"""
tests/test_ollama_retry_chain.py
─────────────────────────────────────────────────────────────────
Operation Ollama-First v5.0 / Phase 13 補強 — 三主機 retry 鏈驗證

驗證 hotfix e862a90 (generate retry) + 6572d52 (embed retry) 的邏輯：
  1. self.host @property lazy resolve
  2. generate / generate_embedding 失敗自動 retry 下一台主機（最多 3 次）
  3. mark_unhealthy 後下次 self.host 取新主機
  4. caller 顯式 host=... 凍結不 retry
  5. 三主機都失敗 → return failure（不無限迴圈）
  6. Phase 13 補強：OllamaResponse.input_tokens/output_tokens 解析

紀律：不打真實 Ollama，全 mock requests.post。
"""

from unittest.mock import patch, MagicMock

import pytest


# ═══════════════════════════════════════════════════════════════════════════
# Fixtures
# ═══════════════════════════════════════════════════════════════════════════

@pytest.fixture(autouse=True)
def _reset_state():
    """每 test 清 unhealthy marks + resolve cache"""
    import services.ollama_service as oss
    oss._unhealthy_marks.clear()
    oss._resolved_host_cache['host'] = None
    oss._resolved_host_cache['ts'] = 0
    yield
    oss._unhealthy_marks.clear()
    oss._resolved_host_cache['host'] = None
    oss._resolved_host_cache['ts'] = 0


# ═══════════════════════════════════════════════════════════════════════════
# T1: self.host 改 @property（不再凍結 instance）
# ═══════════════════════════════════════════════════════════════════════════

def test_self_host_is_lazy_property_not_frozen():
    """OllamaService.host 應為 property，每次存取走 resolve_ollama_host()"""
    from services.ollama_service import OllamaService

    svc = OllamaService()
    # property 不在 __init__ 凍結
    assert svc._explicit_host is None

    # 存取 .host 走 resolve
    with patch('services.ollama_service.resolve_ollama_host', return_value='http://test:11434') as mock_resolve:
        h1 = svc.host
        h2 = svc.host
    assert h1 == h2 == 'http://test:11434'
    assert mock_resolve.call_count >= 2  # 每次 access 都呼叫


def test_explicit_host_freezes():
    """caller 顯式傳 host → _explicit_host 凍結，不走 lazy resolve"""
    from services.ollama_service import OllamaService

    svc = OllamaService(host='http://explicit:11434')
    assert svc._explicit_host == 'http://explicit:11434'

    with patch('services.ollama_service.resolve_ollama_host') as mock_resolve:
        h = svc.host
    assert h == 'http://explicit:11434'
    mock_resolve.assert_not_called()


# ═══════════════════════════════════════════════════════════════════════════
# T2: generate 三主機 retry 鏈（核心 hotfix e862a90）
# ═══════════════════════════════════════════════════════════════════════════

def test_generate_retries_on_first_host_timeout():
    """第一台 timeout → mark_unhealthy → 第二台成功"""
    import requests
    from services.ollama_service import OllamaService

    svc = OllamaService()

    # 序列：第一次 timeout，第二次成功
    fake_ok = MagicMock(status_code=200)
    fake_ok.json.return_value = {
        'response': 'OK from secondary',
        'prompt_eval_count': 100, 'eval_count': 50,
    }
    call_results = [requests.Timeout('first host'), fake_ok]

    # mock host property 回傳兩台不同主機
    hosts = ['http://host1:11434', 'http://host2:11434']

    with patch('services.ollama_service.resolve_ollama_host', side_effect=hosts), \
         patch('services.ollama_service.requests.post', side_effect=call_results) as mock_post:
        resp = svc.generate('test prompt')

    assert resp.success is True
    assert resp.content == 'OK from secondary'
    assert resp.input_tokens == 100
    assert resp.output_tokens == 50
    assert mock_post.call_count == 2  # 第一次 timeout, 第二次成功


def test_generate_all_three_hosts_fail_returns_failure():
    """三主機都失敗 → success=False，不無限迴圈"""
    import requests
    from services.ollama_service import OllamaService

    svc = OllamaService()
    hosts = ['http://h1:11434', 'http://h2:11434', 'http://h3:11434']

    with patch('services.ollama_service.resolve_ollama_host', side_effect=hosts), \
         patch('services.ollama_service.requests.post',
               side_effect=requests.Timeout('all timeout')) as mock_post:
        resp = svc.generate('test')

    assert resp.success is False
    assert mock_post.call_count == 3  # 試了 3 次
    assert 'all 3 hosts failed' in (resp.error or '')


def test_generate_same_host_breaks_loop():
    """resolve 連 3 次回同主機（cache 沒過期）→ 不無限迴圈"""
    import requests
    from services.ollama_service import OllamaService

    svc = OllamaService()
    same_host = 'http://stuck:11434'

    with patch('services.ollama_service.resolve_ollama_host', return_value=same_host), \
         patch('services.ollama_service.requests.post',
               side_effect=requests.Timeout('stuck')) as mock_post:
        resp = svc.generate('test')

    assert resp.success is False
    # 第一次試 stuck → 失敗 → 第二次 self.host 還是 stuck（cache 還在）→ break
    assert mock_post.call_count == 1


def test_generate_forces_final_fallback_when_unhealthy_ttl_expires_mid_request():
    """長 timeout 期間 unhealthy TTL 過期時，第三輪仍應打 111 fallback。"""
    import requests
    from services import ollama_service as oss
    from services.ollama_service import OllamaService

    svc = OllamaService()
    hosts = [
        oss.OLLAMA_HOST_PRIMARY,
        oss.OLLAMA_HOST_SECONDARY,
        oss.OLLAMA_HOST_PRIMARY,  # 模擬 primary unhealthy mark 過期後 resolver 又選回 primary
    ]

    with patch('services.ollama_service.resolve_ollama_host', side_effect=hosts), \
         patch('services.ollama_service.requests.post',
               side_effect=requests.Timeout('all timeout')) as mock_post:
        resp = svc.generate('test')

    posted_hosts = [call.args[0].split('/api/generate')[0] for call in mock_post.call_args_list]
    assert resp.success is False
    assert mock_post.call_count == 3
    assert posted_hosts == [oss.OLLAMA_HOST_PRIMARY, oss.OLLAMA_HOST_SECONDARY, oss.OLLAMA_HOST_FALLBACK]
    assert 'all 3 hosts failed' in (resp.error or '')


def test_generate_token_parsing_phase13():
    """Phase 13 補強：OllamaResponse 解 prompt_eval_count + eval_count"""
    from services.ollama_service import OllamaService

    svc = OllamaService()
    fake_resp = MagicMock(status_code=200)
    fake_resp.json.return_value = {
        'response': 'hello',
        'prompt_eval_count': 250,
        'eval_count': 80,
        'total_duration': 1500000000,  # 1.5s in nanoseconds
    }

    with patch('services.ollama_service.resolve_ollama_host', return_value='http://x:11434'), \
         patch('services.ollama_service.requests.post', return_value=fake_resp):
        resp = svc.generate('test')

    assert resp.success is True
    assert resp.input_tokens == 250
    assert resp.output_tokens == 80
    assert resp.total_duration == 1.5  # 轉換為秒


# ═══════════════════════════════════════════════════════════════════════════
# T3: generate_embedding 三主機 retry（hotfix 6572d52）
# ═══════════════════════════════════════════════════════════════════════════

def test_embedding_retries_on_first_host_timeout():
    """embed 第一台 timeout → 第二台成功"""
    import requests
    from services.ollama_service import OllamaService

    svc = OllamaService()
    fake_ok = MagicMock(status_code=200)
    fake_ok.json.return_value = {'embeddings': [[0.1, 0.2, 0.3]]}

    hosts = ['http://h1:11434', 'http://h2:11434']
    call_seq = [requests.Timeout('h1'), fake_ok]

    with patch('services.ollama_service.resolve_ollama_host', side_effect=hosts), \
         patch.dict('os.environ', {}, clear=False), \
         patch('services.ollama_service.requests.post', side_effect=call_seq) as mock_post:
        # 確保不走 EMBEDDING_HOST env
        import os
        os.environ.pop('EMBEDDING_HOST', None)
        vec = svc.generate_embedding('test text')

    assert vec == [0.1, 0.2, 0.3]
    assert mock_post.call_count == 2  # 第二台成功


def test_embedding_explicit_host_no_retry():
    """caller 顯式 host=... → 不 retry，失敗即回 []"""
    import requests
    from services.ollama_service import OllamaService

    svc = OllamaService()

    with patch('services.ollama_service.requests.post',
               side_effect=requests.Timeout('explicit host fail')) as mock_post:
        vec = svc.generate_embedding('test', host='http://explicit:11434')

    assert vec == []
    # 顯式 host 凍結不 retry → 嘗試一次（/api/embed），可能再試 /api/embeddings legacy
    # 但 retry 鏈不啟動（沒有 for-loop 迭代不同主機）
    # 我們驗：post 呼叫次數 ≤ 2（最多主路徑+legacy 各一次，不會 retry 不同主機）
    assert mock_post.call_count <= 2


def test_embedding_all_three_hosts_fail_returns_empty():
    """embed 三主機都失敗 → 回 []"""
    import requests
    from services.ollama_service import OllamaService

    svc = OllamaService()
    hosts = ['http://h1:11434', 'http://h2:11434', 'http://h3:11434']

    with patch('services.ollama_service.resolve_ollama_host', side_effect=hosts), \
         patch.dict('os.environ', {}, clear=False), \
         patch('services.ollama_service.requests.post',
               side_effect=requests.Timeout('all fail')) as mock_post:
        import os
        os.environ.pop('EMBEDDING_HOST', None)
        vec = svc.generate_embedding('test')

    assert vec == []
    # 三主機 retry，每次主路徑+legacy = 6 次（但 legacy 也是 timeout）
    # 實際看 _embed_one 邏輯：timeout 的 except 直接 mark_unhealthy 不試 legacy
    # 所以是 3 次（主路徑 timeout × 3 主機）
    assert mock_post.call_count == 3


# ═══════════════════════════════════════════════════════════════════════════
# T4: mark_unhealthy 觸發 cache 失效（驗 self.host 取新主機）
# ═══════════════════════════════════════════════════════════════════════════

def test_mark_unhealthy_invalidates_cache_for_next_host():
    """generate 失敗 mark_unhealthy → 下次 self.host 走 resolve 取新主機"""
    import services.ollama_service as oss
    from services.ollama_service import OllamaService

    svc = OllamaService()

    # 先 cache 一個主機
    oss._resolved_host_cache['host'] = 'http://primary:11434'
    oss._resolved_host_cache['ts'] = __import__('time').time()

    # mark_unhealthy 應清空 cache
    oss.mark_unhealthy('http://primary:11434')

    assert oss._resolved_host_cache['host'] is None