import hashlib
import json
import math
import os
import secrets
from contextlib import asynccontextmanager
from datetime import datetime, timedelta, timezone
from uuid import UUID, uuid4

from botocore.exceptions import ClientError
from fastapi import Depends, FastAPI, HTTPException, Request, Response
from fastapi.responses import JSONResponse
from starlette.middleware.trustedhost import TrustedHostMiddleware
from psycopg.types.json import Jsonb

from . import db
from .adapters import FakeFreight, FakePayment, LocalS3Storage, require_local
from .models import Freight, Move, Pay, QuoteRequest, Review, UploadStart, OperatorLogin
from .pricing import price
from .auth import owner, session_row, new_session, operator, throttle, audit, rate_limit
from .scanning import require_clean

require_local()
storage = LocalS3Storage()
payment = FakePayment()
freight = FakeFreight()
PART_BYTES = int(os.environ.get('UPLOAD_PART_BYTES', '8388608'))
if not 5242880 <= PART_BYTES <= 67108864:
    raise RuntimeError('UPLOAD_PART_BYTES must be between 5 and 64 MiB')
STATES = {'rec': 'Arte recebida', 'tra': 'Arte tratada', 'fil': 'Fila de impressão',
          'imp': 'Imprimindo', 'cor': 'Correção', 'fin': 'Finalizado'}
TRANSITIONS = {'rec': ['tra','cor'], 'tra': ['fil','cor'], 'fil': ['imp','cor'],
               'imp': ['fin','cor'], 'cor': ['rec','tra'], 'fin': []}

@asynccontextmanager
async def lifespan(app):
    with db.connect() as c:
        c.execute('SELECT 1 FROM dtf_local.operator_sessions LIMIT 1')
    storage.health()
    yield

app = FastAPI(title='DTF Local Portal/API', lifespan=lifespan, docs_url=None, redoc_url=None)
app.add_middleware(TrustedHostMiddleware, allowed_hosts=['localhost', '127.0.0.1'])

@app.post('/api/operator/login')
def operator_login(body: OperatorLogin, request: Request, response: Response):
    throttle('operator:'+body.username, request)
    valid_user = secrets.compare_digest(body.username.encode(), os.environ['OPERATOR_USER'].encode())
    valid_password = secrets.compare_digest(body.password.encode(), os.environ['OPERATOR_PASSWORD'].encode())
    if not (valid_user and valid_password):
        audit('operator_login_failed')
        raise HTTPException(401, 'Invalid local operator login')
    token = secrets.token_urlsafe(32)
    with db.connect() as c:
        previous = hashlib.sha256(request.cookies.get('dtf_operator','').encode()).hexdigest()
        c.execute('DELETE FROM dtf_local.operator_sessions WHERE token_hash=%s', (previous,))
        c.execute('INSERT INTO dtf_local.operator_sessions(token_hash,username) VALUES(%s,%s)',
                  (hashlib.sha256(token.encode()).hexdigest(), body.username))
    response.set_cookie('dtf_operator', token, httponly=True, samesite='strict', path='/api/operator', max_age=28800)
    audit('operator_login_success', operator=body.username)
    return {'ok': True}

@app.post('/api/operator/logout')
def operator_logout(request: Request, response: Response):
    with db.connect() as c:
        digest = hashlib.sha256(request.cookies.get('dtf_operator','').encode()).hexdigest()
        c.execute('DELETE FROM dtf_local.operator_sessions WHERE token_hash=%s', (digest,))
    response.delete_cookie('dtf_operator', path='/api/operator', httponly=True, samesite='strict')
    audit('operator_logout')
    return {'ok': True}

@app.middleware('http')
async def safe_headers(request, call_next):
    if request.method not in ('GET','HEAD','OPTIONS'):
        origin = request.headers.get('origin')
        if request.headers.get('sec-fetch-site') == 'cross-site' or (origin and origin != 'http://'+request.headers.get('host','')):
            audit('cross_origin_rejected')
            return JSONResponse({'detail':'Cross-origin request rejected'}, status_code=403)
    response = await call_next(request)
    if response.status_code in (401,403,429) or response.status_code>=500:
        audit('http_security_event', method=request.method, status=response.status_code)
    response.headers['Cache-Control'] = 'no-store'
    response.headers['X-Content-Type-Options'] = 'nosniff'
    response.headers['Referrer-Policy'] = 'no-referrer'
    return response

@app.get('/health')
@app.get('/api/health')
def health():
    try:
        with db.connect() as c:
            c.execute('SELECT 1')
        storage.health()
    except Exception:
        raise HTTPException(503, 'Database or storage unavailable')
    return {'status': 'ok', 'environment': 'local', 'storage': 'minio', 'integrations': 'fake'}

@app.get('/api/session')
def session(request: Request, response: Response):
    try:
        session_id = owner(request)
    except HTTPException:
        rate_limit('guest-sessions', 'local-stack', 120, 900)
        with db.connect() as c:
            session_id = new_session(c, response)
    return {'environment': 'local', 'cart_scope': str(session_id), 'part_bytes': PART_BYTES,
            'max_upload_bytes': int(os.environ.get('MAX_UPLOAD_BYTES', '5368709120'))}

@app.post('/api/freight')
def quote_freight(body: Freight):
    try:
        return freight.quote(body.service, body.postal_code)
    except ValueError as exc:
        raise HTTPException(422, str(exc))

def upload_row(c, upload_id, session_id, lock=False):
    row = c.execute('SELECT * FROM dtf_local.uploads WHERE id=%s AND owner=%s' +
                    (' FOR UPDATE' if lock else ''), (upload_id, session_id)).fetchone()
    if not row:
        raise HTTPException(404, 'Upload not found')
    days = 30 if row['complete'] else 1
    if row['purged_at'] or row['expires_at'] <= datetime.now(timezone.utc) or row['created_at'] < datetime.now(timezone.utc) - timedelta(days=days):
        raise HTTPException(410, 'Upload expired; select the file again')
    return row

@app.post('/api/uploads')
def begin_upload(body: UploadStart, session_id=Depends(owner)):
    if body.size > int(os.environ.get('MAX_UPLOAD_BYTES', '5368709120')):
        raise HTTPException(413, 'File exceeds the local upload limit')
    uid = uuid4()
    key = f'originals/{uid}'
    rate_limit('upload-start', str(session_id), 60, 900)
    with db.connect() as c:
        # Serialize reservations across API processes, including changing guest IDs.
        c.execute('SELECT pg_advisory_xact_lock(804208)')
        usage = c.execute('''SELECT COALESCE(sum(size),0) AS total,
            COALESCE(sum(size) FILTER(WHERE owner=%s),0) AS owned,
            count(*) FILTER(WHERE owner=%s AND NOT complete) AS pending
            FROM dtf_local.uploads WHERE purged_at IS NULL''', (session_id,session_id)).fetchone()
        if (usage['total']+body.size > int(os.environ.get('STORAGE_QUOTA_BYTES','53687091200')) or
            usage['owned']+body.size > int(os.environ.get('OWNER_UPLOAD_QUOTA_BYTES','10737418240')) or
            usage['pending'] >= int(os.environ.get('MAX_PENDING_UPLOADS','10'))):
            audit('upload_quota_rejected')
            raise HTTPException(429, 'Local storage quota or pending upload limit reached')
        multipart = storage.begin(key)
        c.execute('INSERT INTO dtf_local.uploads(id,owner,name,size,object_key,multipart_id) VALUES(%s,%s,%s,%s,%s,%s)',
                  (uid, session_id, body.name, body.size, key, multipart))
    return {'id': uid, 'part_bytes': PART_BYTES}

@app.get('/api/uploads/{uid}')
def upload_status(uid: UUID, session_id=Depends(owner)):
    with db.connect() as c:
        row = upload_row(c, uid, session_id)
    parts = [] if row['complete'] else storage.parts(row['object_key'], row['multipart_id'])
    return {'id': uid, 'complete': row['complete'], 'part_bytes': PART_BYTES,
            'scan_state':row['scan_state'], 'scan_reason':row['scan_reason'],
            'parts': [p['PartNumber'] for p in parts]}

@app.post('/api/uploads/{uid}/parts/{part}')
def part_url(uid: UUID, part: int, session_id=Depends(owner)):
    with db.connect() as c:
        row = upload_row(c, uid, session_id)
    if row['complete'] or not 1 <= part <= math.ceil(row['size'] / PART_BYTES):
        raise HTTPException(409, 'Invalid part or completed upload')
    size = min(PART_BYTES, row['size']-(part-1)*PART_BYTES)
    return {'url': storage.part_url(row['object_key'], row['multipart_id'], part, size)}

@app.post('/api/uploads/{uid}/complete')
def complete_upload(uid: UUID, session_id=Depends(owner)):
    with db.connect() as c:
        row = upload_row(c, uid, session_id, lock=True)
        if row['complete']:
            return {'id': uid, 'complete': True}
        try:
            existing_size = storage.size(row['object_key'])
        except ClientError as exc:
            if exc.response['ResponseMetadata']['HTTPStatusCode'] != 404:
                raise
            existing_size = None
        if existing_size is None:
            parts = storage.parts(row['object_key'], row['multipart_id'])
            expected = math.ceil(row['size'] / PART_BYTES)
            if [p['PartNumber'] for p in parts] != list(range(1, expected+1)) or any(
                p['Size'] != min(PART_BYTES, row['size'] - i*PART_BYTES) for i,p in enumerate(parts)):
                raise HTTPException(409, 'Parts are missing or their sizes do not match')
            storage.complete(row['object_key'], row['multipart_id'], parts)
            existing_size = storage.size(row['object_key'])
        if existing_size != row['size']:
            raise HTTPException(409, 'Stored size differs from declared size')
        c.execute('UPDATE dtf_local.uploads SET complete=true WHERE id=%s', (uid,))
    return {'id': uid, 'complete': True}

@app.post('/api/quotes')
def create_quote(body: QuoteRequest, session_id=Depends(owner)):
    draft = body.model_dump(mode='json', exclude={'request_key'})
    digest = hashlib.sha256(json.dumps(draft, sort_keys=True).encode()).hexdigest()
    try:
        freight.quote(body.freight.service, body.freight.postal_code)
    except ValueError as exc:
        raise HTTPException(422, str(exc))
    with db.connect() as c:
        for item in body.items:
            for uid in item.uploads:
                row = upload_row(c, uid, session_id)
                if not row['complete']:
                    raise HTTPException(409, 'Complete every upload before requesting a quote')
                require_clean(row)
        uid = uuid4()
        c.execute('INSERT INTO dtf_local.quotes(id,owner,request_key,request_hash,draft) VALUES(%s,%s,%s,%s,%s) ON CONFLICT(owner,request_key) DO NOTHING',
                  (uid, session_id, body.request_key, digest, Jsonb(draft)))
        row = c.execute('SELECT * FROM dtf_local.quotes WHERE owner=%s AND request_key=%s', (session_id, body.request_key)).fetchone()
        if row['request_hash'] != digest:
            raise HTTPException(409, 'Request key already used for a different cart')
    return {'id': row['id'], 'status': 'pending_review'}

def quote_view(c, row):
    order = c.execute('SELECT id,number,state FROM dtf_local.orders WHERE quote_id=%s', (row['id'],)).fetchone()
    expired = row['approved_at'] and row['approved_at'] < datetime.now(timezone.utc)-timedelta(hours=24)
    return {'id': row['id'], 'draft': row['draft'], 'approved': row['approved'],
            'status': 'paid' if order else 'expired' if expired else 'approved' if row['approved'] else 'pending_review',
            'order': order}

@app.get('/api/quotes/{uid}')
def get_quote(uid: UUID, session_id=Depends(owner)):
    with db.connect() as c:
        row = c.execute('SELECT * FROM dtf_local.quotes WHERE id=%s AND owner=%s', (uid,session_id)).fetchone()
        if not row:
            raise HTTPException(404, 'Quote not found')
        return quote_view(c, row)

def enqueue(c, event_key, provider, payload):
    c.execute('INSERT INTO dtf_local.outbox(event_key,provider,payload) VALUES(%s,%s,%s) ON CONFLICT(event_key) DO NOTHING',
              (event_key, provider, Jsonb(payload)))

@app.post('/api/orders/dev-paid')
def dev_paid(body: Pay, session_id=Depends(owner)):
    with db.connect() as c:
        row = c.execute('SELECT * FROM dtf_local.quotes WHERE id=%s AND owner=%s FOR UPDATE', (body.quote_id,session_id)).fetchone()
        if not row:
            raise HTTPException(404, 'Quote not found')
        existing = c.execute('SELECT * FROM dtf_local.orders WHERE quote_id=%s', (body.quote_id,)).fetchone()
        if existing:
            return existing
        if not row['approved']:
            raise HTTPException(409, 'An operator must verify length and grade first')
        if row['approved_at'] < datetime.now(timezone.utc)-timedelta(hours=24):
            raise HTTPException(409, 'Quote expired; request a new quote')
        approved = row['approved']
        for item in approved['items']:
            for upload_id in item['uploads']:
                require_clean(upload_row(c, UUID(upload_id), session_id))
        paid = payment.pay(str(body.quote_id), approved['total_cents'])
        result = c.execute('INSERT INTO dtf_local.orders(id,quote_id,owner,snapshot,payment) VALUES(%s,%s,%s,%s,%s) RETURNING *',
            (uuid4(),body.quote_id,session_id,Jsonb(approved),Jsonb(paid))).fetchone()
        for provider in ('tiny','whatsapp'):
            enqueue(c, f"{result['id']}:paid:{provider}", provider,
                    {'order_id': str(result['id']), 'number': result['number'], 'event': 'payment_approved', 'order': approved})
    return result

@app.get('/api/operator/board')
def board(user=Depends(operator)):
    with db.connect() as c:
        orders = c.execute('SELECT * FROM dtf_local.orders ORDER BY created_at').fetchall()
        quotes = c.execute('SELECT q.* FROM dtf_local.quotes q LEFT JOIN dtf_local.orders o ON o.quote_id=q.id WHERE o.id IS NULL ORDER BY q.created_at').fetchall()
        return {'states': STATES, 'transitions': TRANSITIONS, 'orders': orders,
                'quotes': [quote_view(c, q) for q in quotes],
                'events': c.execute('SELECT * FROM dtf_local.outbox ORDER BY id DESC LIMIT 100').fetchall()}

@app.post('/api/operator/quotes/{uid}/approve')
def approve(uid: UUID, body: Review, user=Depends(operator)):
    with db.connect() as c:
        row = c.execute('SELECT * FROM dtf_local.quotes WHERE id=%s FOR UPDATE', (uid,)).fetchone()
        if not row:
            raise HTTPException(404, 'Quote not found')
        if row['approved']:
            raise HTTPException(409, 'Approved quotes are immutable; request a new quote')
        draft = row['draft']
        if len(body.items) != len(draft['items']):
            raise HTTPException(422, 'Review must cover every item')
        items = []
        for item, original in zip(body.items, draft['items']):
            if item.mode != original['mode'] or list(map(str,item.uploads)) != original['uploads']:
                raise HTTPException(422, 'Product mode and attached files cannot change during review')
            for upload_id in item.uploads:
                require_clean(upload_row(c, upload_id, row['owner']))
            items.append({**price(item.mode, str(item.metres), item.grade), 'uploads': original['uploads']})
        quoted_freight = freight.quote(**draft['freight'])
        approved = {'customer': draft['customer'], 'items': items, 'freight': quoted_freight,
                    'total_cents': sum(i['total_cents'] for i in items)+quoted_freight['total_cents']}
        c.execute('UPDATE dtf_local.quotes SET approved=%s, reviewed_by=%s, approved_at=now() WHERE id=%s', (Jsonb(approved),user,uid))
    return approved

@app.post('/api/operator/orders/{uid}/move')
def move(uid: UUID, body: Move, user=Depends(operator)):
    with db.connect() as c:
        row = c.execute('SELECT * FROM dtf_local.orders WHERE id=%s FOR UPDATE', (uid,)).fetchone()
        if not row:
            raise HTTPException(404, 'Order not found')
        if body.version != row['version']:
            raise HTTPException(409, 'Order changed; refresh the board')
        if body.state == row['state']:
            return row
        if body.state not in TRANSITIONS[row['state']]:
            raise HTTPException(409, 'Move is not allowed from this state')
        if body.state == 'cor' and not body.reason.strip():
            raise HTTPException(422, 'Correction requires a reason')
        if body.state in ('fil','imp'):
            coverage = c.execute('SELECT DISTINCT f.item_index FROM dtf_local.order_files f JOIN dtf_local.uploads u ON u.id=f.upload_id WHERE f.order_id=%s AND f.kind=\'final\' AND f.active AND u.expires_at>now() AND u.purged_at IS NULL AND u.scan_state=\'clean\'', (uid,)).fetchall()
            if {r['item_index'] for r in coverage} != set(range(len(row['snapshot']['items']))):
                raise HTTPException(409, 'Approve a complete final-file set for every item before queueing')
        if body.state == 'cor':
            c.execute("UPDATE dtf_local.order_files SET active=false WHERE order_id=%s AND kind='final'", (uid,))
        c.execute('INSERT INTO dtf_local.movements(order_id,from_state,to_state,operator,reason) VALUES(%s,%s,%s,%s,%s)',
                  (uid,row['state'],body.state,user,body.reason))
        changed = c.execute('UPDATE dtf_local.orders SET state=%s, version=version+1, updated_at=now() WHERE id=%s RETURNING *', (body.state,uid)).fetchone()
        events = {'imp':'production_started','cor':'correction_needed','fin':'ready'}
        if body.state in events:
            for provider in ('tiny','whatsapp'):
                enqueue(c, f'{uid}:{changed["version"]}:{provider}', provider,
                        {'order_id':str(uid), 'number':row['number'], 'event':events[body.state], 'reason':body.reason,
                         'customer_path': f'/portal.html?order={uid}'})
    return changed

@app.get('/api/operator/orders/{uid}/history')
def history(uid: UUID, user=Depends(operator)):
    with db.connect() as c:
        return c.execute('SELECT * FROM dtf_local.movements WHERE order_id=%s ORDER BY id', (uid,)).fetchall()

@app.get('/api/operator/uploads/{uid}/download')
def download(uid: UUID, user=Depends(operator)):
    with db.connect() as c:
        row = c.execute('SELECT * FROM dtf_local.uploads WHERE id=%s AND complete', (uid,)).fetchone()
        if not row:
            raise HTTPException(404, 'Completed upload not found')
        if row['expires_at'] <= datetime.now(timezone.utc):
            raise HTTPException(410, 'Artwork retention expired')
        require_clean(row)
    return {'name':row['name'], 'url':storage.download(row['object_key'],row['name']), 'expires_in':300}

from .customer import install_routes
install_routes(app, operator, storage, begin_upload, upload_status, part_url, complete_upload, upload_row, STATES)