// app/bridge_server.prg — file-name dispatcher.
//
// Translates the HTTP request hash into the ctx fields the mod_harbour
// AP_* layer expects, then calls the per-path Main symbol that
// fnode auto-renamed (app/api/foo.prg → FOO__MAIN). PRG handlers in
// app/api/ stay unmodified — they keep their `FUNCTION Main()` shape
// and use AP_METHOD/AP_BODY/AP_JSONRESPONSE/ctx_get/... freely.

FUNCTION Main()
   LOCAL cDsn := hb_GetEnv( "LABDB_DSN", "postgres://" + hb_GetEnv( "USER", "" ) + "@127.0.0.1:5432/labdb?sslmode=disable" )
   LOCAL nH, cErr

   ? "labdb: opening PG", cDsn
   nH := PG_OPEN( cDsn )
   IF nH < 0
      ? "labdb: PG_OPEN failed (handlers will see empty ctx — server still starts)"
   ELSE
      ? "labdb: PG handle =", nH
   ENDIF
   LABDB_SET_PG( nH )

   cErr := HTTP_SERVER_START( ":8090", "BRIDGEDISPATCH" )
   IF cErr != NIL
      ? "httpserver:", cErr
   ENDIF
RETURN NIL

FUNCTION BridgeDispatch( hReq )
   LOCAL hCtx, cFunc, cErr

   hCtx := { ;
      "method"       => hReq[ "method" ], ;
      "filename"     => hReq[ "path" ], ;
      "query_string" => hReq[ "query" ], ;
      "body"         => hReq[ "body" ], ;
      "remote_ip"    => RemoteIPOnly( hReq[ "remote_addr" ] ), ;
      "headers_in"   => hReq[ "headers" ], ;
      "headers_out"  => { => }, ;
      "status"       => 200 ;
   }
   FetchRouteData( hReq[ "path" ], hCtx )

   _CTX_SET_JSON( hb_jsonEncode( hCtx ) )
   _OUT_CLEAR()

   cFunc := PathToFunc( hReq[ "path" ] )
   IF Empty( cFunc )
      ctx_set( "status", 404 )
      AP_JSONRESPONSE( { "error" => "no handler for path", "path" => hReq[ "path" ] } )
   ELSE
      cErr := FNODE_CALL( cFunc )
      IF ! Empty( cErr )
         _OUT_CLEAR()
         IF "not found" $ cErr
            ctx_set( "status", 404 )
         ELSE
            ctx_set( "status", 500 )
         ENDIF
         AP_JSONRESPONSE( { "error" => cErr, "func" => cFunc } )
      ENDIF
   ENDIF

   RETURN { ;
      "status"  => ctx_get( "status", 200 ), ;
      "headers" => ctx_get( "headers_out", { => } ), ;
      "body"    => _OUT_GET() ;
   }

// FetchRouteData runs the per-route SQL the matching server.js endpoint
// would have run and drops the values into ctx fields the corresponding
// PRG handler reads via ctx_get(). Routes without a SQL block here fall
// through to whatever default the handler uses (which is what 1a.4-3
// validated). Extend by adding cases as more endpoints come online.
FUNCTION FetchRouteData( cPath, hCtx )
   LOCAL aRows
   LOCAL nPG := LABDB_GET_PG()

   IF nPG < 0
      RETURN NIL
   ENDIF

   DO CASE
   CASE cPath == "/api/admin-stats.prg" .OR. cPath == "/api/admin-stats"
      aRows := PG_QUERY( nPG, "SELECT (SELECT COUNT(*) FROM devices) AS devices, (SELECT COUNT(*) FROM sessions) AS sessions, (SELECT COUNT(*) FROM records) AS records, (SELECT COUNT(*) FROM sessions WHERE status = 'active') AS active_sessions" )
      IF aRows != NIL .AND. Len( aRows ) > 0
         hCtx[ "devices" ]         := hb_NToS( aRows[ 1 ][ "devices" ] )
         hCtx[ "sessions" ]        := hb_NToS( aRows[ 1 ][ "sessions" ] )
         hCtx[ "records" ]         := hb_NToS( aRows[ 1 ][ "records" ] )
         hCtx[ "active_sessions" ] := hb_NToS( aRows[ 1 ][ "active_sessions" ] )
      ENDIF

   CASE cPath == "/api/sessions-list.prg" .OR. cPath == "/api/sessions-list"
      aRows := PG_QUERY( nPG, "SELECT session_id, device_id, session_name, start_time, end_time, record_count, status FROM sessions ORDER BY start_time DESC LIMIT 50" )
      IF aRows != NIL
         // sessions-list.prg reads ctx_get("rows", "[]")
         hCtx[ "rows" ]  := hb_jsonEncode( aRows )
         hCtx[ "total" ] := hb_NToS( Len( aRows ) )
      ENDIF

   CASE cPath == "/api/admin-devices.prg" .OR. cPath == "/api/admin-devices"
      aRows := PG_QUERY( nPG, "SELECT device_id, device_name, api_key, is_active, created_at FROM devices ORDER BY created_at DESC" )
      IF aRows != NIL
         hCtx[ "rows" ] := hb_jsonEncode( aRows )
      ENDIF
   ENDCASE
RETURN NIL

// /api/admin-stats.prg  -> ADMIN_STATS__MAIN
// /api/hello.prg        -> HELLO__MAIN
// /api/hello            -> HELLO__MAIN (extension optional)
// Returns "" when the path can't be mapped (caller turns into 404).
FUNCTION PathToFunc( cPath )
   LOCAL cBase, n
   IF SubStr( cPath, 1, 5 ) != "/api/"
      RETURN ""
   ENDIF
   cBase := SubStr( cPath, 6 )
   IF Right( cBase, 4 ) == ".prg"
      cBase := Left( cBase, Len( cBase ) - 4 )
   ENDIF
   IF Empty( cBase )
      RETURN ""
   ENDIF
   cBase := StrTran( cBase, "-", "_" )
   // Defensive: refuse anything outside [A-Z0-9_].
   FOR n := 1 TO Len( cBase )
      IF ! ( IsAlnum( SubStr( cBase, n, 1 ) ) .OR. SubStr( cBase, n, 1 ) == "_" )
         RETURN ""
      ENDIF
   NEXT
RETURN Upper( cBase ) + "__MAIN"

FUNCTION IsAlnum( c )
RETURN ( c >= "0" .AND. c <= "9" ) .OR. ;
       ( c >= "A" .AND. c <= "Z" ) .OR. ;
       ( c >= "a" .AND. c <= "z" )

FUNCTION RemoteIPOnly( cAddr )
   LOCAL n
   IF Empty( cAddr )
      RETURN ""
   ENDIF
   n := RAt( ":", cAddr )
   IF n > 0
      RETURN Left( cAddr, n - 1 )
   ENDIF
RETURN cAddr