"""
GovBridge India — Backend Test Suite
Comprehensive pytest tests for CI/CD pipeline.
Tests pure business logic without external dependencies.
"""
import pytest
from unittest.mock import patch, MagicMock, AsyncMock
from datetime import date, timedelta


# ============================================================
# 1. CONFIG MODULE TESTS
# ============================================================

class TestConfig:
    """Test pydantic-settings configuration module."""

    def test_settings_loads_with_defaults(self):
        """Settings should initialize with empty defaults when no env vars set."""
        with patch.dict("os.environ", {}, clear=True):
            from pydantic_settings import BaseSettings, SettingsConfigDict
            from pydantic import Field

            class TestSettings(BaseSettings):
                SUPABASE_URL: str = Field(default="")
                SUPABASE_KEY: str = Field(default="")
                model_config = SettingsConfigDict(extra="ignore")

            s = TestSettings()
            assert s.SUPABASE_URL == ""
            assert s.SUPABASE_KEY == ""

    def test_settings_reads_env_vars(self):
        """Settings should read from environment variables."""
        with patch.dict("os.environ", {
            "SUPABASE_URL": "https://test.supabase.co",
            "SUPABASE_KEY": "test-key-123"
        }):
            from pydantic_settings import BaseSettings, SettingsConfigDict
            from pydantic import Field

            class TestSettings(BaseSettings):
                SUPABASE_URL: str = Field(default="")
                SUPABASE_KEY: str = Field(default="")
                model_config = SettingsConfigDict(extra="ignore")

            s = TestSettings()
            assert s.SUPABASE_URL == "https://test.supabase.co"
            assert s.SUPABASE_KEY == "test-key-123"


# ============================================================
# 2. PYDANTIC MODEL VALIDATION TESTS
# ============================================================

class TestSearchQueryValidation:
    """Test SearchQuery Pydantic model from api.py."""

    def test_valid_query(self):
        """Valid search query should pass validation."""
        from pydantic import BaseModel, Field, field_validator
        import re

        class SearchQuery(BaseModel):
            question: str = Field(..., min_length=3, max_length=500)
            language: str = Field(default="english")

            @field_validator('language')
            @classmethod
            def validate_language(cls, v):
                valid = ["english", "hindi", "tamil", "bengali", "telugu",
                         "marathi", "gujarati", "kannada", "malayalam", "punjabi"]
                if v.lower() not in valid:
                    return "english"
                return v.lower()

            @field_validator('question')
            @classmethod
            def clean_input(cls, v):
                v = re.sub(r'<[^>]+>', '', v)
                v = re.sub(r'\s+', ' ', v).strip()
                if not v:
                    raise ValueError('Question is empty after cleaning')
                return v

        q = SearchQuery(question="What is PM Kisan?", language="hindi")
        assert q.question == "What is PM Kisan?"
        assert q.language == "hindi"

    def test_html_stripped_from_question(self):
        """HTML tags should be stripped from question input."""
        from pydantic import BaseModel, Field, field_validator
        import re

        class SearchQuery(BaseModel):
            question: str = Field(..., min_length=3, max_length=500)
            language: str = Field(default="english")

            @field_validator('question')
            @classmethod
            def clean_input(cls, v):
                v = re.sub(r'<[^>]+>', '', v)
                v = re.sub(r'\s+', ' ', v).strip()
                if not v:
                    raise ValueError('Question is empty after cleaning')
                return v

        q = SearchQuery(question="<script>alert('xss')</script>What is PM Kisan?")
        assert "<script>" not in q.question
        assert "alert" in q.question  # text content preserved

    def test_invalid_language_defaults_to_english(self):
        """Unknown language should default to english."""
        from pydantic import BaseModel, Field, field_validator

        class SearchQuery(BaseModel):
            question: str = Field(..., min_length=3, max_length=500)
            language: str = Field(default="english")

            @field_validator('language')
            @classmethod
            def validate_language(cls, v):
                valid = ["english", "hindi", "tamil", "bengali", "telugu",
                         "marathi", "gujarati", "kannada", "malayalam", "punjabi"]
                if v.lower() not in valid:
                    return "english"
                return v.lower()

        q = SearchQuery(question="Test query", language="french")
        assert q.language == "english"

    def test_question_too_short_fails(self):
        """Question shorter than 3 chars should fail validation."""
        from pydantic import BaseModel, Field, ValidationError

        class SearchQuery(BaseModel):
            question: str = Field(..., min_length=3, max_length=500)

        with pytest.raises(ValidationError):
            SearchQuery(question="ab")

    def test_whitespace_only_question_fails(self):
        """Whitespace-only question should fail after cleaning."""
        from pydantic import BaseModel, Field, field_validator, ValidationError
        import re

        class SearchQuery(BaseModel):
            question: str = Field(..., min_length=3, max_length=500)

            @field_validator('question')
            @classmethod
            def clean_input(cls, v):
                v = re.sub(r'<[^>]+>', '', v)
                v = re.sub(r'\s+', ' ', v).strip()
                if not v:
                    raise ValueError('Question is empty after cleaning')
                return v

        with pytest.raises(ValidationError):
            SearchQuery(question="   ")


class TestIngestRequestValidation:
    """Test IngestRequest Pydantic model."""

    def test_valid_ingest_request(self):
        """Valid ingest request should pass."""
        from pydantic import BaseModel
        from typing import Optional

        class IngestRequest(BaseModel):
            title: str
            text: str
            ministry: Optional[str] = None
            doc_type: Optional[str] = "scheme"

        req = IngestRequest(title="PM Kisan", text="Financial benefit scheme")
        assert req.title == "PM Kisan"
        assert req.doc_type == "scheme"
        assert req.ministry is None

    def test_ingest_request_with_all_fields(self):
        """Ingest request with all optional fields."""
        from pydantic import BaseModel
        from typing import Optional

        class IngestRequest(BaseModel):
            title: str
            text: str
            ministry: Optional[str] = None
            state: Optional[str] = None
            source_url: Optional[str] = None
            doc_type: Optional[str] = "scheme"

        req = IngestRequest(
            title="PM Kisan",
            text="Scheme details",
            ministry="Agriculture",
            state="Rajasthan",
            source_url="https://pmkisan.gov.in",
            doc_type="notification"
        )
        assert req.ministry == "Agriculture"
        assert req.state == "Rajasthan"
        assert req.doc_type == "notification"


class TestEligibilityRequestValidation:
    """Test EligibilityRequest Pydantic model."""

    def test_valid_eligibility_request(self):
        """Valid eligibility check request."""
        from pydantic import BaseModel, Field

        class EligibilityRequest(BaseModel):
            annual_income: float = Field(..., ge=0)
            age: int = Field(..., ge=0, le=120)
            is_farmer: bool = False
            state: str = ""
            caste_category: str = "General"

        req = EligibilityRequest(annual_income=100000, age=30, is_farmer=True, state="Rajasthan")
        assert req.annual_income == 100000
        assert req.is_farmer is True
        assert req.caste_category == "General"

    def test_negative_income_fails(self):
        """Negative income should fail validation."""
        from pydantic import BaseModel, Field, ValidationError

        class EligibilityRequest(BaseModel):
            annual_income: float = Field(..., ge=0)
            age: int = Field(..., ge=0, le=120)

        with pytest.raises(ValidationError):
            EligibilityRequest(annual_income=-5000, age=25)

    def test_age_over_120_fails(self):
        """Age over 120 should fail validation."""
        from pydantic import BaseModel, Field, ValidationError

        class EligibilityRequest(BaseModel):
            annual_income: float = Field(..., ge=0)
            age: int = Field(..., ge=0, le=120)

        with pytest.raises(ValidationError):
            EligibilityRequest(annual_income=50000, age=150)


# ============================================================
# 3. CHUNK_TEXT BUSINESS LOGIC TESTS
# ============================================================

class TestChunkText:
    """Test the text chunking function — pure business logic, no dependencies."""

    @staticmethod
    def chunk_text(text: str, chunk_size: int = 500, overlap: int = 50) -> list[str]:
        """Mirror of api.py chunk_text for isolated testing."""
        paragraphs = [p.strip() for p in text.split('\n\n') if p.strip()]
        chunks = []
        current = ""
        for para in paragraphs:
            if len(current) + len(para) < chunk_size:
                current += " " + para
            else:
                if current.strip():
                    chunks.append(current.strip())
                current = para
        if current.strip():
            chunks.append(current.strip())
        if len(chunks) <= 1:
            return chunks
        overlapped = [chunks[0]]
        for i in range(1, len(chunks)):
            tail = chunks[i-1][-overlap:] if len(chunks[i-1]) > overlap else chunks[i-1]
            overlapped.append(tail + " " + chunks[i])
        return overlapped

    def test_empty_text(self):
        """Empty text should return empty list."""
        assert self.chunk_text("") == []

    def test_short_text_single_chunk(self):
        """Text shorter than chunk_size should return single chunk."""
        result = self.chunk_text("This is a short text about PM Kisan scheme.")
        assert len(result) == 1
        assert "PM Kisan" in result[0]

    def test_long_text_multiple_chunks(self):
        """Long text should be split into multiple chunks."""
        paragraphs = ["Paragraph " + str(i) + " " + ("x" * 300) for i in range(5)]
        text = "\n\n".join(paragraphs)
        result = self.chunk_text(text, chunk_size=400)
        assert len(result) > 1

    def test_overlap_present(self):
        """Chunks after the first should contain overlap from previous chunk."""
        p1 = "A" * 300
        p2 = "B" * 300
        text = p1 + "\n\n" + p2
        result = self.chunk_text(text, chunk_size=350, overlap=50)
        if len(result) > 1:
            # Second chunk should start with tail of first chunk
            assert result[1].startswith(result[0][-50:])

    def test_whitespace_only_paragraphs_ignored(self):
        """Paragraphs with only whitespace should be filtered out."""
        text = "Real content\n\n   \n\n  \n\nMore content"
        result = self.chunk_text(text)
        assert len(result) == 1  # Both fit in one chunk
        assert "Real content" in result[0]
        assert "More content" in result[0]


# ============================================================
# 4. WHATSAPP EXPIRY ALERTS TESTS
# ============================================================

class TestExpiryAlerts:
    """Test WhatsApp expiry alert payload generation."""

    @staticmethod
    def generate_alert_payload(scheme: dict, phone_number: str) -> dict:
        """Mirror of expiry_alerts.py generate_alert_payload for isolated testing."""
        title = scheme.get("title", "Government Scheme")
        deadline = scheme.get("deadline_date", "Unknown Date")
        url = scheme.get("source_url", "https://myscheme.gov.in")

        return {
            "messaging_product": "whatsapp",
            "to": phone_number,
            "type": "template",
            "template": {
                "name": "scheme_expiry_alert",
                "language": {"code": "en_US"},
                "components": [
                    {
                        "type": "body",
                        "parameters": [
                            {"type": "text", "text": title},
                            {"type": "text", "text": deadline}
                        ]
                    },
                    {
                        "type": "button",
                        "sub_type": "url",
                        "index": "0",
                        "parameters": [
                            {"type": "text", "text": url}
                        ]
                    }
                ]
            }
        }

    def test_payload_structure(self):
        """Alert payload should have correct WhatsApp API structure."""
        scheme = {
            "title": "PM Kisan",
            "deadline_date": "2026-06-15",
            "source_url": "https://pmkisan.gov.in"
        }
        payload = self.generate_alert_payload(scheme, "+919876543210")

        assert payload["messaging_product"] == "whatsapp"
        assert payload["to"] == "+919876543210"
        assert payload["type"] == "template"
        assert payload["template"]["name"] == "scheme_expiry_alert"
        assert payload["template"]["language"]["code"] == "en_US"

    def test_payload_contains_scheme_title(self):
        """Payload body should contain the scheme title."""
        scheme = {"title": "PM Awas Yojana", "deadline_date": "2026-07-01"}
        payload = self.generate_alert_payload(scheme, "+91111")
        body_params = payload["template"]["components"][0]["parameters"]
        assert body_params[0]["text"] == "PM Awas Yojana"

    def test_payload_contains_deadline(self):
        """Payload body should contain the deadline date."""
        scheme = {"title": "Test", "deadline_date": "2026-12-31"}
        payload = self.generate_alert_payload(scheme, "+91222")
        body_params = payload["template"]["components"][0]["parameters"]
        assert body_params[1]["text"] == "2026-12-31"

    def test_payload_default_url(self):
        """Missing source_url should default to myscheme.gov.in."""
        scheme = {"title": "Test"}
        payload = self.generate_alert_payload(scheme, "+91333")
        button_params = payload["template"]["components"][1]["parameters"]
        assert button_params[0]["text"] == "https://myscheme.gov.in"

    def test_payload_default_title(self):
        """Missing title should default to 'Government Scheme'."""
        scheme = {}
        payload = self.generate_alert_payload(scheme, "+91444")
        body_params = payload["template"]["components"][0]["parameters"]
        assert body_params[0]["text"] == "Government Scheme"


# ============================================================
# 5. ELIGIBILITY ENGINE TESTS (OpenFisca)
# ============================================================

class TestEligibilityEngine:
    """Test eligibility engine deterministic logic."""

    @pytest.fixture
    def engine(self):
        """Import eligibility engine — requires openfisca-core."""
        try:
            from eligibility.engine import check_eligibility
            return check_eligibility
        except ImportError:
            pytest.skip("openfisca-core not installed")

    def test_farmer_eligible_for_pm_kisan(self, engine):
        """A farmer with low income should be eligible for PM Kisan."""
        profile = {
            "annual_income": 100000,
            "age": 35,
            "is_farmer": True,
            "state": "Rajasthan",
            "caste_category": "General"
        }
        results = engine(profile)
        assert "eligible_pm_kisan" in results
        assert results["eligible_pm_kisan"] is True

    def test_non_farmer_ineligible_for_pm_kisan(self, engine):
        """A non-farmer should NOT be eligible for PM Kisan."""
        profile = {
            "annual_income": 100000,
            "age": 35,
            "is_farmer": False,
            "state": "Rajasthan",
            "caste_category": "General"
        }
        results = engine(profile)
        assert results["eligible_pm_kisan"] is False

    def test_returns_all_eligibility_variables(self, engine):
        """Engine should return results for all 10 scheme variables."""
        profile = {
            "annual_income": 200000,
            "age": 40,
            "is_farmer": True,
            "state": "Rajasthan",
            "caste_category": "SC"
        }
        results = engine(profile)
        expected_keys = [
            "eligible_pm_kisan",
            "eligible_chiranjeevi",
            "eligible_palanhar",
            "eligible_ekal_nari",
            "eligible_devnarayan_scholarship",
            "eligible_incentive_to_girls",
            "eligible_widow_bed_scheme",
            "eligible_nirman_shramik_auzaar",
            "eligible_indira_mahila_shakti",
            "eligible_ayushman_arogya"
        ]
        for key in expected_keys:
            assert key in results, f"Missing eligibility variable: {key}"
            assert isinstance(results[key], bool), f"{key} should be boolean"

    def test_high_income_limits_eligibility(self, engine):
        """Very high income should reduce scheme eligibility."""
        profile = {
            "annual_income": 5000000,  # 50 lakh
            "age": 35,
            "is_farmer": False,
            "state": "Maharashtra",
            "caste_category": "General"
        }
        results = engine(profile)
        # At 50 lakh income, most welfare schemes should not apply
        eligible_count = sum(1 for v in results.values() if v)
        assert eligible_count < len(results), "High income should limit some eligibility"


# ============================================================
# 6. BHASHINI LANGUAGE MAP TESTS
# ============================================================

class TestBhashiniLanguageMaps:
    """Test language code mappings are complete and correct."""

    def test_language_codes_mapping(self):
        """LANGUAGE_CODES should map all 10 supported languages + english."""
        LANGUAGE_CODES = {
            "hindi": "hi", "tamil": "ta", "bengali": "bn",
            "telugu": "te", "marathi": "mr", "gujarati": "gu",
            "kannada": "kn", "malayalam": "ml", "punjabi": "pa",
            "odia": "or", "english": "en"
        }
        assert len(LANGUAGE_CODES) == 11
        assert LANGUAGE_CODES["hindi"] == "hi"
        assert LANGUAGE_CODES["english"] == "en"
        assert LANGUAGE_CODES["tamil"] == "ta"

    def test_indictrans_lang_map(self):
        """IndicTrans language map should use BCP47-like codes."""
        INDICTRANS_LANG_MAP = {
            "hindi": "hin_Deva",
            "tamil": "tam_Taml",
            "bengali": "ben_Beng",
            "telugu": "tel_Telu",
            "marathi": "mar_Deva",
            "gujarati": "guj_Gujr",
            "kannada": "kan_Knda",
            "malayalam": "mal_Mlym",
            "punjabi": "pan_Guru",
            "odia": "ory_Orya",
            "english": "eng_Latn"
        }
        assert len(INDICTRANS_LANG_MAP) == 11
        assert INDICTRANS_LANG_MAP["hindi"] == "hin_Deva"
        # Verify all values follow the xxx_Yyyy pattern
        for lang, code in INDICTRANS_LANG_MAP.items():
            assert "_" in code, f"Code for {lang} should contain underscore"
            parts = code.split("_")
            assert len(parts[0]) == 3, f"Script code for {lang} should be 3 chars"
            assert len(parts[1]) == 4, f"Script name for {lang} should be 4 chars"


# ── Sprint 19: OpenFisca Neuro-Symbolic Tests ────────────────────────────

class TestOpenFiscaEngine:
    """Test the deterministic eligibility engine."""
    
    def test_pm_kisan_eligible(self):
        """Farmer with low income should qualify for PM-KISAN."""
        from eligibility.engine import check_eligibility
        profile = {
            "annual_income": 150000,
            "age": 45,
            "is_farmer": True,
            "state": "Rajasthan",
            "caste_category": "General",
        }
        results = check_eligibility(profile)
        assert results["eligible_pm_kisan"] is True
    
    def test_pm_kisan_not_eligible_high_income(self):
        """Non-farmer should NOT qualify for PM-KISAN."""
        from eligibility.engine import check_eligibility
        profile = {
            "annual_income": 500000,
            "age": 30,
            "is_farmer": False,
            "state": "Delhi",
            "caste_category": "General",
        }
        results = check_eligibility(profile)
        assert results["eligible_pm_kisan"] is False
    
    def test_pmjay_eligible_low_income(self):
        """Low income citizen should qualify for PMJAY."""
        from eligibility.engine import check_eligibility
        profile = {
            "annual_income": 300000,
            "age": 35,
            "is_farmer": False,
            "state": "Maharashtra",
            "caste_category": "OBC",
        }
        results = check_eligibility(profile)
        assert results["eligible_pmjay"] is True
    
    def test_pmjay_not_eligible_high_income(self):
        """High income citizen should NOT qualify for PMJAY."""
        from eligibility.engine import check_eligibility
        profile = {
            "annual_income": 800000,
            "age": 35,
            "is_farmer": False,
            "state": "Maharashtra",
            "caste_category": "General",
        }
        results = check_eligibility(profile)
        assert results["eligible_pmjay"] is False
    
    def test_all_variables_present(self):
        """Engine should evaluate all registered variables without crashing."""
        from eligibility.engine import check_eligibility, ELIGIBILITY_VARIABLES
        profile = {
            "annual_income": 200000,
            "age": 30,
            "is_farmer": True,
            "state": "Rajasthan",
            "caste_category": "SC",
            "gender": "Male",
            "is_bpl": True,
            "land_size_hectares": 1.5,
            "is_disabled": False,
            "occupation": "Farmer",
        }
        results = check_eligibility(profile)
        assert len(results) == len(ELIGIBILITY_VARIABLES)
        # All keys should be present
        for var in ELIGIBILITY_VARIABLES:
            assert var in results


class TestNeuroSymbolicBridge:
    """Test the intent classification and parameter extraction."""
    
    def test_missing_field_detection(self):
        """Should detect missing required fields."""
        from neuro_symbolic import detect_missing_fields
        # Empty profile — everything is missing
        missing = detect_missing_fields({})
        assert "annual_income" in missing
        assert "age" in missing
        assert "state" in missing
    
    def test_complete_profile_no_missing(self):
        """Complete profile should have no missing required fields."""
        from neuro_symbolic import detect_missing_fields
        profile = {"annual_income": 200000, "age": 30, "state": "Delhi"}
        missing = detect_missing_fields(profile)
        assert len(missing) == 0