#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
tests/test_anthropic_service.py
services/anthropic_service.py 單元測試 — Operation Ollama-First v5.0 Phase 7

測試紀律（Phase 7 spec）：
  - generate 正常路徑：cache_creation + cache_read 解析正確
  - generate prompt cache：cache_system=True 時 system 加 cache_control
  - ANTHROPIC_API_KEY 未設定時 is_available() == False
  - SDK ImportError 時不爆（log.error，is_available()=False）
  - SDK 例外時 generate 回 success=False 不 raise
  - cache_hit property 邏輯（cache_read_tokens > 0 → True）
  - check_connection 正常與失敗
"""

from __future__ import annotations

import os
import sys
import logging
from types import SimpleNamespace
from unittest.mock import MagicMock, patch

import pytest

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))


# ─────────────────────────────────────────────────────────────────────────────
# Helpers：仿造 anthropic SDK Response 結構
# ─────────────────────────────────────────────────────────────────────────────

def _fake_anthropic_response(
    text: str = "ok",
    input_tokens: int = 100,
    output_tokens: int = 50,
    cache_creation_input_tokens: int = 0,
    cache_read_input_tokens: int = 0,
    model: str = "claude-opus-4-7",
):
    """模擬 anthropic.types.Message"""
    block = SimpleNamespace(text=text, type="text")
    usage = SimpleNamespace(
        input_tokens=input_tokens,
        output_tokens=output_tokens,
        cache_creation_input_tokens=cache_creation_input_tokens,
        cache_read_input_tokens=cache_read_input_tokens,
    )
    return SimpleNamespace(content=[block], usage=usage, model=model)


@pytest.fixture
def mock_sdk(monkeypatch):
    """模擬 anthropic SDK：注入 fake module 到 sys.modules，
    讓 AnthropicService._init_client 走 import anthropic 成功路徑。"""
    fake_anthropic = MagicMock()
    fake_client = MagicMock()
    fake_anthropic.Anthropic.return_value = fake_client
    monkeypatch.setitem(sys.modules, 'anthropic', fake_anthropic)
    return fake_anthropic, fake_client


# ─────────────────────────────────────────────────────────────────────────────
# is_available() 測試
# ─────────────────────────────────────────────────────────────────────────────

def test_is_available_false_when_no_api_key(monkeypatch):
    """ANTHROPIC_API_KEY 未設 → is_available() False"""
    monkeypatch.delenv('ANTHROPIC_API_KEY', raising=False)
    # reload 確保模組層 ANTHROPIC_API_KEY 重新讀取
    import importlib
    import services.anthropic_service as svc_mod
    importlib.reload(svc_mod)
    svc = svc_mod.AnthropicService(api_key='')
    assert svc.is_available() is False


def test_is_available_true_when_sdk_ready(mock_sdk):
    """API key + SDK 都有 → is_available() True"""
    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')
    assert svc.is_available() is True


def test_is_available_logs_cost_throttle_failure(mock_sdk, monkeypatch, caplog):
    """cost_throttle 檢查故障時仍維持 Claude 可用，但必須留下診斷 log。"""
    from services.anthropic_service import AnthropicService
    import services.cost_throttle_service as cost_throttle_service

    def _raise_cost_throttle_error(provider):
        raise RuntimeError("cost throttle unavailable")

    monkeypatch.setattr(
        cost_throttle_service,
        "is_provider_throttled",
        _raise_cost_throttle_error,
    )
    caplog.set_level(logging.WARNING, logger="services.anthropic_service")

    svc = AnthropicService(api_key='sk-ant-test')

    assert svc.is_available() is True
    assert "cost_throttle check failed" in caplog.text


def test_is_available_false_on_import_error(monkeypatch):
    """SDK 未安裝（ImportError）→ is_available() False，不 raise"""
    # 移除 anthropic 模組讓 import 失敗
    monkeypatch.setitem(sys.modules, 'anthropic', None)
    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')
    assert svc.is_available() is False


def test_is_available_false_on_init_exception(monkeypatch):
    """SDK 初始化拋例外 → is_available() False，不 raise"""
    fake_anthropic = MagicMock()
    fake_anthropic.Anthropic.side_effect = RuntimeError("auth failed")
    monkeypatch.setitem(sys.modules, 'anthropic', fake_anthropic)

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')
    assert svc.is_available() is False


# ─────────────────────────────────────────────────────────────────────────────
# generate() 正常路徑
# ─────────────────────────────────────────────────────────────────────────────

def test_generate_success_basic(mock_sdk):
    """generate 正常路徑：tokens 正確解析"""
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.return_value = _fake_anthropic_response(
        text="hello world",
        input_tokens=120,
        output_tokens=40,
    )

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')

    resp = svc.generate(prompt="say hi", max_tokens=100)
    assert resp.success is True
    assert resp.content == "hello world"
    assert resp.input_tokens == 120
    assert resp.output_tokens == 40
    assert resp.cache_creation_tokens == 0
    assert resp.cache_read_tokens == 0
    assert resp.cache_hit is False
    assert resp.duration_ms >= 0
    assert resp.error is None


def test_generate_with_cache_creation_and_read(mock_sdk):
    """generate 解析 cache_creation_input_tokens / cache_read_input_tokens"""
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.return_value = _fake_anthropic_response(
        cache_creation_input_tokens=500,
        cache_read_input_tokens=2000,
    )

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')

    resp = svc.generate(prompt="reuse", system_prompt="stable system")
    assert resp.success is True
    assert resp.cache_creation_tokens == 500
    assert resp.cache_read_tokens == 2000
    assert resp.cache_hit is True


def test_generate_with_cache_system_adds_cache_control(mock_sdk):
    """cache_system=True 時 system_prompt 帶 ephemeral cache_control"""
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.return_value = _fake_anthropic_response()

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')

    svc.generate(
        prompt="user",
        system_prompt="my-system",
        cache_system=True,
    )
    _, kwargs = fake_client.messages.create.call_args
    assert isinstance(kwargs['system'], list)
    assert kwargs['system'][0]['type'] == 'text'
    assert kwargs['system'][0]['text'] == 'my-system'
    assert kwargs['system'][0]['cache_control'] == {"type": "ephemeral"}


def test_generate_without_cache_system_uses_string(mock_sdk):
    """cache_system=False 時 system 為純字串"""
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.return_value = _fake_anthropic_response()

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')

    svc.generate(prompt="user", system_prompt="my-system", cache_system=False)
    _, kwargs = fake_client.messages.create.call_args
    assert kwargs['system'] == 'my-system'


def test_generate_without_system_prompt(mock_sdk):
    """無 system_prompt 時 kwargs 不含 system"""
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.return_value = _fake_anthropic_response()

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')

    svc.generate(prompt="user")
    _, kwargs = fake_client.messages.create.call_args
    assert 'system' not in kwargs


def test_generate_passes_temperature_and_max_tokens(mock_sdk):
    """temperature / max_tokens / model 正確傳給 SDK"""
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.return_value = _fake_anthropic_response()

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')

    svc.generate(
        prompt="x", model="claude-sonnet-4-6",
        max_tokens=2048, temperature=0.5,
    )
    _, kwargs = fake_client.messages.create.call_args
    assert kwargs['model'] == 'claude-sonnet-4-6'
    assert kwargs['max_tokens'] == 2048
    assert kwargs['temperature'] == 0.5
    assert kwargs['messages'] == [{"role": "user", "content": "x"}]


# ─────────────────────────────────────────────────────────────────────────────
# generate() 失敗路徑
# ─────────────────────────────────────────────────────────────────────────────

def test_generate_returns_failure_when_no_client(monkeypatch):
    """無 API key → generate 回 success=False 不 raise"""
    monkeypatch.delenv('ANTHROPIC_API_KEY', raising=False)
    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='')

    resp = svc.generate(prompt="x")
    assert resp.success is False
    assert resp.content == ""
    assert "not initialized" in (resp.error or "")


def test_generate_handles_sdk_exception(mock_sdk):
    """SDK 拋例外 → generate 回 success=False，error 含 type+msg"""
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.side_effect = RuntimeError("rate limit")

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')

    resp = svc.generate(prompt="x")
    assert resp.success is False
    assert "RuntimeError" in (resp.error or "")
    assert "rate limit" in (resp.error or "")
    assert resp.duration_ms >= 0


# ─────────────────────────────────────────────────────────────────────────────
# ClaudeResponse cache_hit property
# ─────────────────────────────────────────────────────────────────────────────

def test_cache_hit_property():
    from services.anthropic_service import ClaudeResponse
    assert ClaudeResponse(success=True, content="x", model="m",
                          cache_read_tokens=0).cache_hit is False
    assert ClaudeResponse(success=True, content="x", model="m",
                          cache_read_tokens=1).cache_hit is True
    assert ClaudeResponse(success=True, content="x", model="m",
                          cache_read_tokens=10000).cache_hit is True


def test_total_tokens_property():
    from services.anthropic_service import ClaudeResponse
    r = ClaudeResponse(success=True, content="x", model="m",
                       input_tokens=100, output_tokens=50)
    assert r.total_tokens == 150


# ─────────────────────────────────────────────────────────────────────────────
# check_connection
# ─────────────────────────────────────────────────────────────────────────────

def test_check_connection_success(mock_sdk):
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.return_value = _fake_anthropic_response(text="pong")

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')
    assert svc.check_connection() is True


def test_check_connection_fail_no_client(monkeypatch):
    monkeypatch.delenv('ANTHROPIC_API_KEY', raising=False)
    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='')
    assert svc.check_connection() is False


def test_check_connection_fail_on_sdk_error(mock_sdk):
    fake_anthropic, fake_client = mock_sdk
    fake_client.messages.create.side_effect = RuntimeError("boom")

    from services.anthropic_service import AnthropicService
    svc = AnthropicService(api_key='sk-ant-test')
    assert svc.check_connection() is False


# ─────────────────────────────────────────────────────────────────────────────
# COST_TABLE 整合（確認 ai_call_logger 認得 claude 模型）
# ─────────────────────────────────────────────────────────────────────────────

def test_cost_table_has_claude_models():
    from services.ai_call_logger import COST_TABLE, _calc_cost
    assert 'claude-opus-4-7' in COST_TABLE
    assert 'claude-sonnet-4-6' in COST_TABLE
    assert 'claude-haiku-4-5' in COST_TABLE
    # opus 1M in/1M out 應為 15 + 75 = 90 USD
    assert abs(_calc_cost('claude-opus-4-7', 1_000_000, 1_000_000) - 90.0) < 1e-6
    # haiku 1M in/1M out 應為 0.8 + 4.0 = 4.8 USD
    assert abs(_calc_cost('claude-haiku-4-5', 1_000_000, 1_000_000) - 4.8) < 1e-6