"""
Pydantic response models for the Hadith Scholar API.

v2.0 changes:
  - All fields that Neo4j/PG can return as null are now Optional with defaults.
  - Added PaginationMeta / PaginatedResponse for paginated list endpoints.
  - All existing model_config / json_schema_extra examples preserved.
"""
from pydantic import BaseModel, Field
from typing import Optional
from datetime import datetime


# ── Pagination (NEW in v2.0) ───────────────────────────────────────────────

class PaginationMeta(BaseModel):
    total: int = Field(description="Total matching items")
    page: int = Field(description="Current page (1-indexed)")
    per_page: int = Field(description="Items per page")
    pages: int = Field(description="Total pages")

    model_config = {
        "json_schema_extra": {
            "examples": [{"total": 6986, "page": 1, "per_page": 20, "pages": 350}]
        }
    }


class PaginatedResponse(BaseModel):
    meta: PaginationMeta
    data: list


# ── Hadith ─────────────────────────────────────────────────────────────────

class HadithSummary(BaseModel):
    id: str = Field(description="Unique hadith UUID")
    collection: Optional[str] = Field(None, description="Collection name in English")
    hadith_number: Optional[int] = Field(None, description="Hadith number within collection")
    grade: Optional[str] = Field(None, description="Grading: Sahih, Hasan, Da'if, etc.")
    arabic_text: Optional[str] = Field(None, description="Arabic text (truncated in lists)")
    sanad_text: Optional[str] = Field(None, description="Sanad (chain) text only")
    matn_text: Optional[str] = Field(None, description="Matn (body) text only")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "id": "dcf8df41-3185-4e20-a9af-db3696a48c79",
                "collection": "Sahih Bukhari",
                "hadith_number": 1,
                "grade": "Sahih",
                "arabic_text": "حَدَّثَنَا الْحُمَيْدِيُّ عَبْدُ اللَّهِ بْنُ الزُّبَيْرِ...",
                "sanad_text": "حَدَّثَنَا الْحُمَيْدِيُّ...",
                "matn_text": "إِنَّمَا الأَعْمَالُ بِالنِّيَّاتِ...",
            }]
        }
    }


class TopicTag(BaseModel):
    topic_arabic: str = Field("", description="Topic name in Arabic")
    topic_english: str = Field("", description="Topic name in English")
    category: str = Field("", description="Topic category (فقه, عقيدة, سيرة, etc.)")


class NarratorInChain(BaseModel):
    order: Optional[int] = Field(None, description="Position in chain (1 = compiler-end)")
    name_arabic: str = Field(description="Narrator Arabic name")
    name_transliterated: str = Field("", description="Latin transliteration")
    entity_type: str = Field("", description="PERSON, KUNYA, NISBA, TITLE")
    transmission_verb: Optional[str] = Field(None, description="حدثنا, أخبرنا, عن, سمعت, etc.")
    generation: Optional[str] = Field(None, description="صحابي, تابعي, etc.")
    reliability_grade: Optional[str] = Field(None, description="ثقة, صدوق, ضعيف, etc.")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "order": 1,
                "name_arabic": "الْحُمَيْدِيُّ",
                "name_transliterated": "al-Humaydi",
                "entity_type": "NISBA",
                "transmission_verb": "حَدَّثَنَا",
                "generation": "تابع التابعين",
                "reliability_grade": "ثقة",
            }]
        }
    }


class HadithDetail(BaseModel):
    id: str = Field(description="Unique hadith UUID")
    collection: Optional[str] = Field(None, description="Collection name")
    hadith_number: Optional[int] = Field(None, description="Hadith number")
    book_number: Optional[int] = Field(None, description="Book number within collection")
    grade: Optional[str] = Field(None, description="Grading")
    arabic_text: Optional[str] = Field(None, description="Full Arabic text")
    english_text: Optional[str] = Field(None, description="English translation")
    urdu_text: Optional[str] = Field(None, description="Urdu translation")
    sanad_text: Optional[str] = Field(None, description="Sanad (chain) text only")
    matn_text: Optional[str] = Field(None, description="Matn (body) text only")
    narrator_chain: list[NarratorInChain] = Field(default_factory=list, description="Ordered narrator chain from Neo4j graph")
    topics: list[TopicTag] = Field(default_factory=list, description="Topic tags for searchability")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "id": "dcf8df41-3185-4e20-a9af-db3696a48c79",
                "collection": "Sahih Bukhari",
                "hadith_number": 1,
                "grade": "Sahih",
                "arabic_text": "حَدَّثَنَا الْحُمَيْدِيُّ عَبْدُ اللَّهِ بْنُ الزُّبَيْرِ...",
                "sanad_text": "حَدَّثَنَا الْحُمَيْدِيُّ...",
                "matn_text": "إِنَّمَا الأَعْمَالُ بِالنِّيَّاتِ...",
                "narrator_chain": [
                    {"order": 1, "name_arabic": "الْحُمَيْدِيُّ", "name_transliterated": "al-Humaydi", "entity_type": "NISBA", "transmission_verb": "حَدَّثَنَا"},
                    {"order": 2, "name_arabic": "سُفْيَانُ", "name_transliterated": "Sufyan", "entity_type": "PERSON", "transmission_verb": "حَدَّثَنَا"},
                ],
                "topics": [
                    {"topic_arabic": "النية", "topic_english": "Intention", "category": "فقه"},
                ]
            }]
        }
    }


# ── Narrator ───────────────────────────────────────────────────────────────

class NarratorSummary(BaseModel):
    name_arabic: str = Field(description="Primary Arabic name")
    name_transliterated: str = Field("", description="Latin transliteration")
    entity_type: str = Field("", description="PERSON, KUNYA, NISBA, TITLE")
    generation: Optional[str] = Field(None, description="طبقة: صحابي، تابعي، تابع التابعين")
    reliability_grade: Optional[str] = Field(None, description="جرح وتعديل grade: ثقة، صدوق، ضعيف")
    hadith_count: int = Field(0, description="Number of hadiths this narrator appears in")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "name_arabic": "أَبُو هُرَيْرَةَ",
                "name_transliterated": "Abu Hurayrah",
                "entity_type": "KUNYA",
                "generation": "صحابي",
                "reliability_grade": "ثقة",
                "hadith_count": 5374
            }]
        }
    }


class NameForm(BaseModel):
    """Alternative name forms for a narrator (kunya, nisba, laqab, etc.)."""
    name: str = Field(description="Alternative name form")
    type: str = Field(description="Name type: PERSON, KUNYA, NISBA, TITLE")


class FamilyInfo(BaseModel):
    father: Optional[str] = None
    mother: Optional[str] = None
    spouse: Optional[str] = None
    children: list[str] = Field(default_factory=list)


class PlaceRelation(BaseModel):
    place: str = Field(description="Place name in Arabic")
    relation: str = Field(description="BORN_IN, LIVED_IN, DIED_IN, or TRAVELED_TO")

    model_config = {
        "json_schema_extra": {
            "examples": [{"place": "المدينة", "relation": "LIVED_IN"}]
        }
    }


class NarratorProfile(BaseModel):
    """Complete narrator profile — the mobile app profile page."""
    name_arabic: str = Field(description="Primary Arabic name")
    name_transliterated: str = Field("", description="Latin transliteration")
    entity_type: str = Field("", description="PERSON, KUNYA, NISBA, TITLE")
    full_nasab: Optional[str] = Field(None, description="Full lineage: فلان بن فلان بن فلان")
    kunya: Optional[str] = Field(None, description="أبو/أم name (e.g. أبو هريرة)")
    nisba: Optional[str] = Field(None, description="Attributional name (e.g. البخاري، المدني، الزهري)")
    laqab: Optional[str] = Field(None, description="Title or epithet (e.g. أمير المؤمنين في الحديث)")
    generation: Optional[str] = Field(None, description="طبقة: صحابي، تابعي، تابع التابعين، أتباع تابع التابعين")
    reliability_grade: Optional[str] = Field(None, description="جرح وتعديل: ثقة، ثقة حافظ، صدوق، ضعيف، متروك")
    reliability_detail: Optional[str] = Field(None, description="Extended grading explanation from scholars")
    birth_year_hijri: Optional[int] = Field(None, description="Birth year (Hijri calendar)")
    death_year_hijri: Optional[int] = Field(None, description="Death year (Hijri calendar)")
    birth_year_ce: Optional[int] = Field(None, description="Birth year (CE)")
    death_year_ce: Optional[int] = Field(None, description="Death year (CE)")
    biography_summary_arabic: Optional[str] = Field(None, description="2-3 sentence biography in Arabic")
    biography_summary_english: Optional[str] = Field(None, description="2-3 sentence biography in English")
    total_hadiths_narrated_approx: Optional[int] = Field(None, description="Approximate total hadiths narrated across all collections")
    hadith_count: int = Field(0, description="Hadiths in current database")
    hadiths: list[HadithSummary] = Field(default_factory=list, description="Sample hadiths narrated (max 50)")
    teachers: list[NarratorSummary] = Field(default_factory=list, description="Known teachers / شيوخ")
    students: list[NarratorSummary] = Field(default_factory=list, description="Known students / تلاميذ")
    name_forms: list[NameForm] = Field(default_factory=list, description="Alternative name forms")
    family: Optional[FamilyInfo] = Field(None, description="Family info if known")
    places: list[PlaceRelation] = Field(default_factory=list, description="Associated places (born, lived, died, traveled)")
    tribes: list[str] = Field(default_factory=list, description="Tribal affiliations (e.g. قريش، دوس، الأنصار)")
    bio_verified: bool = Field(False, description="Whether biography has been manually verified against classical sources")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "name_arabic": "أَبُو هُرَيْرَةَ",
                "name_transliterated": "Abu Hurayrah",
                "entity_type": "KUNYA",
                "full_nasab": "عبد الرحمن بن صخر الدوسي",
                "kunya": "أبو هريرة",
                "nisba": "الدوسي",
                "laqab": None,
                "generation": "صحابي",
                "reliability_grade": "ثقة",
                "reliability_detail": "صحابي جليل، أكثر الصحابة رواية للحديث",
                "birth_year_hijri": None,
                "death_year_hijri": 57,
                "birth_year_ce": None,
                "death_year_ce": 676,
                "biography_summary_arabic": "أبو هريرة الدوسي، صحابي جليل، أكثر الصحابة رواية للحديث النبوي. أسلم عام خيبر ولازم النبي ﷺ.",
                "biography_summary_english": "Abu Hurayrah al-Dawsi, a prominent Companion and the most prolific narrator of hadith.",
                "total_hadiths_narrated_approx": 5374,
                "hadith_count": 142,
                "teachers": [{"name_arabic": "النبي ﷺ", "name_transliterated": "Prophet Muhammad", "entity_type": "TITLE", "generation": "نبي", "reliability_grade": None, "hadith_count": 0}],
                "students": [{"name_arabic": "الزهري", "name_transliterated": "al-Zuhri", "entity_type": "NISBA", "generation": "تابعي", "reliability_grade": "ثقة", "hadith_count": 0}],
                "places": [{"place": "المدينة", "relation": "LIVED_IN"}],
                "tribes": ["دوس"],
                "bio_verified": False,
            }]
        }
    }


# ── Isnad Chain (D3-ready) ─────────────────────────────────────────────────

class IsnadNode(BaseModel):
    name_arabic: str = Field(description="Narrator Arabic name")
    name_transliterated: str = Field("", description="Latin transliteration")
    entity_type: str = Field("", description="PERSON, KUNYA, NISBA, TITLE")
    generation: Optional[str] = Field(None, description="صحابي, تابعي, etc.")
    reliability_grade: Optional[str] = Field(None, description="ثقة, صدوق, ضعيف, etc.")


class IsnadLink(BaseModel):
    source: str = Field(description="name_arabic of narrator who heard")
    target: str = Field(description="name_arabic of narrator who transmitted")
    transmission_verb: Optional[str] = Field(None, description="حدثنا, عن, أخبرنا, etc.")


class IsnadChain(BaseModel):
    hadith_id: str = Field(description="Hadith UUID")
    collection: Optional[str] = Field(None, description="Collection name")
    hadith_number: Optional[int] = Field(None, description="Hadith number")
    nodes: list[IsnadNode] = Field(default_factory=list, description="Narrators in the chain")
    links: list[IsnadLink] = Field(default_factory=list, description="Directed edges: source heard from target")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "hadith_id": "dcf8df41-3185-4e20-a9af-db3696a48c79",
                "collection": "Sahih Bukhari",
                "hadith_number": 1,
                "nodes": [
                    {"name_arabic": "الْحُمَيْدِيُّ", "name_transliterated": "al-Humaydi", "entity_type": "NISBA", "generation": "تابع التابعين", "reliability_grade": "ثقة"},
                    {"name_arabic": "سُفْيَانُ بْنُ عُيَيْنَةَ", "name_transliterated": "Sufyan ibn Uyaynah", "entity_type": "PERSON", "generation": "تابع التابعين", "reliability_grade": "ثقة"},
                    {"name_arabic": "يَحْيَى بْنُ سَعِيدٍ", "name_transliterated": "Yahya ibn Sa'id al-Ansari", "entity_type": "PERSON", "generation": "تابعي", "reliability_grade": "ثقة"},
                    {"name_arabic": "عُمَرُ بْنُ الْخَطَّابِ", "name_transliterated": "Umar ibn al-Khattab", "entity_type": "PERSON", "generation": "صحابي", "reliability_grade": "ثقة"},
                ],
                "links": [
                    {"source": "الْحُمَيْدِيُّ", "target": "سُفْيَانُ بْنُ عُيَيْنَةَ", "transmission_verb": "حَدَّثَنَا"},
                    {"source": "سُفْيَانُ بْنُ عُيَيْنَةَ", "target": "يَحْيَى بْنُ سَعِيدٍ", "transmission_verb": "حَدَّثَنَا"},
                    {"source": "يَحْيَى بْنُ سَعِيدٍ", "target": "عُمَرُ بْنُ الْخَطَّابِ", "transmission_verb": "عن"},
                ]
            }]
        }
    }


# ── Relationships / Who Met Who ────────────────────────────────────────────

class NarratorInteraction(BaseModel):
    narrator_a: str = Field(description="First narrator Arabic name")
    narrator_a_transliterated: str = Field("", description="First narrator transliteration")
    narrator_b: str = Field(description="Second narrator Arabic name")
    narrator_b_transliterated: str = Field("", description="Second narrator transliteration")
    relationship_type: str = Field("", description="NARRATED_FROM, TEACHER_OF, HEARD_BY, STUDENT_OF")
    shared_hadith_count: int = Field(0, description="Number of hadiths connecting them")
    hadith_ids: list[str] = Field(default_factory=list, description="IDs of shared hadiths (max 20)")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "narrator_a": "الزهري",
                "narrator_a_transliterated": "al-Zuhri",
                "narrator_b": "أنس بن مالك",
                "narrator_b_transliterated": "Anas ibn Malik",
                "relationship_type": "NARRATED_FROM",
                "shared_hadith_count": 23,
                "hadith_ids": ["abc-123", "def-456"]
            }]
        }
    }


class NarratorConnection(BaseModel):
    narrator: str = Field(description="Connected narrator Arabic name")
    narrator_transliterated: str = Field("", description="Transliteration")
    connection_type: str = Field(description="Relationship type")
    direction: str = Field(description="'incoming' (they → this) or 'outgoing' (this → them)")


class NarratorNetwork(BaseModel):
    center: NarratorSummary
    connections: list[NarratorConnection] = Field(default_factory=list)
    total_connections: int = 0


class PathNode(BaseModel):
    name_arabic: str
    name_transliterated: str = ""
    generation: Optional[str] = None


class WhoMetWhoResult(BaseModel):
    narrator_a: str
    narrator_b: str
    path: list[PathNode] = Field(default_factory=list)
    path_length: Optional[int] = None
    relationship_types: list[str] = Field(default_factory=list)


# ── Search ─────────────────────────────────────────────────────────────────

class SemanticSearchResult(BaseModel):
    hadith: HadithSummary = Field(description="Matching hadith")
    score: float = Field(description="Cosine similarity score (0-1, higher = more relevant)")
    collection: str = Field("", description="Collection name")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "hadith": {
                    "id": "abc-123",
                    "collection": "Sahih Bukhari",
                    "hadith_number": 1,
                    "grade": "Sahih",
                    "arabic_text": "إِنَّمَا الأَعْمَالُ بِالنِّيَّاتِ..."
                },
                "score": 0.9234,
                "collection": "Sahih Bukhari"
            }]
        }
    }


class FullTextSearchResult(BaseModel):
    hadith: HadithSummary = Field(description="Matching hadith")
    score: float = Field(description="Elasticsearch relevance score")
    highlights: list[str] = Field(default_factory=list, description="Text fragments with <em> highlighted matches")

    model_config = {
        "json_schema_extra": {
            "examples": [{
                "hadith": {
                    "id": "abc-123",
                    "collection": "Sahih Muslim",
                    "hadith_number": 1599,
                    "grade": "Sahih",
                    "arabic_text": "..."
                },
                "score": 12.45,
                "highlights": ["...عن <em>الصلاة</em> في المسجد..."]
            }]
        }
    }


class CombinedSearchResult(BaseModel):
    hadith: HadithSummary
    semantic_score: Optional[float] = None
    fulltext_score: Optional[float] = None
    combined_score: float = 0.0
    source: str = Field(description="semantic, fulltext, or both")


# ── Stats ──────────────────────────────────────────────────────────────────

class SystemStats(BaseModel):
    hadiths_pg: Optional[int] = None
    narrators_neo4j: Optional[int] = None
    places_neo4j: Optional[int] = None
    tribes_neo4j: Optional[int] = None
    relationships_neo4j: Optional[int] = None
    embeddings_qdrant: Optional[int] = None
    documents_es: Optional[int] = None