import hashlib
import re
from collections import Counter
from app.models.schematic import (Document, Sheet, Component, Symbol, Pin, SchematicObject, Diagnostic, Point)
from .ole_reader import read_document
from .images import read_images, asset_name
from app.models.schematic import Primitive
from .record_decoder import ParseError
from .geometry import point, flag, integer, coordinate, number, bounds, union, transform_point, color
from .primitives import decode, KINDS, SUPPORTED

ELECTRICAL=['Input','Bidirectional','Output','Open collector','Passive','Tri-state','Open emitter','Power']

def parse_schdoc(data: bytes, filename: str, document_id: str) -> Document:
    fmt,streams,main,extra=read_document(data)
    if not main or 'HEADER' not in main[0].properties:
        raise ParseError('Missing schematic version header')
    header=main[0].properties
    version=header['HEADER']
    if not re.fullmatch(r'Protel for Windows - Schematic Capture (?:Binary|Ascii|ASCII) File Version 5\.0',version):
        raise ParseError(f'Unsupported schematic version: {version[:150]}')
    records=[r for r in main+extra if r.index>=0]
    if len(records)>100000: raise ParseError('Combined record count limit exceeded')
    lookup={(r.stream,r.index):r for r in records}
    diagnostics=[]
    grouped={}
    def warn(code,message,r=None,severity='warning'):
        key=(code,r.properties.get('RECORD') if r else None,message if code not in ('unsupported_record','binary_record') else '')
        if key in grouped:
            grouped[key].count+=1
        else:
            try: record_type=integer(r.properties,'RECORD') if r and 'RECORD' in r.properties else None
            except ValueError: record_type=None
            d=Diagnostic(severity=severity,code=code,message=message,
                record_id=r.id if r else None,record_type=record_type)
            grouped[key]=d;diagnostics.append(d)
    images, image_errors = read_images(data)
    for message in image_errors: warn('embedded_storage', message)
    sheet_records=[r for r in records if r.properties.get('RECORD')=='31']
    if not sheet_records: raise ParseError('No schematic sheet record found')
    sheet_props=sheet_records[0].properties
    if len(sheet_records)>1: warn('multiple_sheets','Multiple sheet records found; only the first defines page properties')
    for s in streams:
        if s['name'] not in ('FileHeader','Additional','Storage'):
            warn('unhandled_stream',f"Uninterpreted OLE stream: {s['name']} ({s['size']} bytes)")
    if extra: warn('additional_indexing','Additional records use stream-local owner indexes; cross-stream ownership is not inferred',severity='info')
    components={}
    for r in records:
        if r.properties.get('RECORD')=='1':
            p=r.properties
            try:
                components[r.id]=Component(id=r.id,symbol_id=f'{r.id}:symbol',name=p.get('DESIGNITEMID',p.get('LIBREFERENCE','')),
                    description=p.get('COMPONENTDESCRIPTION',''),library_reference=p.get('LIBREFERENCE',''),source_library=p.get('SOURCELIBRARYNAME',''),
                    position=point(p),rotation=90*integer(p,'ORIENTATION'),mirrored=flag(p,'ISMIRRORED'),current_part=integer(p,'CURRENTPARTID',1),bounds=bounds([point(p)],5))
            except ValueError as exc: raise ParseError(f'Invalid component {r.id}: {exc}') from exc
    def owner_chain(r):
        chain=[];seen={r.id};current=r
        while 'OWNERINDEX' in current.properties:
            index=integer(current.properties,'OWNERINDEX',-1)
            parent=lookup.get((current.stream,index))
            if not parent: break
            if parent.id in seen: raise ValueError('Cyclic ownership')
            seen.add(parent.id);chain.append(parent);current=parent
            if len(chain)>64: raise ValueError('Excessive ownership depth')
        return chain
    # Collect component/sheet parameter values before resolving text expressions.
    parameter_maps={}
    for r in records:
        if r.properties.get('RECORD') in ('34','41'):
            p=r.properties
            try: chain=owner_chain(r)
            except ValueError as exc: warn('ownership',str(exc),r);continue
            c=next((components[q.id] for q in chain if q.id in components),None)
            key=p.get('NAME','Designator' if p.get('RECORD')=='34' else '')
            value=p.get('TEXT','')
            owner=c.id if c else 'sheet-0'
            parameter_maps.setdefault(owner,{})[key.upper()]=value
            if c:
                c.parameters[key]=value
                if p.get('RECORD')=='34': c.designator=value
                if key.upper()=='COMMENT': c.comment=value
                if key.upper()=='VALUE': c.value=value
    for c in components.values():
        c.value=c.value or c.comment
    objects=[];primitives=[]
    counts=Counter()
    for r in records:
        p=r.properties
        try:
            t=integer(p,'RECORD',-1);counts[str(t)]+=1
            chain=owner_chain(r)
            c=next((components[q.id] for q in [r]+chain if q.id in components),None)
            owner=lookup.get((r.stream,integer(p,'OWNERINDEX',-1)))
            active=True
            if c and r.id!=c.id:
                cp=lookup[(r.stream,int(c.id.split(':')[-1]))].properties
                for q in [r]+chain:
                    if q.id==c.id: break
                    part=integer(q.properties,'OWNERPARTID',-1)
                    mode=integer(q.properties,'OWNERPARTDISPLAYMODE',0)
                    if part not in (-1,0,c.current_part) or mode!=integer(cp,'DISPLAYMODE',0): active=False
            visible=active and not flag(p,'ISHIDDEN')
            if t==41 and any(q.properties.get('RECORD')=='48' for q in chain): visible=False
            if t==2 and integer(p,'PINCONGLOMERATE')&4: visible=False
            if p.get('TEXT','').startswith('='):
                key=p['TEXT'][1:].upper()
                value=parameter_maps.get(c.id if c else 'sheet-0',{}).get(key,parameter_maps.get('sheet-0',{}).get(key))
                if value is not None: p['_RESOLVED_TEXT']=value
            obj=SchematicObject(id=r.id,kind=KINDS.get(t,'unsupported'),record_type=t,source_stream=r.stream,source_index=r.index,
                owner_id=owner.id if owner else None,component_id=c.id if c else None,visible=visible,position=point(p),bounds=bounds([point(p)]),properties=p)
            if r.binary:
                warn('binary_record','Binary schematic record retained by index but payload is unsupported',r)
            elif t == 30 and visible:
                image = images.get(asset_name(p.get('FILENAME', '')))
                if image:
                    box = bounds([point(p), point(p, 'CORNER')])
                    shape = Primitive(id=r.id+':image', kind='image', bounds=box, object_id=r.id, component_id=c.id if c else None, image_data=image, keep_aspect=flag(p, 'KEEPASPECT'))
                    primitives.append(shape); obj.primitive_ids=[shape.id]; obj.bounds=box
                else: warn('missing_image', 'Embedded raster unavailable; external files are never fetched', r)
            elif t not in SUPPORTED:
                warn('unsupported_record',f'Unsupported schematic record type {t}; properties preserved',r)
            elif visible:
                shapes=decode(r,c.id if c else None,sheet_props,warn,lookup)
                primitives.extend(shapes);obj.primitive_ids=[s.id for s in shapes]
                if shapes: obj.bounds=union([s.bounds for s in shapes])
            if t==2:
                bits=integer(p,'PINCONGLOMERATE');length=coordinate(p,'PINLENGTH')
                end=transform_point(Point(x=length,y=0),obj.position,(bits&3)*90)
                obj.connection_points=[end]
                pin=Pin(id=r.id,name=p.get('NAME',''),number=p.get('DESIGNATOR',''),electrical_type=ELECTRICAL[max(0,min(7,integer(p,'ELECTRICAL')))],
                    position=obj.position,connection=end,length=length,rotation=(bits&3)*90,visible=visible,active=active)
                if c: c.pins.append(pin)
                else: warn('orphan_pin','Pin has no component owner',r)
            elif t in (26,27):
                n=integer(p,'LOCATIONCOUNT')
                if not 0<=n<=20000: raise ValueError('Invalid electrical point count')
                obj.connection_points=[Point(x=coordinate(p,f'X{i}'),y=-coordinate(p,f'Y{i}')) for i in range(1,n+1)]
            elif t in (17,18,25,29,37): obj.connection_points=[obj.position]
            if c:
                c.object_ids.append(obj.id);c.primitive_ids.extend(obj.primitive_ids)
            objects.append(obj)
        except (ValueError,OverflowError,KeyError) as exc:
            warn('malformed_record',f'Record not rendered: {str(exc)[:180]}',r,severity='error')
            objects.append(SchematicObject(id=r.id,kind='malformed',record_type=-1,source_stream=r.stream,source_index=r.index,
                visible=False,position=Point(x=0,y=0),bounds=bounds([]),properties=p))
    if len(primitives)>250000: raise ParseError('Drawable count limit exceeded')
    if not primitives: raise ParseError('No supported visible geometry found in this schematic')
    by_component={}
    for shape in primitives:
        if shape.component_id: by_component.setdefault(shape.component_id,[]).append(shape.bounds)
    for c in components.values():
        if c.id in by_component: c.bounds=union(by_component[c.id])
        else: warn('empty_symbol',f'Component {c.designator or c.id} has no visible supported symbol geometry')
    # Standard sheet presets in 10-mil units. Custom page dimensions win only when enabled.
    sizes={0:(1150,760),1:(1550,1110),2:(2230,1570),3:(3150,2230),4:(4460,3150),5:(950,750),6:(1500,950),7:(2000,1500),8:(3200,2000),9:(4200,3200),10:(1100,850),11:(1400,850),12:(1700,1100),13:(990,790),14:(1540,990),15:(2060,1560),16:(3260,2060),17:(4280,3280)}
    style=integer(sheet_props,'SHEETSTYLE')
    if style not in sizes and not flag(sheet_props,'USECUSTOMSHEET'): raise ParseError('Unsupported sheet dimensions')
    w,h=sizes.get(style,(1150,760))
    if flag(sheet_props,'USECUSTOMSHEET'):
        w,h=coordinate(sheet_props,'CUSTOMX'),coordinate(sheet_props,'CUSTOMY')
    if integer(sheet_props,'WORKSPACEORIENTATION') and w>h: w,h=h,w
    if w <= 0 or h <= 0: raise ParseError('Sheet dimensions must be positive')
    page=bounds([Point(x=0,y=-h),Point(x=w,y=0)])
    content=union([s.bounds for s in primitives])
    if flag(sheet_props,'BORDERON') or flag(sheet_props,'TITLEBLOCKON'):
        warn('page_decoration','Automatic Altium page border, zones and title block are not reconstructed. Explicit template geometry is rendered.')
    try:
        if 'WEIGHT' in header and int(header['WEIGHT'])!=len(main)-1:
            warn('record_count_mismatch',f"Header declares {header['WEIGHT']} records; found {len(main)-1} in FileHeader")
    except ValueError: warn('record_count_mismatch','Header record count is not numeric')
    warn('connectivity_scope','Connection anchors and wire vertices are extracted. Net names are not a compiled netlist; bus expansion, harnesses and cross-sheet connectivity are not resolved.',severity='info')
    warn('font_metrics','Exact original fonts are required on the client. Font size conversion and glyph metrics have not been validated against Altium.',severity='warning')
    warn('pin_text_metrics','Default pin text offsets and port text anchors require validation against a trusted Altium export.',severity='warning')
    return Document(id=document_id,filename=filename,
        metadata={'format':fmt,'header':version,'minor_version':header.get('MINORVERSION'),
            'sha256':hashlib.sha256(data).hexdigest(),'input_bytes':len(data),'streams':streams,
            'record_counts':dict(counts),'record_count':len(records),'component_count':len(components),
            'primitive_count':len(primitives),'units':'10mil','coordinates':'X right, Y down; Y inverted once from Altium',
            'compatibility':'partial' if any(d.severity in ('warning','error') for d in diagnostics) else 'supported_subset',
            'header_properties':header},
        sheet=Sheet(name=filename,background=color(sheet_props.get('AREACOLOR','16317695')),properties=sheet_props,bounds=page),bounds=content,
        components=list(components.values()),symbols=[Symbol(id=c.symbol_id,component_id=c.id,primitive_ids=c.primitive_ids) for c in components.values()],
        objects=objects,primitives=primitives,diagnostics=diagnostics)