    assert payload["title"] == "Senior Platform Engineer"
    assert payload["company"] == "Atlas Systems"
    assert payload["bullets"] == ["Built event-driven APIs and migration tooling."]
    assert payload["summary"] == []
    assert payload["skills"] == ["Python", "SQL"]


def test_classify_block_supports_projects_section(monkeypatch):
    # Phase 2.1-b: Projects and Certifications are now valid classified sections so project blocks
    # (e.g. the benchmark CV's JobTrack/InboxIntel) are no longer dropped into "Other".
    module = load_app_module(monkeypatch)

    def fake_generate_json(prompt: str):
        assert "Projects" in prompt  # the enum now advertises Projects to the model
        return {
            "section": "Projects",
            "confidence": 0.83,
            "reason": "project block",
            "title": "JobTrack",
            "company": None,
            "location": None,
            "start": None,
            "end": None,
            "bullets": ["Full-stack job-application tracker (React, ASP.NET Core, SQLite, Docker)."],
            "summary": [],
            "skills": [],
        }

    monkeypatch.setattr(module, "_ollama_generate_json", fake_generate_json)
    client = TestClient(module.app)

    response = client.post("/cv/classify-block", json={"block": "JobTrack - Full-stack job-application tracker (React, ASP.NET Core, SQLite, Docker)."})

    assert response.status_code == 200
    payload = response.json()
    assert payload["section"] == "Projects"
    assert payload["title"] == "JobTrack"


def test_classify_block_defaults_missing_section_to_other(monkeypatch):
    module = load_app_module(monkeypatch)
    monkeypatch.setattr(module, "_ollama_generate_json", lambda prompt: {"bullets": []})
    client = TestClient(module.app)

    response = client.post("/cv/classify-block", json={"block": "Miscellaneous profile text"})

    assert response.status_code == 200
    payload = response.json()
    assert payload["section"] == "Other"
    assert payload["bullets"] == []
    assert payload["summary"] == []
    assert payload["skills"] == []


# --- AI provider router -------------------------------------------------------

class _FakeResponse:
    def __init__(self, payload):
        self._data = json.dumps(payload).encode("utf-8")

    def read(self):
        return self._data

    def __enter__(self):
        return self

    def __exit__(self, *exc):
        return False


def _install_fake_urlopen(monkeypatch, module, response_payload, captured):
    def fake_urlopen(req, timeout=None):
        captured["url"] = req.full_url
        captured["headers"] = {k.lower(): v for k, v in req.header_items()}
        captured["body"] = json.loads(req.data.decode("utf-8"))
        return _FakeResponse(response_payload)

    monkeypatch.setattr(module.urllib_request, "urlopen", fake_urlopen)


def test_provider_defaults_to_ollama_and_is_unchanged(monkeypatch):
    monkeypatch.delenv("AI_PROVIDER", raising=False)
    monkeypatch.setenv("OLLAMA_BASE_URL", "http://ollama-host:11434")
    module = load_app_module(monkeypatch, ollama_model="qwen2.5:7b")
    assert module.AI_PROVIDER == "ollama"

    captured = {}
    _install_fake_urlopen(monkeypatch, module, {"response": '{"score": 7}'}, captured)

    assert module._ollama_generate_json("hi") == {"score": 7}
    assert captured["url"] == "http://ollama-host:11434/api/generate"
    assert captured["body"]["model"] == "qwen2.5:7b"
    assert captured["body"]["format"] == "json"
    assert captured["body"]["options"]["temperature"] == 0.1


def test_provider_gemini_dispatch(monkeypatch):
    monkeypatch.setenv("AI_PROVIDER", "gemini")
    monkeypatch.setenv("GEMINI_API_KEY", "test-key")
    monkeypatch.setenv("GEMINI_MODEL", "gemini-2.0-flash")
    module = load_app_module(monkeypatch, external_ai_enabled=True)
    module._external_ai_allowed.set(True)

    captured = {}
    payload = {"candidates": [{"content": {"parts": [{"text": '{"score": 9}'}]}}]}
    _install_fake_urlopen(monkeypatch, module, payload, captured)

    assert module._ollama_generate_json("hi") == {"score": 9}
    assert "generativelanguage" in captured["url"]
    assert "gemini-2.0-flash:generateContent" in captured["url"]
    assert "key=" not in captured["url"]  # key must not be in the URL
    assert captured["headers"].get("x-goog-api-key") == "test-key"
    assert captured["body"]["generationConfig"]["responseMimeType"] == "application/json"


def test_provider_groq_dispatch(monkeypatch):
    monkeypatch.setenv("AI_PROVIDER", "groq")
    monkeypatch.setenv("GROQ_API_KEY", "test-key")
    module = load_app_module(monkeypatch, external_ai_enabled=True)
    module._external_ai_allowed.set(True)

    captured = {}
    payload = {"choices": [{"message": {"content": "rewritten CV text"}}]}
    _install_fake_urlopen(monkeypatch, module, payload, captured)

    assert module._ollama_generate_text("rewrite this") == "rewritten CV text"
    assert captured["url"].endswith("/chat/completions")
    assert captured["headers"].get("authorization") == "Bearer test-key"
    assert captured["body"]["messages"][0]["content"] == "rewrite this"


def test_provider_missing_cloud_key_raises_503(monkeypatch):
    monkeypatch.setenv("AI_PROVIDER", "gemini")
    monkeypatch.delenv("GEMINI_API_KEY", raising=False)
    module = load_app_module(monkeypatch, external_ai_enabled=True)
    module._external_ai_allowed.set(True)

    from fastapi import HTTPException

    try:
        module._ollama_generate_json("hi")
    except HTTPException as ex:
        assert ex.status_code == 503
        assert "GEMINI_API_KEY" in ex.detail
    else:
        raise AssertionError("expected HTTPException for missing GEMINI_API_KEY")


def test_health_reports_active_provider(monkeypatch):
    monkeypatch.setenv("AI_PROVIDER", "gemini")
    monkeypatch.setenv("GEMINI_API_KEY", "test-key")
    module = load_app_module(monkeypatch)
    client = TestClient(module.app)

    payload = client.get("/health").json()

    assert payload["ai_provider"] == "gemini"
    assert payload["ai_provider_configured"] is True


def test_external_provider_requires_admin_gate_and_backend_consent_header(monkeypatch):
    monkeypatch.setenv("AI_PROVIDER", "gemini")
    monkeypatch.setenv("GEMINI_API_KEY", "test-key")
    module = load_app_module(monkeypatch, ollama_model="qwen2.5:7b", external_ai_enabled=True)
    captured = {}
    _install_fake_urlopen(monkeypatch, module, {"response": "rewritten locally"}, captured)
    client = TestClient(module.app)

    local_response = client.post("/cv/rewrite", json={"instruction": "Rewrite", "text": "Synthetic CV"})
    assert local_response.status_code == 200
    assert captured["url"].startswith("http://127.0.0.1:11434/")
    assert local_response.headers["X-Ai-Provider"] == "ollama"

    external_payload = {"candidates": [{"content": {"parts": [{"text": "rewritten externally"}]}}]}
    _install_fake_urlopen(monkeypatch, module, external_payload, captured)
    external_response = client.post(
        "/cv/rewrite",
        json={"instruction": "Rewrite", "text": "Synthetic CV"},
        headers={"X-Ai-External-Allowed": "true"},
    )
    assert external_response.status_code == 200
    assert "generativelanguage" in captured["url"]
    assert external_response.headers["X-Ai-Provider"] == "gemini"


def test_service_token_rejects_calls_without_the_header(monkeypatch):
    module = load_app_module(monkeypatch, service_token="s3cret")
    client = TestClient(module.app)

    response = client.post("/summarize", json={"text": "Platform engineering role."})

    assert response.status_code == 401
    assert "token" in response.json()["detail"].lower()


def test_service_token_rejects_a_wrong_header(monkeypatch):
    module = load_app_module(monkeypatch, service_token="s3cret")
    client = TestClient(module.app)

    response = client.post(
        "/summarize",
        json={"text": "Platform engineering role."},
        headers={"X-Ai-Service-Token": "wrong"},
    )

    assert response.status_code == 401


def test_service_token_allows_the_correct_header(monkeypatch):
    module = load_app_module(monkeypatch, service_token="s3cret")
    client = TestClient(module.app)

    response = client.post(
        "/summarize",
        json={"text": "Platform engineering role."},
        headers={"X-Ai-Service-Token": "s3cret"},
    )

    # 503 = passed the token gate and reached the handler, which is model-disabled here.
    assert response.status_code == 503


def test_health_stays_open_so_probes_and_healthchecks_work(monkeypatch):
    module = load_app_module(monkeypatch, service_token="s3cret")
    client = TestClient(module.app)

    assert client.get("/health").status_code == 200


def test_endpoints_stay_open_when_no_token_is_configured(monkeypatch):
    module = load_app_module(monkeypatch)
    client = TestClient(module.app)

    # Keyless local dev: reaches the handler (503 model-disabled), not a 401.
    response = client.post("/summarize", json={"text": "Platform engineering role."})

    assert response.status_code == 503